Glow Plug System Problem

[Brogman]

Just finished converting to 12 Volt with new passenger side alternator and two batteries connected together. Put in new glow plugs AC60's and new NAPA Glow plug relay. Also did the Doghead starter relay replacement. Followed the instructions exactly. New starter turns over better than the old 24 volt, but the glow plug light and relay don't work. I put in a new volt meter too but it doesn't work, checked red wire no power. There is power to the glow plug relay from the bus on the fire wall wired direct per instructions. Every thing else seems to work. Glow plug system worked before this.

 

[rsh4364]

I cant help you but if you list more info.someone should be able to.Did you use rosscomon 12v conversion directions?What part#s did you use forGP solenoid,New volt meter,and new alternator? Pictures might help also.Good Luck.

 

[Mg84648]

Check to make sure your relay is insulated from the firewall. If its touching it will be grounded and not function properly.
This happened to me a few months ago, my insulators for the relay were worn out and grounded my relay.
Also check your 2 IGN fuses on the lower left corner of your fuse box.
Just somethings to check.

 

[doghead]

Check to make sure your relay is insulated from the firewall. If its touching it will be grounded and not function properly.
This happened to me a few months ago, my insulators for the relay were worn out and grounded my relay.
Also check your 2 IGN fuses on the lower left corner of your fuse box.
Just somethings to check.

If you have the proper relay, the coil is isolated from the chassis.

 

[Brogman]

Yes, Rosscommon conversion was done. I was very careful to follow the instructions exactly as described. One Alternator on Passenger side and 2 batteries. Wilson 90014277 27si 100 amp alternator, NAPA ST85 GP relay, AC60G glow plugs, Doghead starter relay mod done. I replaced the dead stock volt meter with a EQUUS 7268 volt meter. The light works in the new meter but no power with key on to the meter itself(connected the light gray wire to meter input and black wire to meter ground that were connected to the old meter).

Here is where I think one of my problems is. I found a new wire to the starter solenoid was spliced into the large purple wire that went to the GP controller card holder(its the last wire on one side of the controller holder). I tried to fix this during the convertion but found the original wire from the engine harness to the starter solenoid was cut and about 5" was still in the black wire protector teeing off the engine harness on the passenger side. Additionally I found the same color purple wire in the middle of the engine harness along the firewall was cut and the wires were just twisted together. I traced the twisted together wires thinking that they were part of the solenoid wire and found that it went to a smaller plug under the fuel filter. I was looking at the diode post and think the twisted wires are where the water in fuel diode was. Who ever did this must have thought it was the starter solenoid wire. Since the system worked before the Rosscommon conversion I left it alone at that point. I didn't know that the purple wire under the dash that they spliced into came from the GP card holder. I thought it came from the wire to the Doghead modified starter relay.

 

[Brogman]

I am thinking that I can hook the wire to the starter solenoid to the Doghead starter relay and reconnect the purple wire that the direct wire to the starter solenoid is spliced into back to the GP card holder.
I think that the people who cut the wire to the GP card found the Ignition signal to the GP's when you are starting and thought that was the wire from the starter relay. Maybe the starter relay was bad and they got the wrong wire. I will trace the original purple wire to the starter solenoid and see if it goes to the Doghead relay. I will reconnect the purple ignition wire to the glow plug card.

But I don't think this will fix the no power to the GP controller.

 

[Brogman]

I pulled the purple starter solenoid wire that went to the starter before they wired in a direct wire from the GP card purple ignition wire. I pulled it out all the way to the harness connector block on the fire wall. I connected the wire in the engine compartment to the positive on the battery and got a good test light so power does go to the starter relay from the old purple solenoid wirer​. I then reconnected the wire to the doghead relay and turned the key to start to see if it would click and give power to the purple wire. I had a previous problem when starting, I had to lift up on the shift lever to get the starter to go when the trucks GP and starter worked before the rosscommon conversion. During todays test I had to do the same thing to get the relay to click. The relay barely clicked intermittently. So I replaced the start switch under the column. Now it appears to work without lifting the shift lever but the relay doesn't click. I seem to have no power to the red wire that should supply power through the starter relay to the purple solenoid wire. I don't see any sign of hot or melted wires anywhere so I am at a loss as to what to do to get power to my Starter and glow plug system. I did reconnect the glow plug card purple ignition wire. One more thing how did the 12 volt GP ignition work the 24 volt starter solenoid? I guess 12 volts was enough to make it work?
Any help would be greatly appreciated.

 

[Brogman]

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[Brogman]

I made changes to the post above to reflect some changes in the trouble shooting info. So I have a starter problem using the key and start relay and a glow plug system that worked but now doesn't. I replaced the back up light switch when I first got the truck. The back up lights and the rest of the lights except the under dash light under the ash tray do work as they should after the rosscommon conversion. Is the back up light switch also a neutral safety switch, I think I read that there is no neutral safety switch. My switch only has one plug that has 2 blue wires on one connector and a single pea green wire to the other connector in the plug. My fuses all seem to be good as well.

 

[Brogman]

Found the fusible link was broken that connected the red wire to the now 12 volt positive bus and goes to the starter relay. I now have power to the red wire to the starter relay. Will be going to NAPA for fusible link replacements I found in the sticky section. No power to the Volt meter terminal on the fuse box and no power to the 3 ignition terminals on the fuse box with the key on. Could another fusible link be the cause of these issues? So now I have found and fixed the purple wire from the starter relay to the starter solenoid and the red power line to the starter relay. Since my Diagnostic system harness is gone I didn't reconnect the Feed to diagnostic System STE/ICE to the positive power bus. If that will cause a problem please let me know. If the fusible link repair doesn't fix some of the other problems I guess I will tackle the Ignition yellow wire that splices into the 3 purple/white wires to the ignition switch/GP card/water in fuel sensor. Turning the key on still doesn't activate the GP system and turning the key to start doesn't activate the starter relay. Man What a mess I have found myself in.

 

[Brogman]

Key/ignition switch on:







Key/ignition switch to start:






GP card wires after reconnected purple wire:~

 

[Brogman]

Does anyone know what this light blue wire coming from the GP Harness is supposed to connect to and do? The truck came like this.

 

[Brogman]

Some pictures of the wiring as it is now:

 

[Brogman]

Could I have a no power to the Yellow wire from the start switch to the 3 purple/white wires? Trying to figure out from the wiring diagram how the GP system gets power and why there isn't any now. I watched the video and read the sticky info. I have no power to the 24 volt (now 12 volt) terminal on the fuse box and no power with the key on to the 3 IGN terminals on the fuse box.

 

[Brogman]

This is just a junction for the 12 volt power cables, there is nothing behind it that connect to the bolts on the front???? The reason I ask is I am going to replace the fusible links and one of the connectors in the picture connects to both post. Since I converted it to 12 volts can I put a larger ring on the small wire on the left and put it on the large bolt so all three wires will be together on the large post.

 

[cucvrus]

Does anyone know what this light blue wire coming from the GP Harness is supposed to connect to and do? The truck came like this.






View attachment 592286View attachment 592286

That light blue wire goes to the fuel pump on the M1010 rear heater. It is in every CUCV even thou it is only used in the M1010 and the arctic kit.

 

[Brogman]

Thank you so much for answering my question "cucvrus" one more thing I don't have to mess with. This has become a struggle but I will plow on.

 

[Brogman]

I replaced the 16ga fusible link wire on the red wire to the starter relay and the 2 wires on the 12 volt harness block on the fire wall. I have power to the Dog head starter relay red wire and good continuity on the purple wire from the dog head relay to the starter solenoid.

I have power to the fuse box formerly 24 volt hot spot on the fuse box and power to the 3 ignition test connections on the fuse box.

How do I check the glow plug card for power with the key on? The dog head starter relay doesn't work when the key is turned to start but does work if 12 volts is applied to the Purple /white wire terminal on the relay.

Should I cut the wiring harness cover and find the yellow wire and the 3 purple/white wires to see if they have power?

Any suggestions on what to try next?
~~~~~~
Are the 2 wires from the 12 volt harness the ones that power the truck in the cab? They are in the third picture with the red wire tie holding them together for identification. The purple wire in the picture is the one to the starter solenoid from the Dog head relay under the dash.
The other red wire with the back tape and 2 red wire ties is the one from the positive bus on the fire wall to the Dog head relay under the dash.

 

[Brogman]

Made a mistake here.

 

[Brogman]

Got my starter problem fixed. I pulled the new start switch out and found it had power and when manually selecting start the Dog Head relay worked. I did open up the wiring harness to check the wires to the start switch and other wires on the steering column. I am guessing the old start switch was the original problem that had them splice the wrong wires and then running a new wire directly to the starter. I must have staged the NEW start switch wrong when I put it in. I did it right this time and got the starter relay to work so now the starter works. But, I still have no glow plug operation. Any one have an Idea of how to go about fixing the glow plug system.