Hi all,

Went to start my 1990 F250 7.3L diesel (with aftermarket ATS turbo), and it had a dead battery. I tried jumping, but she
wouldn't start.

While fiddling around, I noticed that one of the plugs in
the harness was melted. It is at the front right of the
engine bay (right as you are sitting in the drivers seat).
I pulled this apart, and doing some fiddling, I noticed that
when the glowplug circuit kicked in, one of the large
diameter wires would draw a lot of current and immediately
start to heat up.

I am about to start pulling the thing apart (going to be a pain,
'coz I think I will have to pull off the turbo!), but I was
trying to think of a cause of this failure. I tested the engine
block heater for the first time the other day (well, just
plugged it into a GFCI socket to make sure it wasn't going
to short out or anything). Could this possibly have any
relation with the glow-plug problem? I thought both systems
were sperate, but then you never know...

Any suggestions on what I should look for in the glow plug
system, aside from obvious shorts?

Thanks,
Chris.

 

Hi again,

So, I managed to pull the glow-plug relay out. Before just
replacing it, I was wondering how I could test it. I did some
checking of resistances - the glow plugs are all ~0 Ohms.
Also, the big twisty piece of metal on the side of the glow plug
relay measures 0 ohms. Does the relay do any current
limiting? seems to me that as soon as it switches on,
there is going to be an effective short on the supply
wires....

All help appreciated!

Thanks,
Chris.

 

When the ATS turbo system is installed on the 7.3 idi, it is necessary to loosen the power wire on the glow plug controller and turn it toward the driver side of the vehicle. this is done to move the wire away from the downpipe and avoid any shorting in that area. Look that area of the wire over to make sure it didnt get hot and melt the insulation off the wire.
Why the glow plugs melt down the way they do is not understood by me, but they do it.
I thought the controller either works or it doesnt. When it is working, you should hear clicking when the "wait to start" light is on. I have also found, that the hot wire on the controller may become corroded and needs to be cleaned in order for the system to work effeciently.
I have also found, that one glow plug malfunctioning will cause the engine to start hard in the winter months -- go figure. It must be a female thing.
Any way that is the way I have found my idi to work. My opinion and that is all. Best of luck.