Another Glow Plug Question????

travelinman31

Full Access Member
Joined
Nov 22, 2010
Posts
118
Reaction score
3
Location
n. texas
My wife was going to be nice one morning and decided she would crank my truck for me as she was leaving for work to let it warm up. I got to work and everything seemed fine, until she called and asked "how long is the glow plug light supposed to stay on?". I told her it normally stays on 10 seconds give or take on a cold morning which it was. She said it stayed on for nearly 2 minutes, I've taught everyone around here to wait on the glow plug light on the '85 or wait to start light on the later model truck we have. But I wold have never thought she would have waited 2 minutes.

Anyhow long story short, I'm sure it burnt out all of the glow plugs (they are probably originals). I haven't been driving the truck lately so it has just been sitting, I haven't plugged it in because I'm not sure of which block I have. I have cranked it a couple of times on warmer days and it is a struggle but I can get it cranked if the ambient temp is high enough.

My question, the glow plug light comes on and clicks off like it used to (about 10 seconds), but you can tell there is no glow plug assistance in cranking from the white smoke that rolls after it fires up. What device in the system likely stuck to leave them on for 2 minutes, and now not? Controller or relay problem? Or combination of both? I had an issue last year where the glow plug light didn't come on, I popped the hood and just touched the controller (behind the air intake) and light came on, not sure what I did probably a connection. Never another problem until the morning the wife was going to be a sweetheart.

Replacing the glow plugs is next step, but I'm wondering what else I should replace??
 

madpogue

Full Access Member
Joined
Mar 16, 2009
Posts
1,707
Reaction score
169
Location
Madison, WI USA
You'd have to wait 'til it happens again. Then check the voltage at the positive wire to the coil circuit (small terminals) of the relay. If there's voltage there, then the controller is supplying power and it's the thing that's stuck. If there isn't voltage there, but the GPs are still running, then it's the relay that's stuck.
 

franklin2

Full Access Member
Joined
Feb 24, 2009
Posts
5,194
Reaction score
1,440
Location
Va
If he has the old style controller that screws into the engine, I thought they had a known common problem of failing in the on position?
 

Forum statistics

Threads
91,310
Posts
1,130,149
Members
24,120
Latest member
SixFourShanks08

Members online

Top