1995 6.5 no start No glow plug light

[N9Phil]

Here we go again. The diesel has been starting and running fine and when I got home yesterday I shut it off and no indication of any problem. This morning when I went to start it up I noticed that the glow plug light did not come on. Well when this happens it will not start. This happened a few years ago and I ended up changing the chip in the computer. However this time when I put the paper clip in to read the codes I was receiving a 12 so I assume that there is another problem other than the computer. I tried another FSD and another chip and there was no change. I am now open to any suggestions as to what to try. I have been hunting for the wire diagram of the glow plug and starting requirements and have not found it.

[N9Phil]

I managed to get it going again. After switching computers and chips back and forth I started to receive a 29 code. I connected my tech 1 and erased the codes then I was back to a code 12. Then with the key on I shorted the glow coil relay for about 7 or 8 seconds and the glow coil light lit real faint. The beast started so I let it run for 15 minutes. After shutting down the glow coil light is working again and it starts right up. At this stage in the game I am thinking a glow plug relay or wiring.

[Dvldog8793]

Howdy
It sounds like the glow circuit. I would check the relay and associated wire connections first. I believe the light on the dash is a direct connection to the glow circuit. In other words the light will be dim if it is not getting good voltage to the glow circuit. A relay can be a fickle thing and could have sporadic symptoms for a long time before coming to a complete failure. Also a poor signal connection can be giving unreliable performance.

I had a very similar problem with my 1996. pulled the relay, benched it and it failed 8 out of ten cycles and then started working again and I couldn't get it to fail. Put in a new one and cleaned all the connections good and its been gold ever since.

Good Luck!

[N9Phil]

New relay due here Tuesday

Semper Fi Dvldog8793

[Aftermath]

I had a similar problem a few years ago. Turned out to be a broken wire at the Glow Plug Controller.

[More Power]

It sounds like the glow circuit. I would check the relay and associated wire connections first. I believe the light on the dash is a direct connection to the glow circuit. In other words the light will be dim if it is not getting good voltage to the glow circuit.

That's correct (sounds like a wiring or glow relay problem).

For anyone who has a "no glow" cold starting problem and need to move/start/drive the vehicle... These engines, when healthy, need to be at ~80 F or higher to start without glow. You can start the engine without glow plugs a couple of ways, but the safest is to simply use the engine block heater for a couple of hours to raise the engine temperature to above 80 degrees.

Ether (starting fluid) can be used as well, but it presents considerable risk if not done correctly. The best way... wisp in a few light sprays while someone is cranking the engine. The idea is to use only just enough to get the engine to fire - no more than that.