Both gas gauges are not working properly reading and stuck on full

1987 GMC SIERRA
83,000 MILES • 5.0L • V8 • 2WD • AUTOMATIC
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MARCUSMADRIGALES13
  • MEMBER
  • 9 POSTS
We don’t know if it’s a ground wire or what but when I switch gas tanks on either tank my gauge always reads full and I don’t seem to know how to fix it.
Apr 6, 2021 at 4:58 PM
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KASEKENNY
  • ✓Experienced Mechanic
  • 18,907 POSTS
I am sure this issue is a gauge but I attached the testing below for what we need to do to prove this out.

Also, here is a video on how to replace the cluster on a Yukon that is similar. However, this is a newer truck so it may not help you but it may help others that visit this page with a similar issue.

https://youtu.be/_HEC44xENxw

This testing below is for your vehicle so let's run through this and see what turns up. Thanks
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Apr 8, 2021 at 8:45 AM
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