First Post- Smoked under hood-electrical issues- CUCV pickup

[mtperkins]

Hello Folks,

So my wipers were not working last winter and i found a burned out fuse holder. While i was under the dash i found a accessory wire unhooked that i thought went into the fuse box. Well i plugged that in and i ended up with smoke under the hood. Unhooked it fast. Then my glow plug light would stay on while running.

Parked the truck for months before the glow plugs burned up.

Removed shorted out voltage drop that was feeding Glow Plugs 24v. Replaced the GP's.

Replaced GP relay. Wait to start light still stays on. I would unhook power to GP relay after i got the truck running.

Then the batteries would be dead. Found 5 volt short at the 24 suppressor. Removed that.

Next i hooked the GP relay back up and then tried to hook the batteries back up. SMOKE!!!! The blue wires (fuse link) at the 2 stud firewall engine terminal block melted. ( insulation only it seems)

I quickly unhooked the bat cables. unhooked the GP relay from this. Then hooked the batteries back up. Everything was fine. Hooked up GP relay. Used GP to start the truck. It ran and my stupid wait to start light was out finally.

HOWEVER!!! Now i have a 10 volt draw on the first battery.

I unhooked the GP relay and alternators. Still 10v draw.

Bash me for trying idc. But im just frustrated. What did i burn up now?

Truck is now named Smokey...


Matt

1986 CUCV

 

[stuinnh]

Hi
GP's are 12v. There is a resister that drops voltage from 24v to 12v to supply GP's. It is mounted on firewall behind engine. I bypassed the GP relay and put a button on the dash wired to solenoid and fired them manually. 10-15 seconds on button and it will fire right up. I moved power supply wire to feed from connection block on firewall 12v, and removed resister. Much better feed. If it is hard starting in when engine cold it will be the fuel pressure switch (only in military trucks) located in Stanadyne filter base behind filter. The round plastic switch cracks and sometimes leaks gas too. It will feel as if gas is is flooding or draining back to tank. I learned hard way too. Tried check valve, rebuilt injector pump, new GPs, GP relay, new military fuel filter base, etc. Even snapped all the glow plugs from over tightening . Had to have them all drilled out.
Hope all works out. Fuel pressure switch problem is VERY common when truck won't start in morning.

Hello Folks,

So my wipers were not working last winter and i found a burned out fuse holder. While i was under the dash i found a accessory wire unhooked that i thought went into the fuse box. Well i plugged that in and i ended up with smoke under the hood. Unhooked it fast. Then my glow plug light would stay on while running.

Parked the truck for months before the glow plugs burned up.

Removed shorted out voltage drop that was feeding Glow Plugs 24v. Replaced the GP's.

Replaced GP relay. Wait to start light still stays on. I would unhook power to GP relay after i got the truck running.

Then the batteries would be dead. Found 5 volt short at the 24 suppressor. Removed that.

Next i hooked the GP relay back up and then tried to hook the batteries back up. SMOKE!!!! The blue wires (fuse link) at the 2 stud firewall engine terminal block melted. ( insulation only it seems)

I quickly unhooked the bat cables. unhooked the GP relay from this. Then hooked the batteries back up. Everything was fine. Hooked up GP relay. Used GP to start the truck. It ran and my stupid wait to start light was out finally.

HOWEVER!!! Now i have a 10 volt draw on the first battery.

I unhooked the GP relay and alternators. Still 10v draw.

Bash me for trying idc. But im just frustrated. What did i burn up now?

Truck is now named Smokey...


Matt

1986 CUCV

 

[mtperkins]

Thanks for the reply.

Truck runs now and runs really good, just has a huge battery draw.. I will keep searching.... Process of elimination.