Ground Wiring Question

[Ball4226]

I found some interesting ground wiring going on the other day when I was cleaning up a few things under the hood. The pictures are attached below, I understand the ground wire that is not connected is the PCM grounding strap but for some reason its been disconnected and another ground has been added. The new ground goes from the computer all the way over to one of the bolts on the intake horn.

Is there some grounding mod that Im not understanding here? I cant imagine any reason why someone would add a longer grounding wire...

As always, thank yall for the help!

 

[WalterJ]

My guess: 1st owner had strange issues/codes, sought advice re: verify PCM or computer grounding, saw that a nearby clean bolt offered a better connection (his thought) than a fender or firewall sheetmetal.

That's 'his' story & I'm stickin' to it.

 

[Timd32]

All sorts of shady shortcuts were taken with the grounds by the factory, some were production errors (bad splice techniques), some were engineering errors (not choosing a clearer path and bundle errors: putting signal, supply, returns all in the same harness).

A few reasons for seeing that. There are more.

TC lock up issues
Alternator AC noise issue
High Output Alternator Upgrade

I would not revert back to stock as some model harnesses are junk and have all sorts of bad spices in the ground system and underrated wiring for certain mods. Edit: not saying the mods in your case were done correctly either, they could have left the wrong strap off that is needed.

You might have to do some digging and figure out the wiring and note it for future troubleshooting.

I have not heard of any distinct errors of the electrical schematics that you need to correct, except in the undersizing alternator wiring on some trucks with a lot of added accessories. That is not on directly the ground side.

 

[Ball4226]

Yeah this just seems excessive. I have replaced the alternator (routine maintenance), installed a BD noise isolator, and the TC locks up as it should. Most of the time anyways!

I’ve read all about MoparMan’s thread on rewiring the ground on the alternator. The TC issues I have on my truck I think are also more linked to the APPS and not AC noise. But I definitely need to look into it.

Any idea on a way to test which ground would be best for the computers? From what I was reading the grounding strap was just installed from the factory to eliminate as noise from the computers but wasn’t a ground to complete the circuit.

 

[Timd32]

The only thing I found was a TSB for the early trucks that did not have a decent ground strap from the cab to the frame, that should not be the issue on your truck.

One thing I think of is voltage drop when dealing with nasty connections. I found this fluke blog to have some useful stuff, and some odd stuff like the thermostat housing ground comment, no clue what year that is in referene too.... but overall offers a decent opinion on Voltage Drop and testing grounds.

https://www.fluke.com/en-us/learn/blog/automotive/electrical-automotive-troubleshooting

 

[Ball4226]

Sweet! Ill give that a look through!

 

[Ball4226]

Any chance someone has that ground strap on their truck connected to the computer? Or a stock wiring diagram for non EE people (i.e. for dummies)