help

[jerrylee]

99 250 psd 4x4 blowing main pcm fuse (30 amp) #30 in dash fuse pannel. Replace fuse truck ran good till it sat overnight, turned key on wait to start came on i heard a pop at about 3 seconds and light went out. turned key off replaced blown fuse, turned key on and the fuse blew instantly. i waited an hour and then replaced fuse turned on key that time wait to start light came on and stayed lit, after about 15 seconds the light went out so i engaged the starter and as i did i heard the fuse pop again? any ideas?

[ABOBB]

Welcome to Powerstroke.org

I'm sorry to say I can't help you with your problem, but would like to welcome you to this forum. There are lots of great folks here, and with this "bump" back to the top, I'm sure you'll get some answers soon.

[SMKSTAX]

Here's a bump for ya!!

[dieseldan2005]

not sure, but maybe the glow plug relay is going out, causing it to short. Maybe? I know that they are prone to going out causing hard starting issues, but never heard of one blowing fuses.

[fordmt]

If I remember correctly (no access to wiring diagram right now), I think the fuel heater is on that circuit. This is a known issue. Replacing the fuel heater should solve your problem.

Mike Cleary
Ford Certified Senior Master Technician and Powerstroke Engine Specialist
Automotive Technical Support Services
Specializing in Ford Vehicle Systems Training
P.O. Box 27522
Fresno, CA 93729
mcleary@atsstraining.com

[Strõkër~X]

can you try a bigger fuse?

[fordmt]

Absolutely not!

[-larry]

Hi! I had a fairly similar experience with the sudden onset of fuzes blowing in my '99 7.3L Powerstroke Diesel. Not too long prior to the fuse issue, I had been mucking around under the dash and I had inadvertently moved a hot wire to where it could ground out. It was intermittent at first and then went from merely being a nuisance to constant short! It was such a difficult find that I shorted the fuse block for a few seconds and then looked for the hot (thermally) wire, in order to trace it to the grounding point. There IS risk involved in this approach--ultimately it could melt a wiring harness (messy and expensive) or cause a fire (full loss of vehicle, here)--so I advise extreme caution, if you try it. Good Luck! :-)
-larry

[fordtech2004]

im pretty sure "fordmt" is correct about the fuel heater, but i forget what fuse normally blows when that shorts out...i could check the diagrams if your still having problems