So I've been chasing an eletrical problem(when I had free time) for the past few days. Finally narrowed it down to the grounding strap that runs from the battery down to the chasis and then to the starter. The section that groudns to the chasis will not ground dispite having a clean mounting area and bolt being fastened snug. If I run my voltage meter from the posutive post to that ground strap I get between .2-.4V but if I take my voltagemeter and press the negative directly to the frame I get the same reading as running direct from positive to negative post.

Now my question is I looked up the replacement harness and its anywhere from $380 to over $450 depending on retailer. Should I try to locate one at a junkyard? Or can another can another harness be made? Outside of the fusable linls running bteween the positive and negative posts the ground end looking like it grounds up to the firewall with a roughly 14g, to the frame with a 0g and 12g and I'm assuming either one or both of them runs back to the starter.

 

I'd look at a junkyard.

For what it's worth, I've got a place that sells batteries and other hardware for repairing high load apparatus like 10 minutes from me. They can rebuild harnesses and they have a hydraulic crimper with all kinds of ends and ferrules. Not sure if that would be cheaper than a junkyard, but it's worth a shot to ask a place like that in your area, if you can find one in your area. I know they can also look at it, and determine what the problem is, far cheaper than a dealer or even an auto shop. At least in my experience dealing with this particular venue.

 

Alright thanks. I'll pull the harness tomorrow and just give it a visual inspection out of the truck and take it from there. The whole thing happened directly after swapping in a new motor so I'm guessing in the process of maneuvering the old one out and new one in it got pinched or otherwise damaged.

 

Yes, that could happen if not careful.

Also, one thing to note when testing, continuity tests are helpful to determine if you have any connection, but load tests can show the performance of wiring. Like for example, a continuity test will show that you have at least 1 strand of wire in path. However, 1 strand out of say 0 gauge stranded wire will not hold up to any current and will fail a current draw test.

 

did both continuity as well as a dc voltage test. Continuity was all over the place and voltage read between .2-4v fluctuating. Which is the same voltage the coils pack connectors were reading. I rand a 4awg wire from neg terminal to frame and another mounted at same point from frame to starter ground. Reran tests between .000-.002 on continuity and voltsge reads same as battery from the mount point. Coil packs now also read same voltsge as battery when key is on.

 

So a little update. Grounding seems to be all sorted out. But the truck is still having mostly the same issue. But did some more diagnostics and found the crank sensor signal isn't being picked up by computer, the injectors get stuck open abd are dumping fuel causing the fuel rail to not hold pressure. The coolant temp sensor is pegged at 315° despite not once firing and air temp sensor is reading -40°. Coils still aren't firing as well.

at this point I suspected harness damage or similar eiring issues. So I pulled the intake, disconnected the harness bracket and pulled the harness out and tested each pinout to its respective sesnor pin for continuity(had no accurste disgram so had to mostly just blindly test til I found a good connection) I found every wire to be good. With the execption of one loose ground pin that got fluctuating reading(which was fixed and now reads good). Now basicallyI just want to be sure that ground was related to the aformentioned sensors to ensure that was the entirety of the issue before I start throwing this all back together again only to find it potentially still giving me issues.

 

i am pretty sure the wiring diagram is posted HERE somewhere.....it is a pdf download....IIRC