Help installing 90 Burb Cluster in 79 C10

[Mickeymotormount]

Your wiring may be similar to what I have with my '93 truck. I wired the speedo directly to the PCM red connector pin 50. I have a '99 harness so you probably want to double check to see if it is the same on your harness. According to LT1swap.com., your pcm pinouts should be similar. You should have a dark green/white wire at pin 50 on the green pcm connector. That wire is the 4K output wire. That controls the speedo.
According to my '93 wiring diagram, the instrument cluster plug has a light blue/black wire in the S position of the plug. That is the speedo wire. Just cut the wire and solder the wire from your new pcm to the end of the wire so as to reuse the little connector in the plug. Your speed should now work.

Good luck.

[dayman]

Really appreciate the information. I will look at the harness and PCM tonight. Harness is a Painless harness drive-by-wire and the dash cluster is out of a 1990 Suburban.

[dayman]

I completed the install of the 1990 Burb cluster in my 1979 Chevy Silverado. I traced the harness on back of each cluster and re-pinned the connector to match the 90 cluster. It took a couple hours to get everything in the right place, but now all the gauges and the speedometer work.

I took pics of everything before I made any changes so I could reverse the process if I could not get things to work.

Thanks for all the feedback for help.

[Mickeymotormount]

Glad to see everything worked out. Let us know how you are enjoying your swap.

[swiss]

I completed the install of the 1990 Burb cluster in my 1979 Chevy Silverado. I traced the harness on back of each cluster and re-pinned the connector to match the 90 cluster. It took a couple hours to get everything in the right place, but now all the gauges and the speedometer work.

I took pics of everything before I made any changes so I could reverse the process if I could not get things to work.

Thanks for all the feedback for help.

Dayman,
I need help can you send me picture and also tell me which color wire you used from the 1990 Cluster to connect to the LS swap VSS. I have 1984 c10 and I'm doing the 5.3 LS swap with 4L60E tranny. This is the last thing i need to complete the project.
if you would like to email me with pic
velken2010@yahoo.com