Water Pump Conversion

[legomybago]

The fan is always moving some air, clutch engaged or not. If you have a clutch fan that is engaging off/on while idling in your driveway, your engine is running too hot, or you have the wrong clutch installed. MO. Clutch fan operation is for hill climbs or a (hard working motor), heat soak, and cold starts due to cold internal oil. Other than that, you shouldn't hear it much. This has been my experience with proper clutch fan operation. Being that we are talking about Class A motorhomes, some clutch fan "at idle" wouldn't really surprise me, there is a ton of heat under that dog house and everything is so buried in the front. My P30 doesn't do this, but my cooling system is only 4 years old too....so who knows.

[Rickf1985]

Or you can manually engage the fan clutch.

[legomybago]

Or you can manually engage the fan clutch.

Throw a rag into it?? W%

[legomybago]

I was making a joke. :)rotflmao guys...I would never throw a rag into a running engines fan.
I've heard of people grabbing a clutch/fan assembly while the engine is running WITH there hands for a testing procedure!! People are weird when it comes to clutch fans....Seriously...

[WyzrdX]

Alternators usually just stop working at all, lock up, put out max voltage, or pulse, etc when they die.  They have some quantifiable problem.  What do you mean it's not charging?   I would sooner suspect the battery is in need of replacement.  They don't last forever.   How old is the battery?  If it's over 4 years or so, it's due for replacement.

When I say its not charging I mean the gauge is showing approx 10A output and as a test, I started it and let it run for about an hour with the headlights on. It was right at nightfall and we watched the headlights basically go so dim you could not see the bumper.
I took the battery (which was purchased in January) to the O'Reilly and the battery was tested as good but near dead. The next morning I started it and while it was running, I disconnected the battery. It died. Indicative of bad Alternator.

This is going to save you a bunch of work:  it's not the water pump causing your elevated running temperature.  They don't stop pumping when they go bad, they leak out the weep hole on the snout.  This would be a waste of time and money, don't change it.

OK I have seen no leakage of any kind. So I will reconsider that decision.

   
• Remove Mechanical Fan and adding 2 Thermostatically controlled Electric Push Fans

Don't do this, waste of time and money.  The factory engineers knew what they were doing.  Do replace the fan clutch, they don't last forever and a weakly engaging one could cause the symptoms you are seeing.  They are a bit of coin, I think the one I got was like $90 for the AC Delco brand.  Don't buy junk, you'll regret it.

Already decided against this.

   
• I also want to replace the Fuel Filters.

Good idea, if your 88 is the same as my 90 this is in your front-most passenger side baggage compartment.  Remove the two screws holding on the carpeted rectangle of plywood facing the door, the filter is behind it on the frame.

That helps. Ill look tomorrow.

Rick brought up the fuel regulator, I haven't touched mine but it may be located on the passenger side back near the fill neck.  I think I saw it last night near the tag axle and frame, if it's like my 1990. 

Mine doesnt have the tag axle but I'll look in the same vicinity.

Thanks for the input TM.

I am leaning to it being a bad fan clutch from what everyone is saying. And that will be an easy fix. As for the alternator, a bit more to it but doable. Hate the position I have to be in but that's ok I will have a scotch when I am done.

[Rickf1985]

I was making a joke. :)rotflmao guys...I would never throw a rag into a running engines fan.
I've heard of people grabbing a clutch/fan assembly while the engine is running WITH there hands for a testing procedure!! People are weird when it comes to clutch fans....Seriously...

This can be done but you have to know what you are doing or you will lose fingers. And at best even knowing what to do you could get stinging fingers if the clutch kicks in at that particular time. It is something you do to impress the uninitiated. there are much better ways to test the clutch.

[WyzrdX]

Well considering the battery tested good but needed to be charged and it is only a few months old it takes me back to its a bad alternator.

[turbinebronze]

We would do a quick check of the alternator by running the vehicle at 2000rpm (alternators are designed to have max output at that engine speed), and turn on all the heavy load 12 volt systems (hi beam headlamps, heater blower on hi, etc..) and watch a digital volt meter on the battery. It should hold 13.5-14.0 volts with a fully charged battery. At idle, the battery should carry the load for a short period of time. (12.6 volts is a fully charged batt.) This is not a pass/fail for the alternator, but if is not putting out, your battery voltage will drop quickly.
  Just my 2 cents, Craig.

[DaveVA78Chieftain]

Well considering the battery tested good but needed to be charged and it is only a few months old it takes me back to its a bad alternator.

Maybe, maybe not.
The B+ lead from the alternator goes to the large B post on the starter solenoid. However, there is a fusible link at the starter solenoid that will result in the alternator not working if it has blown.  With the engine off, make sure you have battery voltage at the alternator B+ terminal at all times (key ON or OFF).  No voltage means the fusible link has blown.  Also, the fusible link can start going bad due to heat and age (lots of current going through it) resulting in high resistance and screwing up the charging circuit.
On the small wire alternator plug, the Pink/Black wire (from ignition switch) should have 12VDC on it with key ON, engine OFF.  In most applications the small wire comes from the idiot light.  If an idiot light is not installed, then this line has to have 35 ohms resistance in it.

If you have the DUAL-NORM-MOM switch on the dash, then Charging of the House battery is via the Dual battery solenoid however, the battery B+ lead from the starter solenoid and the B+ lead from the chassis battery should be connected to the same post on the dual battery solenoid.

You most likely have a 1988 rig on a 1987 chassis (check chevy chassis VIN to confirm).  Your a Life member so the the service manuals for that chassis are in the member area for free.  However, the 1987 wiring diagrams are alomost impossible to decipher so I would use the 1988 drawing.  It will be 98% correct.
Power wiring diagram for the 1988 P30 Motorhome chassis (P32 model) is Section E, page 3
The small alternator plug connection is shown on Section E, page 17.

[Rickf1985]

Disconnecting a battery while running is a good way to screw up a lot of stuff, alternator included. The battery acts as a buffer to the voltage put out by the alternator. You pull that cable off and there is going to be a spike. could be small, could be huge. Electronic do not like spikes and neither do the diodes in the alternator. That is something that carried over from the generator days and for some reason people will just never learn.

[WyzrdX]

Turbine

I did check the voltage at the battery and I am getting approx. 9.6 - 10.2 A at the battery.



Dave

I do have an 88 on an 87 Chassis.
I have all of the manuals that came with it and from what I have seen the wiring diagram seems to be pretty accurate.
I have not checked for a fusible link but I will this weekend if I have a moment. I do not have the dual-norm-mom that I had on my Winnie. I do have an Alternate Start switch that allows me to use the house batteries for a jump so to speak.

[DaveVA78Chieftain]

I do have an Alternate Start switch that allows me to use the house batteries for a jump so to speak.

Then do you by chance a Diode battery isolator that allows the Alternator to charge the house battery?



As you can see from the top drawing, the alternator connects via the isolator if you have one which could also create a no charge condition if the isolator diode is defective.

[WyzrdX]

I just finished installing a new Maxxfann and have not had a chance to look but as soon as I do I will report back. Although I may be asking for assistance in identifying. If I cant figure it out I will post pics to see what I have.

[WyzrdX]

OK since I had a few days to work on it I was able to get my Brother-in-Law out to assist. He works for a mobile RV repair company and he had a day off to help.


It appears it is the Alternator. There is a battery isolator which we pulled along with the alt. Both were tested at his shop and the isolator was good but alternator was bad. And I realized I need a new battery cut-off.


My question is should I replace the isolator as a precaution? It looks a bit old and like it has been through a flood. (ie. rust in places)

[DaveVA78Chieftain]

As far as the electronic portion (diodes), those pieces last for years and rarely fail unless something happens that degrades them.  A large current spike could damage it.

As far as the rust, that would be the major concern.  Corrosion is the bane of electronic equipment that results in bad connections.

[Rickf1985]

I posted but it did not go through but this kind of goes along with what Dave says. I would say that a modern version with more advanced electronic controls would probably be a good bet. My main concern would be the voltage spikes. You have disconnected the battery while it was running which is most likely what took out the alternator since that is usually what happens. It also would have given that isolator a shot so it has been hit at least once with a spike. You cannot do that with alternators, you could with the generators of old but they were DC voltage and put out low amounts at idle. An alternator puts out AC voltage which is converted to DC by the diodes in the alternator and it puts out almost full charge at idle. Different systems, different times.

[WyzrdX]

Well for future reference I will NOT be disconnecting anything before checking here first  W%


So I guess the new alt and new battery cut-off. I will check all the wires and replace any that look bad or corroded. And I will definitely make sure all connections are secure and clean. However I am still a bit confused. Will the isolator be ok or with the rust should I just replace it? They are fairly cheap so not a cost issue.

[Rickf1985]

You are replacing all the other expensive stuff so why not? One less thing to worry about. Just don't buy the cheapest one out there, the old adage of you get what you pay for applies now more than ever.

[WyzrdX]

Yeah I always go for the quality over price. And since this is our home, I will do my research just to make sure I get quality.

[1990HR]

OK since I had a few days to work on it I was able to get my Brother-in-Law out to assist. He works for a mobile RV repair company and he had a day off to help.


It appears it is the Alternator. There is a battery isolator which we pulled along with the alt. Both were tested at his shop and the isolator was good but alternator was bad. And I realized I need a new battery cut-off.


My question is should I replace the isolator as a precaution? It looks a bit old and like it has been through a flood. (ie. rust in places)

If you are questioning it and it does not cost an arm and a leg, I would replace it.
Better to replace it under controlled conditions like your driveway than on the side of the road.

[TerryH]

Ralph (HamRad Mobile) offered an intelligent, factual and knowledgeable reply to the OP's concerns.
I have often read Ralph's advice, comments and expert information here. I have also found them to be extremely helpful insofar as I am able to understand them.
I do wish I have the expert experience he does, but I do not. Regardless, he has helped me and others given his experience/knowledge.

Further, I rely on the font of expert advice that is freely offered on this site.
I would assume that members and guests that follow this site do so as well.

Rather than name names, you would be hard pressed to find the level of assistance on any RV site that you find here.

Mechanical
Structural
Transmission
Suspension
Appliances
Body
Tires
Travelling
etc....etc....etc...

We do on occasion add a bit of humor to a post or discussed subject. Please understand it is just that - a small injection of humor.

[Oz]

Very true!


Opinions are welcome from everyone.  Some are simple rules of thumb, such as, "When in doubt, throw it out." and, "If it isn't broke, don't fix it." which are as valid as any other advice since nearly all of us have used them to make our some of our decisions from time to time.  Other opinions are well formulated and expressed facts of knowledge and experience, backed with sound cause and effect reasoning based on technical principal.

If an opinion is a rule of thumb and no further technically backed and explained reasons are given for advice which is contrary to other information presented which is backed with technical explanation, then there is no reason to challenge such technically supported presentations with instigating interjections which amount to nothing more than trolling, which is what obviously has happened here and is against the forum conduct rules, as stated in the rules.


The posts have been edited and some removed to clean up this topic.