97 Hoe 4x4 350 LT Ignition Switch Ghosts

[JamesSloth]

Hoping to get some help ghost busting as I'm currently stumped.

My 97 Tahoe with 200k miles will lose tach, speedo, and shift indicator intermittently while under load or idle. I've read this is commonly due to a bad ignition switch so I went ahead and replaced it, but the problem seems to have gotten worse.
After replacing it idling in the garage the shift indicator would blink as if it was going out, and applying a light load would cause it to cut without killing tach, once it reached around 2.5k rpm it would kill both tach, shift indicator, and I assume speedo but that's an educated guess as it was a load in park not actually driving.
Jiggling the harness around doesn't seem to do much to re-engage or disengage so I know it's not at the connectors in the steering column, but I'm wondering what it could be now. When this happens I don't get any codes thrown, and currently only have 1 02 sensor code.
I'm getting a rebuild done soon and I want to make sure I get this seemingly electrical ghost taken care of before then so I don't shred a fresh rebuild.

A common theme I've seen with others having this problem is hard shifting or starting out in second gear but as far as I can feel it's shifting fine. (Maybe its just my old cluster isn't getting a good seat?)

 

[Donal]

Sounds like a ground is intermitted. I would be checking all connections for coroosion and damage. Connections at the switch, all control modules, pcm and transmission and places where the wiring harness is rubbing against something. Damage cause by rodents chewing is common. A bare section of a ground and a bare section of power maybe intermitten as well. IF all fuses show voltage on both sides of the fuse, check voltage with meter. Voltage should be same on both sides. Rodents are partical to the harness beneath the fuses and just below the master cylinder bracket and the harness going to the rear lights and transmission.

 

[Eman85]

As Donal mentioned check the grounds. Everyone forgets about electricity making the round trip and only focuses on the power in.

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

You are already receiving sage advice from the knowledgeable folks on this Forum.

 

[Hoesgottaeat2]

Welcome from NY.

 

[JamesSloth]

Look for bad grounds, look for chewed wires, and of course share photos.
While looking for grounds I guess I knocked my neutral safety connector and only had shift indicator in neutral, 3rd, and 2nd is this typical of a bad safety? Reinserting the plug fully seems to have fixed the issue, but while the trans is down I'm thinking I'll replace it if the guys rebuilding it don't
I also found my shift interlock bushing is out and isn't even connected! Hoping that's not as difficult to replace as it looks.


1997 Tahoe LT 2 Door
Lovingly named "Bad News"
She's a huge pain in the wallet and a work in progress but I'm hoping I can get her running for another 200k miles

 

[Miami-Dade]

Welcome from Miami&Queens NY!