Hey people, I'm new at this, sorry. My truck is a 1997 F250 7.3 diesel with 188,000 mi on it is fully stock, I'm the second owner, I have replaced the glow plugs, valve cover,and the under harness on the driver side all most a year ago. Last week after work I had the key on checking the turn signal flasher, I smelled hot wires a puff of black smoke. I turn off the key, open the hood, and its on fire, I put water on it, and fire is out. The fire was next to the glow plug relay fuel bowl behind the alternator. The small wires that turn on the relay are pretty burned up, all of the rest of the larger look ok just little heated. If I jump the relay it does work, doesn't make more smoke. I cut back the harness, and taped up any bare wires. The truck will not start, I'm just trying to get it home. Looks like I will be replacing the main harness, any thoughts out there? best place to get the right harness, and could this have harmed the PCM/injector module? I still have not figured out what wire caused the fire. This is my first diesel truck.
Thanks for your help.

 

Did you find out what actually caused the fire yet? I might worry about installing a new harness only to have it catch fire, too. RiffRaff sells harnesses, and they're good to deal with.

For your no start condition, does the engine crank when you try to start it? Are there any fuses that are blown? Can you tell if any wires are severed or damaged, especially in the area of the fire?

 

I was able to do checking at lunch, I cut back the harness more, and found no more burnt wires. The truck cranks, with no smoke. I checked all fuses under the hood all are good 12.9 volts on both sides key on. At the fuel bowl connector I have two wires with power on them with key on. I think the tach moves a bit when cranking. Also I pulled the two relays IDM/PCM they have .1 ohm across when closed, and they click when the key is on. So far the only wires that are really burned are the two that control the glow plug relay. The truck is Cali I'm having i hard finding the correct wiring diagram for it. New info the injectors passed the tickle test.My mechanic buddy thinks the IPR has shorted out and may have helped to cause the fire. the engine is not building high oil pressure. Now I'm looking for a pinout of the fuel bowl harness where it meets the main harness, so I try to test the coil of the IPR

 

.I dup. the reply

 

I took a pic

 

I wouldn't even try cranking until that is cleaned up. Wire, solder, high quality butt connections. Looks to me there has been some work done there prior. I have said it a hundred times on this forum. These trucks are old. Depending on the previous owners maintenance nearly every single part on the truck could need to be replaced but should at least be looked at. My harness was roached. Every single connector was broke in one way or anther, I decided hacking a 30 year old oil soaked harness was not worth it. so I ordered a new one. IMO these truck are now to the age that buying as a dependable daily driver is not a great idea UNLESS the truck has had good maintenance OR you are willing to sink the money, time and labor into making it dependable. Some people with money can take the fix it all at once approach, some people take the fit it after you are stranded approach. My approach is fix everything I can with the money I have. My two cents. Which in 2024 it totally worthless.

 

remove fuel bowl heater connector and see if fuse is right size so it wont happen again

New harness might be easier than fixing that up

 

New harness might be easier than fixing that up[/QUOTE]
In the pic I cut back the harness checking for brunt wires. RiffRaft sent me a email saying the main harness is no longer available, so any other good places to try?
Today I big puddle on oil under the truck I think the IPR is leaking. I plan to replace the IPR, and it's pigtail, rewire to main hardness as the fuel bowl connector a bit melted.

 

I have big puddle on oil under the truck form cranking it, ordered new IPR/pigtail, I think I going to splice the harness to get the truck home. If I could get all of the connectors and pins that fits the truck I would make one up using aircraft Teflon coated wire.

 

amazon has harnesses for sale for about 300 and make sure you get the Cali version, i see a shunt on GP

 

Ebay has brand new ones for $200

I bought a new harness for my 00 quality is ok, the only thing is the tabs on the connectors are kinda weak if your not careful with them if you ever remove them.

 

I just got back yesterday from a trip, I got the new IPR and pigtail from RiffRaff. Now I looking a tool to change it my socket is not deep enough. Does anybody out there know if a Crows foot will work? Thanks for the Amazon Ebay ideas. If anybody cares I measured the new IPR 12.15 ohms and 1.10 amps @ 13 volts

 

I use a axle socket. Cant quite fit the entire 3/8 drive into the socket becaue of the shaft on the IPR, but it works fine. I have used that to take my IPR out about 100 times.

 

Not sure if you got it figured out yet but I’d recommend pulling the valve covers and checking the gaskets and internal harnesses. Even with one side being new you never know but even more check the side that wasn’t replaced. Right before winter my truck just sputtered out on me driving to lunch and wouldn’t start back up. First thing I noticed when diagnosing it was my glow plug relay getting super hot to the point it was melting the wires and turning the copper around the posts white. Turns out both sides of the valve cover gaskets and internal harnesses were all cooked. Plugs were melted together so bad I had to chisel them apart and it was shorting out my glow plug relay. New valve cover gaskets, harnesses, and wired on all 4 new pigtails and it’s been great ever since. I’d go ahead and replace the relay when you fix the problem too

 

I will be checking that thanks, I ordered IPR tool, and a ratchet that has a twist handle to see if helps get at the IPR. Today after spraying solvent around the area to cleanup the mess, so can patch the harness I pulled on few things, I found burn thru high pressure oil line, there is my oil leak. I ordered new oil lines, and fuel lines.