Glow plug relay

[Husker67]

I recently rebuilt my 6.2 due to some cylinder problems. The truck started perfectly prior to me removing it. Now I have no glow plug relay control and there is 24v to the input side and no voltage to the relay solenoid when I activate the push button. I am getting the wait light to illuminate when I use the push button. The truck wiring system was heavily modified when I purchased it but as I said, everything was working before I pulled the engine. I changed something but I cant find it. any ideas as to what may have happened?

 

[MAZ537]

I recently rebuilt my 6.2 due to some cylinder problems. The truck started perfectly prior to me removing it. Now I have no glow plug relay control and there is 24v to the input side and no voltage to the relay solenoid when I activate the push button. I am getting the wait light to illuminate when I use the push button. The truck wiring system was heavily modified when I purchased it but as I said, everything was working before I pulled the engine. I changed something but I cant find it. any ideas as to what may have happened?

I hope to have this already sorted out but sometimes it is better to switch back to stock glow plug setup as the wiring is not that hard to restore...

 

[Husker67]

I hope to have this already sorted out but sometimes it is better to switch back to stock glow plug setup as the wiring is not that hard to restore...

MAZ537, I haven't gotten this figured out yet. I now have it worse as there is no 12V in the cab at all. I can't find where I'm supposed to be getting the 12V from to the fuse block. The purple white to the starter relay has no power, the yellow wire to the ignition switch has no power, neither does any other connector on the fuse block. All of the after market 12V lights and radio have power but that comes direct from the battery. What am I missing?

 

[royalflush55]

Do you have 12 volt at the diamond on the front firewall? Sounds like fusible link is melted.

 

[lizzyfur]

Yeah I second the burnt fusible link. If you still have the stock wiring to the 12V block, then the wire you're looking for should be the 8 awg red one running across the top of the firewall from the negative terminal of the rear battery to the 12V distribution block. Check for continuity across that.

Also double check that everything on the engine harness got plugged back in properly and that there's no wires that got cut/pinched when the engine was reinstalled. If the fusible link got burned up then there's probably a short somewhere

 

[MarcusOReallyus]

Follow the basic troubleshooting tests. You have verified that you have 24v to the top of the relay, and nothing coming out. That's an excellent first step.

I also means you have NOT done the resistor bypass. Fine - don't mess with that for now, and don't let anybody talk you into messing with it now. You need it all working and you do NOT need any changes to confuse the picture.


Now see if you have 12v to one of the small terminals on the relay (small orange wire) when the key is on. If you do, ground the the other small terminal (blue wire) and see if you get 12v to the bottom big relay terminal (output to the GPs.)

If that test works, the problem is probably with your GP controller card.

If you don't have 12v to the orange wire, you probably fired a fuse or a fusible link.