Hi there
I have a 88 f250 with following problem: My truck started not to heat the glow plugs anymore; the light on the dashboard "Wait to start" would only light up for a blink of the eye instead of a few seconds. Though I still could hear the relay on the glow plug controller clicking. Also the former owner installed an button to activate the relay manually, to "glow some more" which also still activated the relay but didn't heat the plugs.
So a friend advised me to change the controller and all the plugs, which I did. Then it worked again but only for a day. Next day same problem, the light would stay on only very short. So i thought maybe the controller was bad and changed it for another new one. Put it in but didn't help at all.
The relay is till clicking but somehow the plugs do not glow. I also checked the batteries and the wiring and everything seems to be ok. I also checked all the new glow plugs again with an ohmmeter and they seem all to be ok. So my question is, what else could it be? What should I check next?

PS: for now I am starting the truck with the help of a little ether when the engine is cold. It works fine, but the valves might not like it too much???

 

welcome to FTE.
what type glow plugs did you put in? these engines only like motorcraft ZD-9 glow plugs.

i would suggest reading the glow plug thread on top of this page: https://www.ford-trucks.com/forums/9...le-system.html
this will help you get the glow plug system in proper working condition .
as for the switch to "help the plugs glow some more" the controller does that automatically for up to 2 minutes after the engine starts to help keep it running on startup.

 

Ok, so here's what happened: I checked all the plugs (Autolite) in the head and they had all around ) 0.5 Ohms. Then I checked my cables to the controller, which were ok. Voltage to controller was about 12.5 V When I turned the ign. key contact was closed and I could read voltage at the connectors to the glowplugs 12.5 V But the plugs would not heat. I also shortened the controller with a screwdriver with the same result; the plugs would not draw any current.
So I went to take one of the plugs out and hooked it up directly to an External battery and nothing happened, no heat. So i got the good plugs now, Motorcraft ZD-9 and everything works fine now. No need to glow "manually" anymore, the controller closes the contact long enough so to heat up the plugs where I can start it on it's own.
Lesson learned; some things it's just better to spend more to get the quality stuff.
Thanks
pj

 

It amazes me that Autolite manages to sell any glow plugs. They're crap no matter how you look at them.

Good to see you found out the problem. And we can all add this to the "Autolites are capable of only lasting as little as one single use before burning out" list.