LS swap with 91 suburban gauges

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eskimomann209

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I have the wiring repinned to run the 91 instrument clusters but the speedo isn’t responding.
I checked continuity to the pin on the ECU and it’s good there but the speedo refuses to move.
My ECU knows the speed, it updates my phone through the OBD2 port.
I’d really just like the speedo to work now.
It’s sweet because this is the first time the GAS gauge is correct and now of course my speedo is being an ass.
 

eskimomann209

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Checked at the back of the cluster and it seems the speedometer module is getting everything it needs
Ground, 12v and the signal
Gotta be a bad speedo
Juuuust my luck
 
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eskimomann209

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Turns out it was indeed the speedometer that was the issue. I went to pick n pull happened to find a 91 GMC ventura.
Speedometer was the same. Quick swap of the face plate and wham-o. Have completely functioning gauges.
Picture is a little blurry but it woooorks.
 

eskimomann209

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Null

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Frank albrecht

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Checked at the back of the cluster and it seems the speedometer module is getting everything it needs
Ground, 12v and the signal
Gotta be a bad speedo
Juuuust my luck
Let’s see the motor area. I just did a LS swap in my 86
 

eskimomann209

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Let’s see the motor area. I just did a LS swap in my 86
It’s a little dark out. One of my other threads have pics of the truck during the “build”. Still have a lot left to go but I drive her daily so I take baby stepz
 

Frank albrecht

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It’s a little dark out. One of my other threads have pics of the truck during the “build”. Still have a lot left to go but I drive her daily so I take baby stepz
Nice these trucks are a ton of fun! I’m finishing up my swap just waiting on fuel cell....

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RoryH19

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My 90 burb speedo also died after work for a bit. Was able to have one shipped to me from a salvage yard. So far so good.

I see you went turbo. After installing the 6.0 and surrounding acc. I wouldn't be able to fit one. Plus the A/C compressor needs a place to live.
Any idea on the power?

Here's my project thread:
https://www.gmsquarebody.com/posts/514921/
 

Frank albrecht

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I’m thinking around 550... not really sure tho to be honest... time will tell
 

eskimomann209

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Nice these trucks are a ton of fun! I’m finishing up my swap just waiting on fuel cell....

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Why didn’t you do the fuel pump swap and the standard 87 truck fuel tank
 

climb-101

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nice, i’m doing he same swap without the turbo though. i’m just working on swapping gauges. did you just connect the wire from the PCM to the cluster.

also what OBD2 thing are you using to check it on your phone?
 

eskimomann209

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nice, i’m doing he same swap without the turbo though. i’m just working on swapping gauges. did you just connect the wire from the PCM to the cluster.

also what OBD2 thing are you using to check it on your phone?
Yes I did. I can remember which pin it was but it was similar in color and position to the ac relay so be careful when playing around in there.
I grabbed a cheap one from amazon
It works well for all the info you’d need.
Wiring is still roughed in I plan on re looming everything and heat shrink and soldering all connections

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eskimomann209

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Officer:
Son do you have ANY idea how fast you were going??
Me:
Couldnt have been more than 85 officer

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LateOnTheBrakes

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Where did you get the info to swap your gauges around? I have the dash from a CUCV and I want to swap to the similar gauge setup you have. I bought a spare gauge cluster. I don't know if I should move the fuel, oil pressure, water temp, and alternator info over or swap the whole gauge cluster.

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