i've got a 94 f-350 with the 7.3 IDI, non turbo. when i turn the ignition on, the wait to start light comes on, but i dont get the "clicking" and the amp gauge bouncing like i've seen most fords do. however, the truck usually starts fairly quickly, there have been a few times when it will crank for 30 seconds or so and still not start, usually if i try it again in a minute it will fire. i went out the other day, and it did click, so i think it may be an intermittent problem. what part of the glow plug system could be at fault? i'd like to get it fixed before the cold weather sets in.
dont think my glow plugs are working
- Thread starter p575
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Compu Doc
Full Access Member
My glow plug controller used to click. Now that I replaced all my glow plugs and found 3 bad ones it doesnt click at all. The wait to start light stays on longer than it used to also now that there all working.
I would check the glow plugs first you might have a single bad one. If you find there all working then replace the controller. If you find a bad glow plug then replace it first to see if its better. Remember to only use Motorcraft and not autolites.
I would check the glow plugs first you might have a single bad one. If you find there all working then replace the controller. If you find a bad glow plug then replace it first to see if its better. Remember to only use Motorcraft and not autolites.
I've found a fairly quick way to diagnose bad glow plugs is this... rig up a way to measure the voltage at the #2 cylinder glow plug without disconnecting anything. When you hit the key, the 12 volt battery voltage should fall to 6 or 7 volts at the test point, and climb slowly up to 11 volts or so within the normal "wait to start" time frame. If your voltage is higher when you first hit the key, then you have glow plugs which are "open", and you can then test them individually with a test light. Welcome to the site! Be sure to read all the FAQ's at the top of this forum. 
Rob94F250
Registered User
I agree with Compu Doc. Now that I have 8 new ones installed, there is no clicking (which it used to do, at least 2/8 bad plugs), the light stays on longer, but I think you should still see the volt gauge drop down with the glow plugs on.
I didn't test mine before hand using Agnem's test method, but he has some good advise in his post.
Rob.
I didn't test mine before hand using Agnem's test method, but he has some good advise in his post.
Rob.
