new to this forum, I tried the search but no luck so maybe you guys can help me out. I have a 85 f350 4x4 crew cab. About a month ago i notice that I couldn't start the truck anymore. I found a burnt wire the red one from the fuel shutoff to the fuseable link was burnt and exposed. I changed the damaged section of wire and all was good in the world. then 2 days ago I noticed smoke coming from behind the dash When I removed the dash I found the same red wire burnt the whole way. I replaced the wire again with the same gauge and gave it another go. This time the wire started to get hot again so I shut it down the wire that felt the warmest was the red wire that goes to the temp switch for the cold timing advance and high idle. So I removed the switch, it looks to be in pretty bad shape, all cracked and corroded. Could this switch have caused the wire to get hot? I grounded out the yellow and red wires that go to this switch and turned the key over just to see if I could hear the fuel shutoff click. and it did and the wire didn't get hot. Is there a way to check the fuel shutoff to see if that is the problem? If it is, can it be replaced or is that more of a pump rebuild?

 

definitely sounds like a switch problem, if they dont get hot when you hear it click while grounded then it may be resistance building at the switch and causing problems. Should be able to get it replaced without a major overhaul. Not sure where to buy one though

 

Is the wire to the fuel heater, the fat part around the fuel line between the lift pump and filter housing shorted out?

If I remember right it comes off the wire to the temp switch right before the temp switch connector.

www.mwfi.com has the fuel shut off solenoid listed on the web page.

 

I had a similar problem last year around August. Wife was in the truck and I was feeding my goat. She starts yelling "the truck is smoking". I thought it was just diesel smoke, but when I got to the truck all sorts of smoke was coming out from under the dash, I think it was on the passenger side... smelled electrical. Anyway, never found out what it was...????? Did not even know I had a fuel heater, I will have to check into it.

 

well this is what I found out so far. with the temp switch unplugged the truck runs fine when I plug the yellow and red wires back into the switch and wires start to smoke immediately. I ordered a new switch online for $32 at the ford dealership it was $60.

 

I ordered 3 different switches from 3 different places and got the wrong one all three times (the new model with pins), even though they listed it properly. I finally got the right one from Ford.

PN: E8TZ 9E939-A

It is listed for $60.60, net for 38.20.

Total was $40.11 out the door!

-Enjoy
fh : )_~

 

sounds like you got it.
welcome to FTE.

 

rustbucket350,
I forgot to welcome you to FTE and the forum last night.....Welcome to FTE and the IDI diesel forum.

Check the harness between the switch and the IP.
Also unplug the fast idle solenoid and timing advance solenoid, then plug the wire in ands see if it still gets hot.

If it don't, plug in the timing advance, then the fast idle solenoid to see which one of them is shorted out.