Bloock Heater Issue

jimpaget · Jan 2, 2016

It appears that I have a dead short somewhere in the block heater circuit on my '97 Powerstroke. Each time I plug it into a circuit it immediately pops the GFCI. I have tried 3 separate circuits with the same result.

The good news is the really cold weather is coming to an end for a while, anyway.

Where should I start looking for the problem?

crash2 · Jan 2, 2016

unplug it at the block and check for a short to ground and in between the plug (cable shorted together). If that checks then its the block heater.

t1h5ta3 · Jan 2, 2016

unplug it from the element, replace the cord. 10 second search and amazon has'm for $20 a few mor secons searching and can prob find cheeper...

!ton327 · Jan 2, 2016

Is it only on a gfci circut?

zukkev · Jan 3, 2016

CRAP Jim, I am sorry, I didn't call you back yesterday! Lol

The block heater is mounted on the oil cooler, driver's side of engine, above the oil filter. Probably not somewhere you are getting to easily at the moment. Do you have any time to run up? I can check it out for ya...

zukkev · Jan 3, 2016

t1h5ta3 said:
unplug it from the element, replace the cord. 10 second search and amazon has'm for $20 a few mor secons searching and can prob find cheeper...

You can also run down to your local ford dealer...The guys in the shops usually have about a dozen cords layin' around... :redneck:

crash2 · Jan 3, 2016

I prefer to diagnose it than throw parts at it--thats just me :awesomework:

jimpaget · Jan 3, 2016

crash said:
I prefer to diagnose it than throw parts at it--thats just me :awesomework:

Since I am recovering from a shoulder replacement and a couple of lame wrists, I took the rig to Kevin's place. Turns out it was the block heater itself rather than the wiring. Off to see a friend at the Blue Oval Store in the morning.

crash2 · Jan 3, 2016

jimpaget said:
Since I am recovering from a shoulder replacement and a couple of lame wrists, I took the rig to Kevin's place. Turns out it was the block heater itself rather than the wiring. Off to see a friend at the Blue Oval Store in the morning.

Myself I would be shocked if the harness was shorted but assumption gets you burned easily in the automotive field.

DHR Darren · Jan 3, 2016

How did you determine it was the heater itself?

WA-Wheeler · Jan 3, 2016

DHR Darren said:
How did you determine it was the heater itself?

Ohm it?

jimpaget · Jan 4, 2016

WA-Wheeler said:
Ohm it?

yep, you got it

ain'tstuckjustresting · Jan 4, 2016

Weird, of all the 7.3's we have at work I have never had a block heater fail. The cords fail pretty regular though.

DHR Darren · Jan 4, 2016

ain'tstuckjustresting said:
Weird, of all the 7.3's we have at work I have never had a block heater fail. The cords fail pretty regular though.

Same here. That is why I asked about the heater failure.

zukkev · Jan 5, 2016

Shorted fellas...I didn't fall off the turnip truck yesterday :kiss:...
I also checked for continuity through the individual circuits on the cord...the cord tested ok, the heater not so much...We are gonna replace both, as the cord is also the OE unit...And I have seen a few 7.3L heaters fail, but they usually failed open, not shorted...

t1h5ta3 · Jan 6, 2016

ain'tstuckjustresting said:
Weird, of all the 7.3's we have at work I have never had a block heater fail. The cords fail pretty regular though.

zukkev said:
Shorted fellas...I didn't fall off the turnip truck yesterday :kiss:...
I also checked for continuity through the individual circuits on the cord...the cord tested ok, the heater not so much...We are gonna replace both, as the cord is also the OE unit...And I have seen a few 7.3L heaters fail, but they usually failed open, not shorted...

exactly. we replace atleast a dozen cords a year on fords, almost all of them rubbed thru from drivers yanking on them etc. i think ive seen 1 heater its self fail open, never had one fail shorted.

but yes mike, i still do due dillagance and test things before replacing.