91 Diesel Gauge Cluster swap into 89 Diesel Silverado

[theblurrrr]

Looking to swap a 91 Diesel Cluster into my 89 Silverado Diesel--I realize I may have to move a couple wires in the connector--anything special to get the Tach to work? Any advice?

Thanks in advance!

 

[someotherguy]

Look at 1991 diesel wiring diagrams for the tach wire and you'll probably find you need to add it to the 1989 harness since no 1989 GMT400 came with a tach...and only some 1991's did. Man you scored a rare cluster. Needle 1991 cluster uncommon as it is, many got the same moonie style gauges that 1988-1990 did...but to find a diesel 1991 needle cluster, that's like unicorn farts.

Richard

 

[theblurrrr]

This cluster is interesting in that it doesn't say "Diesel Fuel Only" next to the fuel gauge, only the word "Diesel"; and most of the part number label is worn off but starts with "15.."(almost all '92 cluster parts start with "16.."). The 3 letter code is partially gone, but starts with "Q" and ends with "X".
I've been trying to validate it since I bought it on eBay in 2013; the seller said it came off a 91 Diesel with a manual transmission. I've been trying to find more parts information, any ideas??

 

[someotherguy]

Put it to you this way: if it has needle gauges, but a metal back plate with the pin style socket, it is without question a 1991 cluster. 1988-1991 are all metal-backed with the pin socket, and only some 1991 came with needle gauges as all the rest are "moonie" style. Then when the full change to needle gauges occurred in 1992, the entire design changed and has a flexi-circuit backing with a "finger contact" style socket.

Richard

 

[theblurrrr]

That's what I have-with the metal back and pin socket. Thanks for the info!