88 C1500 to 91 gauge swap

[Valianze]

Hi so I’m trying to convert my truck to the newer style gauges, and I’m needing a little help as the only good guide I’ve seen to found doesn’t match my wiring in my truck. Just wanna make sure all the color for the wires go to the same things before I go ahead and try and wire in the new plug and drac module. Also where would be a good place to get a tac signal for the drac module since I know my harness doesn’t have it populated.

Thanks for the help.


Guide I’m using: Here

 

[Leeztruk]

Do you have a '92-'94 cluster, or a '90-'91 needle gauge cluster?. If you have the later version (92-94), your cluster connector isn't gonna work. If you have the earlier cluster, you just need to move a couple of wires to different locations, and add the tach wire from your coil. Also, the later cluster needs a separate DRAC module to be added to the mix, and the earlier cluster needs to have a 7 pin dip switch installed on the circuit board in place of the resisters to configure your gear ratio/tire size. The cluster with the exposed circuit board is the late version, the early cluster has sheet metal covering the circuitry. You can also see the resisters that have to be replaced

 

[arrg]

From the 1988 wiring manual:

You must be registered for see images attach

 

[Valianze]

Do you have a '92-'94 cluster, or a '90-'91 needle gauge cluster?. If you have the later version (92-94), your cluster connector isn't gonna work. If you have the earlier cluster, you just need to move a couple of wires to different locations, and add the tach wire from your coil. Also, the later cluster needs a separate DRAC module to be added to the mix, and the earlier cluster needs to have a 7 pin dip switch installed on the circuit board in place of the resisters to configure your gear ratio/tire size. The cluster with the exposed circuit board is the late version, the early cluster has sheet metal covering the circuitry. You can also see the resisters that have to be replaced

I do have the 92-94 one I just have it from a late 91 but forgot to mention that. I have the connector and drac module. I was just more needing help with the wiring since a guide I found had the connector I had but with different wiring to it and I didn’t want to go trying to color match it in case they changed the coloring and location of wires on it.

 

[Valianze]

From the 1988 wiring manual:

You must be registered for see images attach

Thank you that’s a big help! Would you know where I can find the connector diagrams for the later dash connector in the late 91-94 trucks. I’ve tried for a while searching for this and haven’t had luck any that aren’t wiring diagrams which not too great at reading.

 

[PlayingWithTBI]

Would you know where I can find the connector diagrams for the later dash connector in the late 91-94 trucks.

FWIU late 91 had the allusive tach cluster, 92 was when they switched connectors and dracs. Anyway, you may be able to find what you need here, then if wire colors don't match, just switch pin to pin. HTH
www.gmt400.com/threads/88-98-service-manuals.43575/

88-98 Service Manuals

Over the years I have collected a bunch of GM service literature. Links to PDF Scans of service and STG manuals and a links to the Parts manuals. You'll need the FREE Adobe Acrobat reader to open these files. Get it directly from Adobe here {http://get.adobe.com/reader/} If you're not...

www.gmt400.com

 

[Leeztruk]

I'm gonna throw this out there because I'm LS swapping my '89 Cheyenne in another month and am going with the '92-'94 cluster. I have a '91 needle cluster that's hard to find, and I won't be needing it. It'll be for sale, but not cheap. It'll be almost plug and play for your truck. It also has the 7 pin dip switch installed, so the speedo can be correctly set. just switch a couple of wires at the connector and add the tach wire

 

[Valianze]

From the 1988 wiring manual:

I'm gonna throw this out there because I'm LS swapping my '89 Cheyenne in another month and am going with the '92-'94 cluster. I have a '91 needle cluster that's hard to find, and I won't be needing it. It'll be for sale, but not cheap. It'll be almost plug and play for your truck. It also has the 7 pin dip switch installed, so the speedo can be correctly set. just switch a couple of wires at the connector and add the tach wire

Depending on how much you’re selling it for I’m definitely interested, I’ve been trying to find one of those for about a year.

 

[Leeztruk]

Sent you a PM

 

[DerekTheGreat]

I've got one too.

But Leeztruk's is the better option as it has the dip switches installed. I've only heard of them, have never seen them. I believe both the cluster in my truck and my spare have the "comb" looking thing installed, which I think is a one-time deal.