How are the batteries hooked-up & no spark problem

[MSN Member]

From: road hog
Sent: 11/29/2001

HELP PLEASE, I have purchased a 1971 Winnebago with a dodge 413c.i. engine that I towed home. my problem is that most of the battery cables are missing, I have one ground cable hanging in the battery compartment Thats It. can someone give me an idea of how & where the rest of the cables hook up to the batteries and the solenoid in the battery compartment ? also  there is a long black wire hanging that goes all the way to the back of the motorhome, I'm not sure if that has something to do with the generator or not.
any help will be Greatly Appreciated, Thanks,   Road Hog

[MSN Member]

From: Colin
Sent: 11/30/2001

I'm no expert, but I'll try to give you an overview.  The system is divided into one power source for the chassis (engine, headlights, dash etc.) and one power source for the coach (lights, water pump, furnace, generator starter etc.).  I have two batteries for each power source.  I wire each pair of batteries in parallel.  I use automotive batteries for the chassis and deep storage batteries for the coach. You have to be careful that one doesn't drain the other, best to keep them as fully charged as possible.
The positive cables from each battery pair are attached to the separate sides of the solenoid in the battery compartment.  A primary wire runs from the connection on the center of the solenoid to the battery switch on the dash.  Check it and make sure you hear a click when you push the switch.  Also run a positive cable from the chassis side of the solenoid to the starter solenoid.  Attach the positive cable from the rear of the coach to the coach side of the battery solenoid.
Both sets of batteries are grounded to the frame.  I would advise establishing a ground directly on the frame.  The ground on the side of the battery compartment doesn't make as good a connection.
The wire that you found running to the rear could be the positive coach cable, but it might also be a remnant of a trailer connection.  Trace its path to be sure.  I hope this helps.  I would need more specifics if you are having a particular problem.  Some of the more experienced members could also help.

Colin

[MSN Member]

From: road hog
Sent: 12/3/2001

Thanks Colin,
You have cured my problem with the dual battery cable hook-up, all lights work, generator works,converter works, Now one more problem, the starter turns the engine over with no problem but I'm not getting any spark from the coil, I have replaced the points & condenser and also a new coil and have the pos.& neg.wires to the coil in their proper position but when I put the coil wire near the engine block I get very little yellow spark sometimes no spark at all. Could it be that I have a bad ground on the solenoid in the battery compartment ? Thanks for all of you help

[MSN Member]

From: Colin
Sent: 12/4/2001

As long as the connection between the positive cable from the battery and the positive cable to the starter solenoid at the chassis side of the battery solenoid is solid, the actual connection of the battery solenoid to the wall won't make any difference. Are you sure of the spot where you are trying the coil wire?  Dirt and rust on the block may be affecting the spark that you see.

I would first check the battery, then check the main ground.  Again, I put in a new ground on the frame rail, and I actually ran a ground cable from the engine to the new ground and ran several other ground wires to it too.  I probably went a little overboard, but it really made a difference.

On the positive side, check the wiring and the connections from the battery all the way to the coil.  If you have a voltmeter, check the voltage at each step along the way.  A sudden drop should help you locate the problem.  Also check the negative wire going back from the coil.  If you have any doubts about the starter solenoid, the voltage regulator, the ballast resister or the coil wire,  I would replace them.  The parts aren't that expensive.  If any of the wiring looks questionable, replace it.  Use at least 12 gauge.  Hopefully one of these steps should solve the problem.  Does anyone else have any other ideas?

[MSN Member]

From: road hog
Sent: 12/4/2001

Thanks again for you help Colin,
But I found the problem with no spark from the coil one of the ends of the coil wire itself was burnt off, I replaced the coil wire and everything is fine, It Runs Great.
Just waiting to get the insurance & plates so I can take off down the road.
Maybe We'll meet up someday in our travels.
THANKS AGAIN FOR ALL OF YOUR HELP IT'S GREATLY APPRECIATED....ROAD HOG