GP Controller normal operation?

[idM1028]

As if I didn't have enough electrical issures to deal with. . . not sure if this is normal or not. Any help would be appreciated. When I go to start the truck up, I can hear the GP relay energizing and clicking (and according to the voltmeter, sucking a lot of juice while its doing it.) It'll probably click on and off about 10+ times before the wait light goes out. What's wierd is it will usually continue to click on and off several more times once the truck is started. After a minute or so it stops. The truck never used to do this. I'm thinking the GP controller might be going out and I now they're a pain when they do. It has been pretty hot around here lately if that helps at all.

 

[top_prop]

No expert here... but why not just bypass it and add a simple button... this is how my 87 suburban with a 6.2 is... and its probably how my CUCV will end up..

 

[idM1028]

Could be worth a shot. When I was first trying to diagnose the problem, I noticed a blue and white sticker by the GP relay that said something to the effect of "Do not bypass this relay with a jumper. Glow plug damage may result." Not sure if it would be the same thing with the GP controller or not.

 

[Warthog]

Why not follow the TM and diagnose the system before you start bypassing it?

Have you followed the sticky in the CUCV forum for the Operation of the GP system?

http://www.steelsoldiers.com/cucv/62477-gp-module-theory-operation.html

Installing a one wire manual bypass isn't a bad idea for an emergency backup.

The GP system works preaty well when all the contacts and clean, GPs are not burnt out and the batteries are good.

 

[idM1028]

Wouldn't suprise me if its the batteries. GEN 1 has gone bad (again) and is slowly draining my front battery. And yes, I've already tried checking for shorts and I spent most of yesterday spraying down every electrical connection I could find and get my hands on with electrical cleaner.

 

[mistaken1]

What I noticed in my limited experience was that when my stock system started cycling the glow plugs on and off in fairly quick succession and the wait light took longer and longer to go off was because my glow plugs were failing. I was surprised at how quickly they all burnt out (electrically open) once this pattern started.

Warthog is right. Follow the manual to find out what is wrong then fix it.

http://www.steelsoldiers.com/cucv/67999-download-cucv-tms-here-where-download-cucv-tms.html

 

[antennaclimber]

Possible problems are;
1. One or more of your GP's are open.
2. The system votage is higher than normal.

It sounds as if the GP module is functioning properly and that you have a few bad (open) glow plugs.

Is the GP system the stock 24 volt system or has the dropping resistor been bypassed?

 

[1stSarge]

Agree with Warthog, Mistaken and antennaclimber. It appears from your description that the controller is doing what it is supposed to do. If a glow plug is failing, the voltage is higher on the rest of the plugs. The controller senses this and begins cycling the relay on and off in an attempt to deliver an “average” voltage that is around 12 volts.

Go through the system, but start with the plugs. Measure the resistance of each one to ground - making sure they are tight and undamaged. They should read about 1-3 Ohms each.

 

[idM1028]

OK, thanks guys. The entire electrical system is stock other than the stuff I've fixed (which has been a lot) or the small stuff I've added (pretty much just a cigarette lighter off an open 12V plug in the fusebox and license plate lights spliced into the running lights) Any recommendations on new glow plugs? Something fairly heavy duty would be nice. . . these things are gonna to have to be putting up with midwest winters pretty soon here.

 

[top_prop]

Civie glow plugs with a great reputation: AC60G just besure to do a 12v bypass with them...