Can you buy a complete engine wiring harness?

cbuttre835 · Jan 25, 2013

Well one truck is down (just won't start right); and the other truck has I guess what is an electrical gremlin.

I attributed it to a faulty CPS, then bad fuel... replaced CPS, replaced fuel tank (33 gallon Bronco upgrade) AND fuel bowl and all valley lines... truck has perfect fuel pressure while running (mounted a gauge on the hood from the Schrader valve port)...

So I start scanning it and find the IPR Duty cycle is between 15-30% at idle. I always thought 9-12% was normal.

I get under the hood to replace the IPR and find two wires going to the IPR have been hot enough in a couple spots to melt the insulation off. Plus that black loom is stiff and cracked and the red tape to the inj harnesses is flaking off.

I've fought off-and-on with this truck since September. I've had it.

I can't find a complete, new, engine wiring harness anywhere. Don't want anybody's used eBay woes. Do they exist or do I start unwrapping and tracing and repairing?

ghohouston · Jan 25, 2013

Have you called ford, or are you trying not to buy from them?

Bugman · Jan 25, 2013

I would be willing to bet that your only source is going to be Ebay, junkyard, or someone that is doing a part out. Ford is only required to keep parts on hand for a model year truck for only so long and then they discontinue them, so if you do find one it is going to be one that they just happen to have and wiring harness are usually one of the first things that go out of stock.

cbuttre835 · Jan 25, 2013

I went to fastpartsnetwork dot com is all. Haven't tried the dealer... might as well do that.

Patrick Feeley · Jan 26, 2013

Is the IPR wiring issue on the Fuel Bowl Wiring harness side? If it is, you can replace just that harness for about $50. Cheers!

cbuttre835 · Jan 26, 2013

Yea Patrick it is; it's been replaced once already with a used one though. Rockauto dot com has lots of Dorman connectors for various sections of the harness for cheap, but not any complete harnesses.

I taped up the melted insulation, and swapped in a different IPR today -- did not fix the problem.

Back to square one...

old man dave · Jan 27, 2013

Diesel seems to rot the wiring insulation to the IPR. You can use an old injector uvch plug to plug into the IPR.

Buying a complete underhood/engine harness from the dealer is out of the question. Each half is about $400 each and is probably no longer available, the California ones are obsolete for sure. Rebuilding the old harness is the only practical solution. The red tape is primarily a visual warning that it is high voltage wiring for the injectors and not 12 volt wiring.