Constant Cycling While Running

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Mar 27, 2015 | 02:11 PM

jafledd

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Constant Cycling While Running

I have a 91 F250 with the 7.3 IDI, I just replaced the glow plug controller and glow plugs. The issue I am having with it is that after properly installing the new controller and the glow plugs it cycles even when the the truck is running I can see it on the battery meter and hear it cycling. I am confused as to what it might be and tried skimming the 1000's of threads and post but cant find the same issue I am having. Any wisdom from the masses would be great. Note the controller cycles for 5-10 seconds as it should followed by the on off if you wait to long so it seems to be operating just fine in that aspect. Thanks for your time.

Mar 27, 2015 | 02:23 PM

bashby

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From: Charles Town, W bygod Va

It is normal to cycle for a few seconds after it starts. Is that what it's doing or is it all the time?

Mar 27, 2015 | 02:34 PM

jafledd

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long enough to smell burning wires. That is when I deiced to shut it off. At that point I ensured that the ground was good and tried it again with no change. Any ideas ?

Mar 27, 2015 | 03:22 PM

bashby

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From: Charles Town, W bygod Va

I think the only thing it could be is a defective controller. Did it do the same thing with the old one?

Mar 27, 2015 | 04:35 PM

jafledd

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The old one did nothing at all, think this problem might have been the reason it died so when it stops raining I will get back out there and pull it and see if there is anything out of sorts and more than likely send it back to the mfg.

Mar 28, 2015 | 06:04 AM

tjc transport

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From: Marlboro Mental Hospital.

if the coolant temp sensor is bad, it will not tell the controller the engine is warmed up and supply it constant power.
once engine temps hit 110 degrees, the coolant temp sensor tells the controller to turn the glow plugs off.