Wait light suddenly stopped working

[n8roro]

The truck has been driving great and has the stock glow plug system. This evening the wait light did not come on and it was hard to start. Normally if the engine is warm enough for no wait light it fires up instantly and it did not do that which is why I'm wondering if there is something off with the glow plug circuit. When I got home I did some investigating and I have 24V at the glow plug solenoid with the key on but no power at the glow plugs. The voltage is on the solenoid is 24V incoming Small red wire=11.9 Blue wire=11.9 0V= Orange wires to glow plugs. The batteries are 12.6V each. The glow plugs are maybe 5 years old at most and the truck is only used occasionally, and normally starts without any issues. I think I remember that there is a relationship between the wait light and the glow plug solenoid. If the bulb fails does the solenoid not work? The solenoid is a few years old, and it's the second one I have put in so maybe not the best quality. I'm thinking I should just swap out the solenoid, but let me know if pulling the dash to check the bulb is a better first step. Thanks for the help this site is a blessing for guys like me . It's getting dark so I'm done for today, but I'll try it again tomorrow morning when its cold and report back.

Thanks,

Nate

 

[WWRD99]

Had you driven the truck previously that day that it was warmed up?

Sent from my SM-S906U using Tapatalk

 

[n8roro]

A few hours before so it could have been warm enough for no wait light. Tomorrow morning will be a better test.

 

[WWRD99]

A few hours before so it could have been warm enough for no wait light. Tomorrow morning will be a better test.

My truck does that. I can drive it for an hour then if it sits for about 45 minutes no glows. I put a push button in it just for that situation.

Sent from my SM-S906U using Tapatalk

 

[Guyfang]

You already have a thread on this problem. Is there some need for 2 threads?

 

[n8roro]

Good to know WWRD99! How did you wire that? Turns out your diagnosis was correct. The wait light came on this morning and all seems good.

Hi Guyfang. No need for 2 threads. I started this one and then remembered the other one from 2019 afterwards and thought I would update it.

 

[Guyfang]

So what thread should I nuke?

 

[WWRD99]

Good to know WWRD99! How did you wire that? Turns out your diagnosis was correct. The wait light came on this morning and all seems good.

Hi Guyfang. No need for 2 threads. I started this one and then remembered the other one from 2019 afterwards and thought I would update it.

Just saw this. I did a momentary push switch in the cig lighter. Hook to the second wire to get glows. The third does the wait light. I took this out of a 1008 cab I have, and it was wired to the third wire...I did the same, but it did not turn on the relay but it did turn on the wait light..so it never worked for them. I looked up the wire diagram and found the relay ground is the second. The switch is grounded to one of the bolts holding in the cig box. I'm not a fan of scotch locks but it's only a ground for the switch...can do it however you want. I'm not sure what would happen if you hooked it up to both the second and third wire to ground at the same time, if the card would smoke. If it wouldn't smoke it, I'd do both just for the wait light to come on, too. I don't want to try it, though, since my card works great otherwise!! I only do like a 8 second hold then it starts every time. I have new glow plugs so it starts good. I'm not sure why it doesn't start when it's warmed up and sits for an hour since I did the updated temp sensor in the drivers rear head. Had a few surplus ones.

Sent from my SM-S906U using Tapatalk

 

[Guyfang]

So what thread should I nuke?