Concerned about electrical fires

[Arberg0]

From: Derrek  (Original Message) Sent: 4/27/2003 8:11 AM

Hello All
        The engine fire thread on the main message board had really got me thinking about the possibilities of a fire. I have seen the knife switch style battery disconnects in auto parts stores that connect directly to the battery terminal and was wondering if someone makes a circuit breaker that will install in the same place and disconnect the batteries in the event of a short?

The only problem with this is that it would have to be sized large enough to allow the engine to be cranked using either battery. I read that cranking amperage on a dodge starter on one of these motorhomes will range between 100 - 250 amps. Does that sound correct? I can't help but think that a fuse or breaker rated that high would offer little fire protection?! Any ideas? Can someone educate me a little more on the subject.

I got a first hand look at the damage that can be caused by the high amperage produced by automotive batteries this past winter. There is a slot car race track located near my home and while my nephews and I were there we saw a kid hook up the controller wrong (three seperate wires with alligator clips) sending full amperage of the car batteries used to power the track through the controller. The controller and all of the wiring under the track instantly began smoking and  burst into flames filling the place full of smoke. The owner had just rewired the track and thought by bypassing the circuit breaker he could get more amperage to the cars and get them to go faster.

Sorry for the long post but when it comes to the safety of my family or maybe being able to help someone else and their family I feel that we cannot say enough. The thought of a motorhome fire scares the crap out of me!!!!! 




From: chip Sent: 4/27/2003 12:58 PM
you have a right to be concerned about fires in our old winnies. i have been told by a pretty well informed source that winnebago blundered in using the blue type filler/foam in the roof and wall panels. as i understand it, when the panels were tested for the fire rating, they set flat[horizontally], and they rated quite well.
well, after a few "winnie meltdowns" the panels were tested verically. BIG difference! they went up like a roman candle. now combine that with a single entrance/exit, the insurance companies were having coronarys.
my solution for battery disconnect and charging was to use a marine disconnect switch and a wirth 3 position knife switch. this way i can switch either battery for the house system or the engine, disconnect all, or use both batteries together. personally, i've had nothing but bad luck with isolators, so i made my electrical switching system "manual".

 

From: denison Sent: 4/27/2003 3:29 PM
I think the peak current your starter might need on a cold day could be 400 amps. I doubt there would be any use having such a fuse or cktbrkr in the battery line. I can imagine removing the main battery feed cable from your batteries up to what ever form of starter relay the RV has, and putting in a thick new one, carefully installed with insulated cable supports, good terminals, etc.
. On the 72 and later Dodge chassis, there is a fusible link from that starter relay that feeds everthing else, and if it gives way, it removes power from everything except the battery cable. That link is 14 gauge, the rest of that circuit is 10 gauge. By the way, all the current from your alternator, when charging both batteries, has to go through that 14 gauge fusible link - I bet it gets pretty warm - but not to worry, it is down low, away from the fuel line, and its insulation is a type that melts, doesn't burn. There was one of us who had the fusible link blow, and I think they said they wired around it. I hope they then bought a new fusible link and put it in. Or at least a circuit breaker in its place. Now that you have brought this up, I think I will carry a fusible link as a spare part, and I might see about a new main battery cable - a nice 00 gauge with teflon insulation, in a bright red color. The 71 and earlier Dodge chassis didn't seem to have any form of fusible link. !!! My way of switching the batteries is to unbolt the positive terminal from the top of it. denison 


 

From: Derrek Sent: 4/27/2003 10:23 PM
Thanks for the replies. I was not aware of that fusible link. Do you know what the amperage rating for that would be? Not that it really matters and hope I never find out, but I am curious. So I guess all that is left to check is the various wiring installed by the different owners through the years and make sure they used some type of fuse.   

Thanks again for your replies. At least now I feel a bit more at ease. Although nothing can substitute the reassurance of a complete inspection of the condition of the wiring harness,fuses...ect. I will add another item on my to do list......

 



From: cartinkr Sent: 4/28/2003 5:52 AM
Ive no idea of the fusible link rating.  I have seen them in the auto parts stores that have a lot of aftermarket goodies on racks, Id see how they describe their sizes. Look for one rated as a 14 gauge maybe?  Considering the alternator can put out 60 to 75 amps briefly, its a little suprising the fusible links hold up.   My 1984 plymouth has about 5 of them, all smaller in capacity I imagine.  I had one of them blow, due to a short in the main ignition circuit.  I put in a circuit breaker, cause I couldn't find the short - it was intermittent.  After the thing died when my daughter was driving it, I went on a serious search, found a wire chafing against the sharp edge of a stamped bracket.  I had worked on the car enough that I could have been the one who routed that wire to one side of the bracket instead of the other side - which didn't have the sharp edge.            denison


 

From: Collyn down-under Sent: 4/30/2003 10:41 PM
It's not a good idea to have a switch or fuse or contact breaker in the lead from the battery to the alternator. Most alternators need battery voltage as a reference and if this is broken whilst the engine is running the alternator is very likely to go instantly to over 100 volts.

With luck this will only take out the alternator, but it can also damage equipment. Further, this sort of voltage level can be lethal.

Likewise if arranging switching between two alternate batteries you must use a switch that makes the next connectioin before breaking the first. This is not a good set up anyway - better by far to use a solenoid switched via the ignition
Collyn down-under


 

From: Graham Sent: 6/11/2003 10:22 PM
Hi all,

After Rick's experience, I've been checking my wiring. Behind the dash was an aweful mess but I've changed uninsulated spade connectors and taped crimped connectors. I found two "hot" wires disconnected, one to the cigar lighter and the other for the removed radio.

Coming out of the side wall by the driver's feet, there are five wires going nowhere, black, grey/tan?, yellow, purple and pink. There used to be a generator, and I wondered if these were for a genset?? Any ideas?

Also, I want to fit a rev counter but don't know if they are difficult to wire up?

My rig runs on propane and I don't know if a vacuum gauge would be worthwhile? Would the readings and diagnostics be the same as with a gas motor?

When I started the motor today, the oil pressure gauge went to the right of the "norm" segment. Is this correct? The oil is clean and up to the full mark on the dipstick. If I substitute a gauge with pressure levels, what should the idle pressures be when cold and when at operating temperature?

In a previous thread, I think someone warned about the converter overcharging the coach battery while on shore power. Is my memory correct and if so, how do I disconnect the converter from charging?

Many thanks and God bless,
Graham






From: Collyn down-under Sent: 6/11/2003 11:59 PM
Brief comments re wiring safety.

Firstly it's really worthwhile taking this seriously with oldish vehicles - as the insulation tends to harden and break down. When that happens it may short out and cause a fire.

As Denison says starting current is more likely to be 400 amps (at 12 volts) and 200 amps (at 24 volts). I'd not be surprised to see that even on a warmish day. (if it's as low as 150 amps or so, it's because there's no worhwhile compression to cause a load!).

It's possible but not practical to protect starter cabling against short circuits. Follow Denison's advice and renew the main starter cable and associated earth (I think you call them 'ground' leads in USA?). Take care to support them against vibration.

It may be worth adding an additional earth/ground lead from the starter motor frame to the chassis as contact here may be not as good as hoped for. You can check if it's worthwhile by running a jumper cable temporarily and seeing if the starter motor spins any faster.

Re remainder of wiring.

The ideal is to use circuit breakers in main circuits. These are sized to protect the cables and are inserted as close to the battery end of the cable as possible.

Fit fuses as close as possible to each major appliance. Fuses are sized at about 50% higher than the rating of the guarded appliance.

As boo boo will tell you It's all in my 'Motorhome Electrics' book - forgive the plug - but there's not much published re this otherwise even in your otherwise admirable country - even though non-metric.
Collyn down-under


 

From: dave76Chieftain Sent: 6/12/2003 6:35 AM
Please note that you cannot use an AC circuit breakers in place of a DC circuit breaker.  They are not rated the same way.  DC breakers can be a bit hard to locate.  Normal automotive catelogs typically do not list the kind you can mount in panel and be able to shut them off with a toggle handle.  The auto catelogs basically only show the auto reset box shaped style that you cannot turn off.  You usually have to look under boating supplies to find toggle/rocker style breakers.  Be sure and look around a bit because they vary in price.

Dave




From: Graham Sent: 6/14/2003 2:34 AM
Thanks for the info guys - sorry to post all over the place but some questions cover many sections.

Oil pressures - thanks - summer here in Alberta, I'll use 20w50 and winter I'll use 10w 40 or 5w30.

OIL question - my 73 Brave 440 dipstick seems to be made of aircraft wire with a little flat bit at the sump end. Is this the standard and if so, how long should it be from loop to tip?

COOLANT question - coolant is green and feels very slimey. Overflow bottle is empty. I assume, I shouild fill to the cold (lower) level and see what happens??
I'm told a coolant circulating heater is superior to a block heater. I know most of you don't know what winter is but has anyone any experience to share? Cold propane is tricky to start apparently.

Windshield washers question - pump whirs but nothing comes out. Plastic bottle is almost FUBAR. Has anyone replaced with a car set up and if so any suggested models. Not concerned with concours parts.

FREE - someone wanted star burst ?? clearance lights. I've replaced mine and have lenses and some useable backings for the postage from Canada. - Going on hols on June 30 so let me know asap please.

Dash and steering column rewiring now finished and heater cable fixed. Still concerned about the wires into the side wall - they match the ones from the steering wheel???
Rewiring was a three day effort, with connector replacement, wire replacement, layout revisions, sharp edge protectors (sticky 1" neoprene weatherstrip and plastic sheets (snow crazy carpet) and 20' of 0.5" cable cover sleeving held in place by dozens of plastic cable ties. I replaced several lengths of wire where the outer insulation had softened and melted itself to a neighbouring wire. I thought that fuses stopped wires getting that hot. I have all the correctly rated fuses in the fuse box. The circuit for the cigar lighter is marked interior lights and has a 20A fuse. Is this too high?

ELECTRICAL question - prior owner had wrapped several revolutions of electrical tape across the top of the screwed in cable cover just below the bowl-like unit beneath the signal/ignition thingy on the steering wheel. Any ideas why?
There is a .5" dia hole which was covered??

Nother ELECTRICAL question - the gauges appear to have card/paper backings. Is this OK or should I replace with plastic sheet cut to fit?? Getting fire paranoia now!!

In the same vein, the passenger footwell light on my rig is mounted to the underside of the lower dash rail, on a piece of wood - approx 2.4x.75x.75". The light is under the glove box and the unglued leatherette edging is hanging down over the bulb. I cannot believe this was the original design. Does anyone have any safer suggestions?

Still no replies to my classified ad for a genset - preferably one converted to run on LP and give 4KW - there's got to be one somewhere??

To do list grew today when talking to a very knowledgeable man about LP conversions. Seems I should have a special LP gas sticker - without which one should be unable to buy the stuff, and annual recertification of the tank each one or two(??) years. They can do a tank to motor inspection and CO emissions test/tune up so I'll get that done next.

One day this year () I'll go on a camping trip - I just keep telling myself this is good depression therapy even if it takes me ten times longer than it used too!!

Thanks in advance for any more tips and advice, God bless,
Graham
PS I think I'll sign up for yoga lessons to help bend into the awkward poses necessary to reach under the dashboard.




From: Derrek Sent: 6/14/2003 7:46 AM
Graham
               Just wanted to start by saying that I am certain there are many people at this site including me who are following your posts and your story and cheering you on every step of the way. I am confident that you will be out camping in your rig soon and by reading your post I am sure that the repairs and upgrades in your rig will have been done right.

I like the way you think. Many people don't even bother to check the engine oil in their rigs. Not only do you check it, but you then take it one step further and question whether or not the dipstick is the correct length and the readings are accurate. As I recall the dipstick on my Brave was the same type that you are describing but I do not know the length. Another member will have to help you with that one.

As far as the coolant, I would ensure the radiator is topped off first. Then once the engine is at operating temp check the level in the overflow bottle and fill if needed. Don't know much about heaters....again maybe another member can help out in this area.

You should be able to pick up an entire windshield washer replacement at a local auto parts store. It should include a new bottle and pump. I will need to replace mine soon. The plastic has become brittle from the heat of the radiator.

As far as the fuse for the cigar lighter. I think that the service manual should list the recommended fuses and the rating of the fuses from the factory. Electrical systems are not my strong point.

My Brave did not have a light below the glove box so I assume someone added that light.

There is nothing better than being wedged between the seat and the dash with a brake and gas pedal in your upper back and an engine cover in your lower back and then suddenly you get that unbelieveable cramp that forces you to fight you way out of a position that it took you 5 minutes to get into in less than 10 seconds........    




From: denison Sent: 6/14/2003 12:32 PM
Graham: We dont have real winters here in Virginia, but I would first add a battery heater to help in cold weather starting, before I added a block heater or circulating heater. Lead acid batteries lose efficiency as they get colder, and I think the drop in the batterys ability to change stored chemical energy into amps into the starter drops dramatically. You warm up the battery beginning a few hours before you want to start up the motorhome - or your car. Its also easier to add a battery heater!
Also, if I want to start up on a cold cold morning, I pour a 1/2 pint of kerosene into the engine oil before I shut it off the day before. This thins out the oil without hurting anything, so the engine will crank over a little better in the morning, and the kerosene will evaporate in a couple hundred miles of driving.
I know there are two types of home heating gas fuel sold in the U.S. One type is for the south, where it doesn't get below +10f in a century, the other type is for places like North Dakota, where -40f is not a record, and you need a gas that boils at a lower temperature than that. The gas burns the same, but has the different boiling point, and different peak pressure. I would presume the lp gas you would buy in winter in Edmonton would be formulated to have a boiling point below what the lowest air temp was to be. I would hope that would solve the problem of your lp gas not having enough pressure at the throttle body assembly when you go to start it. And maybe a warm air blower aimed at the throttle body?
My dipstick was made of what looked like choke cable -a wire spiral- , with a flat piece brazed to the end - which was the end of the original dipstick I think. Winnebago just modified the dipstick so you could check oil level from the front of the engine. Regular dipsticks are flat metal, and bend happily in one plane - but to come out the front of the motorhome they have to bend in both planes, and the flat original kind dont seem to work. That brazed end broke off mine once, fell into the pan - which wont hurt anything. As a replacement I got a regular choke cable and cut it down to fit. A homemade handle at one end, the other end sticking down one inch into the oil. My homemade dipstick is 47 inches from tip to the handle where it seats on the end of the dipstick tube - the full level is one inch up from the end. There might be various lengths, depending on how much Winnebago extended the dipstick tube when they made your RV. I think the correct amount of oil is 6 quarts if you dont change the filter. If you put in a quart too many it wont hurt anything. If you put in 2 or 3 quarts too many you may find that your oil pressure drops alarmingly when you are cruising along the highway, but returns to normal when you pull over and coast along at slow speeds. This is because the oil level is too close to the crankshaft, and the windage is entraining air into the oil. The foamed oil cant be pumped as effectively, so although you still have plenty of oil moving, your oil pressure can temporarily fall, and when the foam gets into your lifters, you may hear some valve clatter. Cure: slow down, find a spot to drain out some oil. I am pretty sure you wont have hurt anything if you dont persist in doing it.
If your overflow bottle is empty, you should put coolant in it - green and slimy is correct, and poisonous to small animals, birds and cats will drink the stuff - and look for the reason that bottle is empty! Be sure to check that the coolant level in the top of the radiator is high enough. With the coolant recovery systems, the coolant in the radiator should be right up to the level of the cap. However, if the coolant recovery hose is old and dried out, it may not be sucking the coolant back into the radiator as the engine gets cooled down after use. You might not be able to depend on it working. The coolant level in the recovery bottle should be higher when the engine is hot, lower when the engine is cold. If not, the little connecting hose may have an air leak, your radiator cap may be senile, or you might have a very small leak in the cooling system that lets air in as the engine cools off at night. I would check that all the radiator hose clamps and heater hose clamps are snug. And putting in a small can of a radiator stop leak wont hurt either. I like Barrs, in the gray plastic bottles.
About your wiring gluing itself together. How close were these wires to the exhaust manifold or exhaust pipes? I used a few cable ties and some homemade metal brackets, to hold the main bundle going through the drivers side of the engine compartment, up high, above the level of the rocker covers, on the left side of the motor cover opening. Also, if the wires get a lot of oil on them, the plastic will soften and -creep- in its shape when the engine has warmed everything up. A cigar lighter fuse of 20A sounds right. All we use that for is recharging the cell phone. Remember, being marked -interior lights- refers to the dome light that a Dodge truck/van would have had - not to the coach lights in the winnebago.
Ive no idea about the tape wrapped around the thingy on the steering column. My column has electrical tape wrapped around to keep the column wiring away from my feet.
The gauges have a hard paper based insulation backing - real stiff stuff. This is normal. The passenger side footwell light on mine sounds the same as yours. I cut away the drooping leatherette, that was probably once glued up out of the way.
I would check whether the lp gas tank recertification applies to private owned vehicles, or only to commercial vehicles. I can believe the recertification is a good idea though.
The yoga lessons sound like a good idea - my wife recommends I lose 40 pounds. First I want to see what the yoga instructoress looks like.
I have added a chore to my ToDo list - remove the seat supports, and rework the bolts, so I can unscrew them from inside, not from under the floor. This will make it easier to do that dashboard work. With the seat out, and the seat support out, I can lie flat there, except that my feet with be drawn up. I will have the wife supply me with milk and oreo cookies.
The hardest thing about a rev counter is where to mount the dial! There are two common kinds of electrical rev counters. Both connect to 1. a wire that is 12v when the ignition is on, like the radio supply, and 2. to ground. One of them also has a wire that connects to the negative labelled ignition coil wire. The other type is -inductive- and has a small item that slips over one of the spark plug wires. Neither type will work with diesels, only engines with spark plugs. The -inductive- kind might be a little more expensive, but will work with any form of electronic ignition system, even the late model cars that dont have distributors.
A vacuum gauge would work as well on your lp gas powered engine as on a gasoline powered engine.
If you leave the 20W50 oil in the motor and go to start it on a chilly day, it may misfire and not run on all 8 cylinders for a while - because the 20W50 oil in the lifters may not bleed down enough, keeping the valves from closing all the way. This will not hurt anything, and will go away as the oil gets warmed up. If you change to the lighter weight oil, it can take half an hour of driving for the thick oil in the lifters to fully mix-out with the new thinner oil you put in the crankcase. denison





From: Tarsand traveler Sent: 6/15/2003 12:30 PM
Graham , I am interested in finding out where and what the cost will be to recertify your propane system. I am in Fort McMurray and am running a '76 Brave  440-3 on propane. I will also need to have an inspection soon. I would appreciate it if you post how you make out with this.
Thanks
Hugh




From: Collyn down-under Sent: 6/16/2003 2:55 AM
Denison
My wife is a yoga teacher - and looks stunning. But if you want to check you'll need to book into her classes in Broome!
Collyn down-under


 

From: robobob Sent: 6/16/2003 4:35 AM


i might take you up on the offer, but not this year, dont worry.