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Discussion Starter · #1 ·
Recently purchased a used 95 Trans Am A/T - overall runs very good. The temp gauge does not work, the fuel gauge seems to move a lot and the seller said it did not read right.

Replaced a sender in the head (grey connector) and the gauge still does not work. Runs good, and fans come on but don't want to drive without a temp gauge.

Is there a way to test the gauge with the cluster out? There is a local repair place for clusters I was going to take it to this week. Wires to the sensor and in general look good. All other cluster gauges seems to work well except for temp and fuel.

Any suggestions would be great, 94K 1 owner T/A- son bought it as his first car and he is super excited to work on it and drive it. Happy to have a LT1 - and upgrading it more as we can.

Thanks in advance for any suggestions of how to address the temp gauge issue.

Toby
 

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Download the 95 factory service manual at the following link. In the section 8 instrument cluster wiring diagrams, will be test charts for all instruments. www.mediafire.com/?40mfgeoe4ctti

The process of checking the gauge involves taking the wire off the sender. Then with ignition switch on, touch wire to a good ground. Here's where I forgot weather touching wire to ground moves gauge needle to low or hot temp on gauge.

In the test charts for gauge sender, the manual should list the resistance that sender has at a specific temp. By using resistors of the same value, placed on end of wire to sender, you should be able to drive the gauge needle to those temp readings on gauge.

Fuel reading is usually off on GM gauges of the period. On my 90, gauge reads full for about 100 miles. Then drops down to about 1/2. It then drops down normally.
 

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Discussion Starter · #4 ·
Thank you I will work on that

if there is an issue with the temp gauge can they be purchased and put in the cluster or do you have to send it out or have it repaired?
 

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Individual gauges are not available to the general public. Your choices would be to swap cluster, buy an aftermarket gauge & sender, or try to find someone on ebay or craigslist that will sell the coolant temp gauge by itself.
 

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Discussion Starter · #6 ·
got it fingers crossed a repair is available it will be tested this week and I will update

Thanks,

Toby
 

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Discussion Starter · #7 ·
small update - cluster checked out good, tried to ground the lead and the wire leading to it (close to sensor) and does not move the cluster.

I was thinking to try and check it at a section that is closer to the cluster. Is there a good place to tap into that wire? I was planning on looking for the green wire in the harness as it was leading into the firewall towards the driver side. Is that a good idea or is there a better place to track it?

Thanks,

Toby
 

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I know this is a goofy question to ask,but, did you have ignition switch on when you test the wire?

Was the wire you tested dark green? If no, you have wrong wire. Did you make sure ground was good where testing wire? To test ground, get a 2 lead test light. Connect 1 lead to battery positive terminal. Ground 2nd lead to engine block. If ground good test light lights up.

With ignition on, when dark green wire pulled off of sender does gauge move to fully cold position? If yes, sender is bad. If no dark green wire from sender to gauge has a short.

Dark green wire connects to instrument cluster at connector A cavity 17. Theres a diagram of connector on page 8A-81-5 of 95 service manual. In fact section 8A-81 gives chapter & verse on cluster.

I suggest running a test wire from sender to instrument cluster connector A cavity 17. This will involve pulling cluster out of car, cutting dark green wire going to cavity 17, several inches from connector. Attach test wire to cut dark green wire. Install cluster and see if gauge works correctly.

If yes, get some dark green wire to make new gauge to sensor wire. Run it through firewall and up to cluster connector. Don't forget to insulate splice you've made.

If no, attach original dark green wire and insulate.
 
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