QuestionVan, welcome back from vacation! Hope it was enjoyable. We have read nearly every one of your posts in trying to figure out our CUCV blazer. It is still the original military setup with 24 v. starter and glow plugs.
The voltmeter on the dash reads a good 28 v. when the engine is running both at idle and when speeded up in neutral. When you put the transmission in drive, as soon as you touch the throttle the voltage drops to about 26v. maybe a little less. This causes some problems on the 12v. side with the FD radios installed in the vehicle. Also noticeable light dimming when this happens. We have traced just about every wire we could looking for a ground without result. No fuses are blowing, there is no evidence of anything going to ground anywhere. We had the driver's side alternator rebuilt. We have a second CUCV M1008 that we stole the alternator off and put on the passenger's side. Neither made any difference.
Any idea what might be causing the problem? It is particularly puzzling in that it only occurs when the transmission is in gear and the throttle is pressed. Not everytime, either, so it is intermittent.
Thanks in advance for any help.
Jim
AnswerHi Jim,
I believe it isn't a mysterious ground....I believe it is a poor ground.
Run a ground cable from the engine block to the frame, and a good ground from the block to the firewall.
You are probably grounding through "U"joints, shift linkage, etc.
The more grounds the better.
And the glow plugs are 12 volt, even though it might measure 24 at the solenoid when they are not engaged. You probably still have that big resistor block on the firewall behind the engine.
Van
