1978 chevy van 30 motorhome


Old 07-03-04, 08:44 PM
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1978 chevy van 30 motorhome

When the summer time tempratures are in the 90's and the vehical is run for a long distance ( we tow) but it does this either way , you pull into a filling station or a rest stop and shut off the ignition and then try to start again it will not start .. the relay that picks up the solenoid does not operate and will not untill the vehicle has cooled down for 1/2 to 1 hour. then it starts and runs untill the the next stop. can you tell me where this temprature switch is located so i can bypass it and be on my way again !!! filling station operators don't appreciate us tying up a whole row of gas pumps especially on a busy day.
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Old 07-05-04, 08:58 AM
Join Date: Apr 2002
Location: Pittsburgh,Pa
Posts: 2,417
Sounds like a bad starter or battery cables to me that's where I would be looking first.
Old 07-06-04, 03:14 PM
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tried that, anyone else

I've already done that Davo. The problem is not the cables or the starter. The problem is in the control circuitry. Anyone who has worked on one of these have any ideas?
Old 07-06-04, 08:07 PM
Join Date: Dec 2001
Posts: 2,538
if you are saying the vehicle will not crank over it does sound like a starter problem but could be an ignition switch or nuetral safety switch problem but there is no temp controlled switch anywhere in the starter circuit.
starters will commonly get hot on long trips and usually requires starter replacement or even a heat shield.
Old 07-06-04, 11:05 PM
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neutral safety switch is probably the problem

bejay, I think you are on the nose with the neutral safety switch being the problem. I had to bypass one on another chevy van 30 that had the same symptoms. The bypass solved the problem.
Do do you know what the wiring color for the neutral safety switch is on the 78 chevy? I'm going to put a temporary bypass switch around it. So that if it let's me down, I can restart it and move to safety while it cools down. It's down right dangerous to be in the approach to a gas station with your back end in a traffic lane.
Thanks for the confirmation of my suspicions that the safety switch may be at the heart of the matter.

Last edited by cavebear28; 07-06-04 at 11:07 PM. Reason: spelling is wrong
Old 07-07-04, 06:32 AM
Join Date: Dec 2001
Posts: 2,538
If you havent verified that the starter is not getting power at the small terminal when the vehicle is acting up you should confirm this with a test light before bypassing the nuetral safety switch.
do not know the wire colors would need to find a wiring diagram or you could likely figure it out by using a test light and ohm meter.
one other possible cause would be if the small terminal wire was running to close to the exhuast it can short out and cause this problem.
Old 08-05-04, 08:05 PM
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Hot starter solenoid fix "garanteed to work"

I had this exact problem on the same motorhome you have and followed these directions and to this day the problem has never happened again

A lot of us at some time or another have experienced problems with the solenoid on a Chevrolet starter not working when it gets hot. This is caused by the high amperage required to engage the Chevy solenoid. The problem is compounded by headers and high ambient temperatures. I like to head off these problems by installing my own hot start kit from the get go when building a rod. Many kits are available to do this in the price range of $35-$75. For the price of a $15 Ford remote mounted starter solenoid you can do the same thing yourself.

Mount the Ford starter solenoid in a convenient location between the battery and the starter. I located the one on my 38 Chevy coupe under the floorboard on the passenger side since I have the battery mounted in the rear of the passenger side fender. That way I can use the shortest battery cables possible and the extra solenoid is out of view.

Attach the + battery cable (along with any other wires that would normally be attached to the large post of the Chevy starter) to the large terminal on the Ford solenoid which is next to the start switch terminal.

Remove the wire from the small starter switch terminal on the Chevy starter solenoid and attach it to the corresponding starter switch terminal (usually labeled 'S') on the Ford solenoid. Next, a jumper needs to be placed from the large battery cable terminal to the small starter switch terminal on the Chevy starter solenoid. I simply flatten out a short piece of 3/8" copper tubing and drill a 7/16" and a 3/16" hole in it to serve this purpose.

Finally, purchase a battery cable with a 3/8" lug on each end and attach it from the other large terminal of the Ford solenoid to the large terminal on the Chevy Solenoid where you removed the original battery cable and attached the jumper. If you have an original point type distributor, then you can attach the 16 ga. wire that goes to the coil terminal on the Ford solenoid.

You can purchase a Ford solenoid with this extra terminal if you plan on doing this or this wire can be simply attached to the large terminal that goes to the starter. Don't attach it to the battery side or the engine will continue to run with the switch turned off! Having the start circuit wired in this fashion can serve several purposes other than just eliminating a hot start problem.

You now have a place away from the heat of the starter to attach power taps such as alternator leads, amplifiers, fan relays, etc. You also have a more convenient location to attach a remote starter switch for bumping over the engine. Also, a 12 ga. wire is no longer needed in the start switch circuit. Other pluses are that the Ford solenoid takes much less amperage to engage than the Chevy solenoid (which can burn out the neutral safety switches of most aftermarket shifters) and the cable on the Chevy solenoid is no longer HOT at all times eliminating the need to remove the battery cable to replace the starter. Although this is a good idea anyway.

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