Important ground connections to clean under hood? 2001

[Devil Black Diesel]

I have a 2001 auto that needs some TLC under the hood. I need to get in there and clean all the ground connections that would affect the APPS/TPPS and prevent excessive alternator voltage spikes. I have the famous erratic rpm syndrome that I believe is caused by excessive voltage from the alternator? Where are the important ground connections that I need to get cleaned up? Isn't there an important ground connections under the air intake? I have an AFE stage 2 intake and I see a wire going under it so i need to remove it and take a look.

Let me know where to look so I can get them all cleaned up. I live by the beach so there is some corrosion under there and I believe that's my problem. I have been driving the '16 but it's not as fun to drive so I need to get the old 2001 dialed in. Thanks for your help.

 

[DonFitzwater]

Take a read. I fought this truck for a while before finding the real root cause. Has been great ever since. https://www.turbodieselregister.com...-TC-lock-unlock-problem?p=2444761#post2444761

 

[Devil Black Diesel]

Take a read. I fought this truck for a while before finding the real root cause. Has been great ever since. https://www.turbodieselregister.com...-TC-lock-unlock-problem?p=2444761#post2444761

Wow, of all the suggested fixes out there I've never seen this one. Before it do it to my truck, I want to confirm what I'll be looking for. I drew up a quick "before/after" diagram to ensure I'm following your post correctly.

1. The top of the drawing shows the wiring in the stock configuration with the ground wire (orange stripe) ending near the driver's side front corner of the block and it's "twisted" together with (4) other small ground wires from the wire loom, with only heat shrink holding them together.

2. The bottom of the drawing shows it after the "fix". You ran the stock ground wire (orange stripe) along the radiator, extended it by butt splicing a piece of marine cable in there, and then butt spliced that to all (4) small ground wires, and then heat shrinked the (4) ground wires back to the loom.

Is this correct? Did you simply twist all (4) small ground wires together and then use one butt splice to connect it to the marine battery cable?

I really appreciate the feedback.

 

[DonFitzwater]

"Is this correct? Did you simply twist all (4) small ground wires together and then use one butt splice to connect it to the marine battery cable?"

Yep, we used butt connectors and heat shrink. I probably should have done a solder joint but that's all we had at the time and it's been working great ever since. In all fairness, we did use a marine grade, high quality connector and heavy duty heat shrink so it's not exactly a cheapo fix. I'm sure you could do the same and have success if that's your problem. I was able to verify the repair by watching all the signals before and after the repair on a Snap-On Solus scanner. They were very dirty and voltage bounced all of the place any time something turned off or on. After the repair, the voltages were all very linear and spikes/drops nearly stopped.

 

[Devil Black Diesel]

"Is this correct? Did you simply twist all (4) small ground wires together and then use one butt splice to connect it to the marine battery cable?"

Yep, we used butt connectors and heat shrink. I probably should have done a solder joint but that's all we had at the time and it's been working great ever since. In all fairness, we did use a marine grade, high quality connector and heavy duty heat shrink so it's not exactly a cheapo fix. I'm sure you could do the same and have success if that's your problem. I was able to verify the repair by watching all the signals before and after the repair on a Snap-On Solus scanner. They were very dirty and voltage bounced all of the place any time something turned off or on. After the repair, the voltages were all very linear and spikes/drops nearly stopped.

Okay great, now I have a "fix" to look forward to. I can't believe I haven't seen this anywhere else, but then again it looks like you found the issue in 2016. Not sure how soon I'll be able to get mine done but I'll follow up when I do. Has anyone else here tried this exact fix listed in Don's link?

 

[Devil Black Diesel]

To follow up on this, I haven't had time to perform the "fix" illustrated above yet, but I decided to spray WD40 on all my ground connections under the hood (they all have corrosion) to see if it would help at all. To my surprise, the truck has been driving perfectly after I sprayed the WD40 on the ground connections. If you are having the OD hunting and erratic shifting problems you might want to give this a try to see if it fixes your problem. Although it's a temp solution, it might tell you if it's your ground connections causing the problem or something else. Pretty sad these trucks are so sensitive that a little WD40 fixed it right up.