95 7.3, stock truck other than the transmission which is Brian's Truck Shop unit. 260,000 miles. This truck is a crew cab with a flat bed, daily driver for my business and does all our hauling and trailer pulling. last week the supt. who drives it was leaving the shop when it drove about 30 yards then fell on it's face. Barely ran, wouldn't pull it's own weight. Investigation found bad vc wiring. Bought a complete kit from AccurateDiesel replaced gaskets, pigtails and glow plugs on both sides. Started the vehicle, no cylinders on the right bank firing. I can unhook both harness connectors and no difference in performance. AccurateDiesel sent me a pin out diagram for the harness and everything checked out fine from IDM plug to valve covers. All solenoids read the exact same resistance, 2.6 ohms, measured at the valve cover connector. I have replaced the IDM with a reman, no change. I have been an avid reader of this forum for years, fixed numerous problems with in my fleet of Ford trucks from the wealth of knowledge that is shared here. I have been thru probably 250 threads that I thought might shed some light on my challenge and did get some great things to pursue. Done everything I know, looking for a little help!

Thanks.

 

What BRAND of harnesses did you get?

Have you done a buzz test?

 

I bought the early meltdown kit from AccurateDiesel. I currently don't have the resources for a buzz test.

 

When you replaced the pigtails to the valve cover gaskets, did you solder them together, or use butt connectors?

 

They are all soldered and heat shrink. They were changed 1 wire at a time, cut, solder, cut solder to eliminate any chance of cross wiring. I did the pin out from the IDM plug after pigtails were installed. I checked the injector coil resistance thru the new vc gasket connections today, at the gasket connections.

 

It is a little interesting to me that the original failed valve cover harness was the left side, but after everything was repaired it is the right that is toast.

 

Just kind of because.

Why did you replace the pigtails on the main harness?

That's a last resort sorta thing. You might have derped yourself doing that when it was just bad UVCH and VC Gasket.

 

They were in need of replacing, the work is in getting to the wiring, the insulation was brittle and damaged on the glow plug connections, the harness connectors were in pretty sad shape.

 

I have the AE scan tool, but the I think the sofware for 7.3 is on a laptop that is on a job site that I can't get to until tomorrow. I have the standard software on another laptop but I could not get it to connect to the truck yesterday. I haven't had to use it in a long time, but I think I recall the 7.3 program was different than the standard. I bought the 7.3 and enhanced Ford software quite some time ago but have probably only used it twice.

 

Sounds like you know what your doing. But, just to be sure, you did used the middle pin on the valve cover gasket for ground lead when measuring injector coil resistances? That middle lead is common to the entire bank and supplies HV to the injectors. The other two pins next to center are pulsed to ground to actually fire the injectors by the IDM.

 

Yes, the middle pin and the pins on either side for the coils the outer 2 pins for the glow plugs. Thanks for checking!

 

Just to dump more fuel on the fire here.

Shoulda done the SD harness upgrade if you were doing that much. Worth every penny.

 

Your pretty helpful.

 

Yeah, I did this myself here recently. I didn't have to but it was worth it. The more skookem pins of the SD harness is worth it in the long run.

Those top clips have to be damn near destroyed though before I'll ever solder new ones on the harness again.

I doubt you got them messed up soldering them in. More than likely the connectors are not tight someplace. I don't recall seeing you saying that you took the VC back off and checked the internal connections.

There is always a possibility you have the same issue as I do with your harness. I have a short or a weird spot in my harness that if i move it a certain way it will shut the whole bank off. To scared to look into it as it works.

 

We did pull the valve cover and check all the connections, even pinned them out with a meter back to the harness plug. I am wondering now whether there is something going on in the harness between the IDM and vc harness. I have read about a common problem being where the harness crosses the left valve cover creating some chaffing. If what ever causes the idm to shut down 1 bank still sees a problem, it must be somewhere other than the right bank new wiring.