88-91 to 92-94 cluster upgrade

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munrom77

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Hello all,

I am wanting to swap out my moonies the cluster itself is starting to fail, having over 500,000km on it I figure it’s time for replacement.

I have 2 gauges from the 92-94 sitting in my shop and have connectors, I still have the drac to remove but that is minor.

Right now I’m looking to see if anyone has access to the how to that used to be on full sized Chevy forum, I am unable to find any kind of working link.

Any help will be very much appreciated thank you all!


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DerekTheGreat

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You can go that route, but it's really labor intensive and yes, you'd need to wire up and mount the drac module from the 92-94 cluster somewhere in your vehicle. The easiest route is to just find and use the 1990.5 cluster which accepts your existing harness. There's a thread on here on how to install one of those. I've done it twice, the gist is you swap two(?) wires and run another for the tach signal. You might also have to recalibrate the speedometer if the cluster you have isn't set up right for your gears and tire size.
 

someotherguy

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Hello all,

I am wanting to swap out my moonies the cluster itself is starting to fail, having over 500,000km on it I figure it’s time for replacement.

I have 2 gauges from the 92-94 sitting in my shop and have connectors, I still have the drac to remove but that is minor.

Right now I’m looking to see if anyone has access to the how to that used to be on full sized Chevy forum, I am unable to find any kind of working link.

Any help will be very much appreciated thank you all!


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I've hosted the article and pics you're talking about: http://someotherplace.com/info/clusterswap/cluster.html

You can go that route, but it's really labor intensive and yes, you'd need to wire up and mount the drac module from the 92-94 cluster somewhere in your vehicle. The easiest route is to just find and use the 1990.5 cluster which accepts your existing harness. There's a thread on here on how to install one of those. I've done it twice, the gist is you swap two(?) wires and run another for the tach signal. You might also have to recalibrate the speedometer if the cluster you have isn't set up right for your gears and tire size.
The cluster you're talking about is 1991 and not in all of 'em.

Richard
 

DerekTheGreat

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Hmm. I was under the impression 1990.0-1990.5's all had the moonie stuff still while the 1990.5 to 1991's had the needles. I've found three clusters, took two. I can't recall what year the trucks were though but I do keep my eyes open any time I see a 1990 or a '91 in a t'weasure yard.
 

someotherguy

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Hmm. I was under the impression 1990.0-1990.5's all had the moonie stuff still while the 1990.5 to 1991's had the needles. I've found three clusters, took two. I can't recall what year the trucks were though but I do keep my eyes open any time I see a 1990 or a '91 in a t'weasure yard.
Guaranteed they were in 1991 trucks unless someone had gone to the (minor) trouble to swap. 1991's generally had moonies, too; there weren't a lot of them that got the needle cluster.

Richard
 

DerekTheGreat

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I can say that the vehicles I pulled my units from didn't have any modifications to the dash. I believe I followed your write up and I had to cut a considerable amount of plastic behind the cluster to be able to pull the harness up enough to modify it & move the wires around. The cluster that is now in my truck was probably a replacement unit for the truck I pulled it from, it had that ultra rare & now obsolete reprogram kit in it.

Random: What tool would you recommend to pull the needles off? My speedometer is consistently off by 3mph so I'm thinking the fix is to pull the needle off, get the cluster to read say 55mph and then stick the needle back on at that speed so it's right. I've checked mileage against mile markers on the highway and 1 mile is indeed 1 mile on the odometer.
 

someotherguy

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When I say they might have been swapped, if it was a 1991 needle cluster, the only change needed to put it into a 1988-1990 moonie gauge truck is moving a couple wires around in the connector. The connector on the 1991 needle cluster are nearly identical to the moonie gauges and the speed sensor buffer circuitry is integrated into the cluster, no DRAC. The entirely different connector and the DRAC are 1992-1995 (and 1995 of course is the whole different new design dash.)

For removing the needles I *carefully* use a fork. It's not really difficult to get them to pop loose, you just have to be careful to pull straight up as possible. The biggest challenge in pulling needles is to not mark up the gauge face; even wiping it with your fingers or a paper towel can leave a mark that can be hard to remove.

BTW as far as that rare 88-91 programming kit goes - if one really wanted to, they could make their own. It's just jumpers. The first step is supplying 12V to that little group of fuses inside the cluster that serve as the original jumper settings; once the fuses are all blown they are now open, and the clip plugged in replaces their function as jumpers. You would arrange them the same way you would set a DIP switch. They're just far less versatile than being able to change settings easily if your first calculations weren't as accurate as you liked.

Richard
 

kenh

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It would be some work but you could unsolder the resisters/fuzes or what ever they are, from your old cluster and resolder them into the new cluster.

Ken
 
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