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Discussion Starter #1
Just installed my gauges on my SS back into the car. Been apart for 3 years. Can't recall if they worked when I took it apart as I disassembled the entire car right after purchase.

Both the fuel and temp gauge needles don't move at all. Lets troubleshoot them separately.
1. Fuel gauge-- The needle sits on E and doesn't move under any circumstance. It has about 3 gallons of gas in a new tank I installed a few weeks ago. Should read almost a quarter tank. The ground wire on the sending unit is good. I tested it by running a jumper right from the positive battery post to my test light and then I touched the probe to ground and get a bright lite wherever I touch it, on the tank, the strap, the frame and the wire leading from sending unit to the body ground screw, which I sandblasted clean before screwing. I pulled the tan wire off and checked the gauge. It still doesn't move off E. I thought it should, from reading other posts. Anyway, I tested the tan wire at the sending unit once I pulled it off with my test lite and it carries a bit of voltage in that it lights my test lite dimmly even tho I have a good ground jumper to the neg battery post. SOOOO, is it the gauge. Any more tests to do?

2. Temp gauge. The needle sits way above the H side, basically out of view. Never moved in all my tests. Heres what I checked so far. Pulled connected off gauge under the dash. The black and pink wire has power, it will lite a test lite. The green wire didn't connect me to ground so I pulled the clip off the sending unit at the intake manifold and grounded the green wire from there to battery neg. Still no change, needle wont move.
I have a good ground to the gauge pod generally, as my clock runs perfectly and my dash lite all work. I actually connected a jumper from one screw on the gauge pod directly to the battery negative to double check this. NO changes to anything. WHAT TO DO NEXT?
 

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The gas gage should only have a 2 wire plug on it. One is the pink (12 volts) the other a tan (sender). The gage gets a ground from the gage frame. Try grounding the rear gas gage frame with a jumper wire and see if the gage responds.
 

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Discussion Starter #3
John, when you say ground the gauge frame, do you mean clip a ground to one of the screws holding the gauge to the metal pod. Its a bit tight to get there but I'll try that. But should I have the tan wire off the sender at the tank when I do this? I believe that if the tan wire is off the sender at tank the fuel gauge needle should jump to full,am I right?
I am thinking of pulling the entire cluster out of the car again. Is there a test I can do of the gauge itself on the bench to see if it works?
 

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Here are some links to help you trouble shoot your fuel gauge.
http://www.chevelles.com/techref/tecref18.html

This process can be applied to all recent GM cars except those with computerized gauges.

1) Locate the fuel sender feed wire near the fuel tank. You're looking for a single tan colored wire. With the tan wire disconnected at the fuel tank, the fuel gauge should read past full with the ignition on. Wait a few moments as some fuel gauges take a long time to respond. Touch the tan wire from the body to any convenient ground and the gauge should read empty. If not, you have a wiring problem or a bad gauge.

2) If the gauge responds correctly, the gauge and wiring are OK. Next use a multi-meter to measure resistance to ground of the sender wire connection on the top of the fuel sender or the tan wire from the top of the fuel tank. Measurements should track the fuel in tank.

Full - 84-88 ohms
Half - 40 ohms, give or take
Empty - 0-2 ohms

If this doesn't check, then sender or wiring on top of the tank is bad or the sender not adequately grounded. Senders are typically grounded by a black wire which is welded to the sender and attached to the body with a sheet metal screw.

3) If the sender checks OK but gauge and wiring don't, clean the connections, reconnect the sender wiring and separate the Fisher connector (located just outboard of the fuse block under the dash). The gauge should then read past full. Ground the tan wire in the dash side of the Fisher connector and the gauge should read empty. If not, you probably have a bad gauge or possibly a dash wiring problem. Go to Step 5.

4) If the gauge checks OK, then make the same resistance checks to the tan wire in the body side of the Fisher connector. If the readings are different than those at the sender, body wiring has a problem and requires detailed inspection. If they look OK, then the Fisher connector is probably dirty.

5) Clean and reconnect Fisher connector, pull the connector off the back of the gauge and make the same resistance checks to the tan wire. If they don't check, you have a dash wiring problem. If they check OK, your gauge is bad. Gauges can be bench-checked but this is best left to a specialist.


Rocky
 

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Discussion Starter #7
well, my checks tell me that the dash gauge isn't working. It never moved during any test, needle froze in same position. So I removed the gauge cluster from the car and removed the fuel gauge. I see windings and thin wires. The needle seemed to be stuck in the one position, but I nudged it over a bit now. Has anyone done any testing on the bench? Seems to me that if I ground the gauge housing, and put power to the tang that had the pink wire, with no tan wire connected, the gauge should move to full position. Am I right? any other thoughts about testing on the bench? I read that Year One has a rebuid service at 85 bucks a gauge, then I'll have ship cost also. Any other alternatives?
 

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Yes you are right. 12 volts to the gage, ground to the frame, tan disconnected, the gage should go super full.
 
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