Hello all, I have a '81 Ramcharger 318 4x4,
been very reliable up until now, i thought I knew enough to troubleshoot the problem it's having, although to no provail,
Problem--> starts up good as usual but after running 20-30 minutes it shuts off, I can try restarting it and it will fire right up but then when I release the key it cuts off, I can rstart again and hold the key to start possion for a few secounds longer and the engine will stay running, but as soon as release it again it will cut off,
Things I have replaced---->
Ballast resistor,.. used change out 3 times
Relay............... New
Voltage regulator,.. New
Electronic module,. New
Coil & condenser,.. used changed out 2 times
.............................................
the coil is very hot when the engine cuts off I can let it set cool for an hour and it will start back up and run again for another 20-30 minuts,should I re-locate the coil off of the engine to up onto the firewall? would this help to keep the coil cooler?
the engine has never been ran hot.....
Note: when i changed out the V-regulator & module the wax had been melted completely from the back of both, running down the firewall, is this indication of something more serious? and should I be looking elsewhere as to the problem?
Here are the parts I replaced and example of condition I found them in...

Big thanks to all who can help..

ign switch. What is your charging voltage and are you using the std 4 prong ballast

I can remember something similar to this happening to my '78 power wagon years ago,
although I could run a wire from the starter relay/solenoid to the + side of coil and it would stay running, then I knew to replace the ballast, however not so easy fix with problem the Ramchrger is having, The RC has electronic dist. Not points as the PowerWagon had,
..... I had hope it not be the ignition switch and if even so? why only after 20-30 minutes should Ignition switch stop working?.
but I suppose that is all is left, there is one other part that I didn't change, I am not sure of its purpose?
looks like a small ballast sets along side of the coil & condiser, could this cause a problem as well? here is a picture of this part.

Is the battery boiling over?

I would say either you have a high voltage charging issue or a BAD underhood heat issue.

That thing in the above pic is an electric choke timer/controller and shouldn't be your problem. I've seen pick up coils in the distributor go bad and quit when hot and then restart after they cool. May be something to check. But it does sound like you are loosing power on your run circuit just like when the ballast goes bad?

I'd check for power at the ballast with the key in the on position. If there is none work your way back to the switch, paying close attention to the bulk head connector and the connectors at the steering column. Had a friend with a Duster awhile back it would just quit and wouldn't start. He could reach under the dash and move the connectors at the steering column and it would start. They loosen up over time for some reason.

Check the voltage to the coil with the key in the run position. It should be around 9v.

around 8-9 voltz at + side of the coil. and 12voltz at the ballast, I pulled the dist cap off today and fount the coil wire was stuck into the cap, a little force pulled the end off the wire, so I wound up changing the rotor Button and cap, BTW this dist. has dual pickups in it, how would one tell if one of them is bad leaving the other weak, again today after changing coil wire cap and rotor, it fired up and ran for 20 minutes and killed dead again, I had even moved coil awy from the heat off the engine, mounting it up on firewall and coil was still red hot to touch after running 20 minutes, I vaguely remember back in the 70's having to put bag of ice onto the coil of my old charger to cool it down so I could limp back home, changed the coil very next day it worked fine,.... I'm not sure why my ephassis is on the coil. its probably something to do with the switch? only I cant see it shutting off after running for 20 minutes or so, if it didn't start at all I could see it possibly being the ignition switch, I looked under the dash for any loose connections or meltd wires but found no bad signs, fuse box looks good,bulkhead looks good,
any other idea's?

thanks so far

If you have dual pick up coils it could be one of them bad as it seems one is for start and one for run mode. You can check them with an ohm meter where they plug in but I'm not sure what the range is for a good one. Maybe in the archives or maybe someone else knows and will chime in.

I reread your OP & I would pull the 2 leads off the ballast & check it's ohms, check your charging voltage at fast idle 1st with accessories off then w them on and w some jumper wires move the coil away from the eng as in front of the radiator for a day w some long jumper wires & see if that fixes it.

Day 3 on the trouble shooting electrical gremlin,
I went ahead a removed the Ign. switch and found the terminal with the Blue wire had in fact been heated and was stuck to leed connector, actually the plug fell apart while pulling on it, seems as though something has got hot enough to heat the connection but not hot enough to melt any wires,
so I guess i'm off to the parts store for a Ign switch now,........-----> OK got the switch actually went to the salvage yard and gotwhat I hope is a good one so I could get a good wiring connector as well. I changed it out and started-r-up runs 20 minutes and shuts off once again, it's like clock work,runs for 20 minutes every time before shutting down, why not 5 10 or 40 minutes? something is evedentially getting to a certain temp. and shutting down in that instant, I mean it kills all at once. and it always starts right back up in with key in the starting position although when releae back to run pasition is when it kills,
as I may have mention before I can however Hold the key in start position and it will run forever but so will the starter, the other od thing is the RC will have to set for 2-3 hours before it will run on its own again, for the 20 minutes it runs that is! .....looks like this is going to be a 4 day chapter

Did you fix the terminal that went on that burned up ignition switch?

Here ya go:

On the start/run relay:

I'd say your run pickup coil is going bad. It's running off the start pickup coil when you hold the key in the start position. Your best bet would be to let it run it's 20 minutes until it quits. Then check for power at the coil or ballast resistor. If you still have power there and it still won't run check the pickup coils with an ohm meter. The Haynes book says they should be the same and be between 150-900 ohms. Also while you have your meter handy ground one lead and check for a ground at each pickup coil lead. There should be no continuity. Good luck!

Hi again folks, Ok here is what its come down to,
after replacing the start/run relay, and was no help, I started messing with the wire connectors around on the distributor, I found that if I connect the 3 wire plug from the harness to the run side of the pick-up coil it will crank and stay running indefinitely, but this 3 wire plug is supposed be pluged into the start side coil,
what looks to be is a jumper wire coming from one plug to the other these are brown wires,the yellow wire is the one I am using to jump over but this lookslike it may be only the grounds,,,
are these 2 plugs independently fed from 2 resources? or can I simply make a splice into the start side connection and jump to run side pick-up?
with running only the run side it tends to run weakly with a slite bad idle, should both sides alays have power to pick-up coils? or is whats happening is the start side cannot keep up with enough volts to run the ignition because the run coil is not being fed power to assist? would this also cause the ignition coil to be extra hot perhaps causing system to shut down?
there still; seems to be a lot of variables....
am I heading in the right direction with resolving the problem?
Thanks!