CUCV no start.

[gjones]

My friends CUCV cranks great with new batteries, but won't fire at all. Voltage at glow plug was "O" with key on and "wait" light on. Anybody have any idea's on what could be the problem ?

 

[cpf240]

I'd start by checking the glow plug relay. Is it cycling when the wait light comes on? Usually a thunk can be heard. If it appears to be cycling, but no voltage on the glow plug side, check the input side of the relay. Also, the contacts in them can get carboned up and not pass voltage/current to the glow plugs. If it is not cycling, try grounding out the terminal with the blue wire on it. If it cycles then, there may be an issue with the glow plug controller card.

 

[cpf240]

Also, take a look at the Helpful Threads sticky in the CUCV forum. Start with this one: http://www.steelsoldiers.com/showthread.php?62477-GP-Module-Theory-of-Operation

 

[tim292stro]

Welcome to the site from California - Go Bucks! (and maybe all the way this year )

Yes, start with the plugs, then look at the fuel supply - the pink wire to the IP (Injector Pump) should have +12V at it with the key "on". If you pull the connector for it off with the key "on" you should hear a slight "click" as you re-attach it.

Do you run this truck often or is this the first time in a while?

 

[gjones]

He just bought it (on line auction). Did an oil change, air filter, and fuel filter. Bled the filter, re-attached the pink wire, but no start. That's when I checked the voltage at one of the glow plugs. (replaced the starter relay since I had read that they have a tendency to freeze up from setting long periods of time).

 

[gjones]

Where is the glow plug relay ?

 

[AECS]

Drivers side firewall, next to the 12v Buss block.

 

[patracy]

Also, take a look at the Helpful Threads sticky in the CUCV forum. Start with this one: http://www.steelsoldiers.com/showthread.php?62477-GP-Module-Theory-of-Operation

And to add to that, gjones, take a look at the TM section. They're very helpful when working on vehicles.

http://www.steelsoldiers.com/forumdisplay.php?114-CUCV-TMs

The -20's get in depth with the vehicle systems.

http://www.steelsoldiers.com/showthread.php?77609-TM-s-for-the-CUCV

 

[Skinny]

I will make two statements here for anyone reading this now or in the future will which benefit all that have a newly purchased unknown rig.

1. Do not attempt to start these rigs until you have done the proper repairs/upgrades like replacing all the GP's, resistor bypass, starter solenoid fix, etc.
2. Do not attempt to start these rigs until you have done the proper research on how the starting/charging/fuel systems work.

You can risk damaging something or will spend a lot of time pulling your hair out trying to make it work. You just have to bite the bullet and spend some money out of the gate along with the time to understand normal operation. I didn't touch my new ambulance and I already through some bucks at all of those repairs. Then you can do a type of operational check on each system before giving it the final OK to run.

If you know these principles you can take shortcuts like using either or jumping a starter motor just to get it moving but unless you have confidence...something usually goes boom!

 

[Tinstar]

I will make two statements here for anyone reading this now or in the future will which benefit all that have a newly purchased unknown rig.

1. Do not attempt to start these rigs until you have done the proper repairs/upgrades like replacing all the GP's, resistor bypass, starter solenoid fix, etc.
2. Do not attempt to start these rigs until you have done the proper research on how the starting/charging/fuel systems work.

You can risk damaging something or will spend a lot of time pulling your hair out trying to make it work. You just have to bite the bullet and spend some money out of the gate along with the time to understand normal operation. I didn't touch my new ambulance and I already through some bucks at all of those repairs. Then you can do a type of operational check on each system before giving it the final OK to run.

If you know these principles you can take shortcuts like using either or jumping a starter motor just to get it moving but unless you have confidence...something usually goes boom!

+1

i didn't attempt start (M1008A1) for a month while things were replaced and fixed and TM's poured over.

Others wth way more knowledge on CUCV's will help you with the issue

One of the many things that was and is very helpful are the old posts.
Do a search or just start reading old post like I did
Your not the first one with that problem

good luck

 

[gjones]

Thanks guys.

 

[gjones]

It was the relay. Bought 1 at O'Reilley auto parts (about $34). Fired right up after "Wait" light went out.

 

[M1008BOV]

Same issue I'm having. My truck sits in the garage all winter (don't want it out in the salt/weather). Ran great when I parked it, but now it's been a couple of months and the glow plugs aren't cycling like they usually do. My wait light comes on, but I never hear the relay cycle and the light doesn't turn off. I've been reading helpful threads here and doing the diagnostic procedure in the -20. I have no juice on the orange side of the relay. I've tested the resistance of all the glow plugs and they were all in spec. The manual says to unhook them all before trying to ground out the blue wire. Is there a reason for this? I think I just have a bad relay, but want to rule out the card also.

Thanks-
Jason

 

[tim292stro]

Measure both sides of the relay coil to narrow down the problem. No power on the orange side and power on the Red side just means the relay isn't actuating. When you turn on the ignition (On, not start), there should be power to the coil of the relay. If the GP controller is trying to turn on the relay, the pink/black wire should be +12V and the light-blue wire should be Ground (0V). If the GP controller is not trying to turn on the relay, both wires should be at +12V (the GP card "pulls down" one leg of the GP relay to ground to turn it on).

 

[M1008BOV]

Thanks, I just tested that. As soon as I grounded out that light blue wire the relay started to cycle. After that it cycled fine on it's own, but I did notice a bit of flickering in the lights on the dash, so I'll definitely be getting a replacement (after I find the part#). She fired right up!

 

[M1008BOV]

Ok, so the S603 relay equates to the Napa ST80. I saw the part number ST85 also on here. According to the Napa website, the ST80 uses silver alloy contacts and the ST85 uses copper contacts. Other than that they are identical. Price difference is only a couple of dollars, which would be best for this application? I always understood copper to be superior.

 

[cucvrus]

I have been using snow plow relays on my stock CUCV's since GM discontinued the original ones. i am thinking like $15. They seem to last a long time. i have the same one on my Crown of Thorns for 10 years. That's pretty long.