imvettecrazy

On the way to the Carlisle Corvette rally my alternator was pulling so much current (headlights on, heater on) that it made the belt slip and not turn the water pump. It was so bad that I had to disconnect the alt and get back home on the battery. Made the 25 mile trip home but on the way the gas gauge and Temp gauge froze in place, fuel gauge shows 1/2 tank, Temp gauge shows 180. I never heard of this happing before. Anybody had a problem like this?

Also after putting a new alt and fan belt it's not charging now!!!

Thanks
Larry D.

0Willcox Corvette

Did you check the gauges fuse? Normally if it's a wire or grounded problem the gauges would go to one side or the other.

Willcox

imvettecrazy

Fuses are ok, I checked the grounds best I could. After it cooled down it still shows 180. I took a yard stick and moved the fuel float and the gauge doesn't move, froze at a little less than 1/2 tank. Sending unit wires are ok. Electrical problems are such a PITA!!!

How can disconnecting the alternator and driving 25 miles home make the gauges freeze up???

Larry D

0Willcox Corvette

My next step would be to reach (and I know it's a pain) up behind the dash and un-plug the fuel gauge. The test the two terminals for power and ground.

Fuel gauges for your car react in the same manner as a C3 that have a "Known" issue have the following symtoms as show below. Your issue doesn't fit any of these issues which leads me to the connector. Test for power to the gauge first using an alternate ground. If you have power then use the ground terminal on the connector and test the power again. If you don't have it then the ground is the issue, if you do have it then you have a gauge issue.

You could pull the ohms wire off the sender and with the key on see what the gauge does, it should go to full. If it does then ground it out and it should go to empty as shown below. I'm concentrating only on the fuel gauge because I feel as if both are connected.



Here is a simple schematic for the fuel gauge.



Willcox

DUB

Ok...I will 'jump' into this hornets nest and ask some questions and hopefully I do not get badly stung for asking them.

How do you know it was 'pulling so much current???

Was it because your ammeter was all the way on the + side???

or was it because the alternator was seizing up and making the belt squeal and smoke???

Did you check your GAUGES fuse with a volt meter??? Reason I ask is simply taking out the fuse and looking at it means nothing. Using a volt meter and checking to make sure that you have 12 volts on the terminals that hold the fuse in is what you are looking for. And hits is due to dirt and corrosion that can develop on the terminals in your fuse panel that can either drop the voltage or make it not allow voltage to flow at all.

It can also be your voltage regulator.

And posting what year you are referring to would also be helpful so I can pull out the wring diagram and look at it... or if you car has been modified from the original design. I just do not know.

I can say for a fact...that your TEMP gauge and FUEL gauge BOTH have the same similar wiring to them. EACH of them take a 12 volt fused power wire....a GROUND wire and a signal wire from the senders.

You ammeter gauge is different...and if it is not moving...that is why I do not want to assume which year it is and honestly...I work on so many eras of Corvettes....I assume nothing any more and refer to wiring schematics because my brain can not remember everything from the beginning to a 2016 Corvette.

Unless you also used an ohmmeter and checked the signal wire from your fuel sender and verify that you can get from 0 to 90 ohms ( or there about)....just looking at them is also a guess.

I would VERIFY battery voltage at each gauge and then go from there.

DUB

65GGvert

Do your parking brake indicator light and backup lights still work?

JeffR*

Pls clarify/confirm..... 65 convert. I am having a similar problem but I have the Black/Pink wire to the "I" and the Tan to the "S" connectors at the sending unit. They seem to be pin size specific so they can't be connected wrong?