mike...
80 fuel gauge
Thread Starter
7th Gear
Joined: May 2010
Posts: 7
Likes: 0
80 fuel gauge
I bought a 1980 last year in April and can't get the fuel gauge to read more than 1/4 tank. I tested the Gauge itself and it works the whole way up to full, I took the gauge panel out and everything seemed ok with the flex circuit board, I tested the sending unit and got some wacky readings so I replaced it to no avail. Any ideas?
Thread Starter
7th Gear
Joined: May 2010
Posts: 7
Likes: 0
I ran an auxiliary ground wire direct from the gnd terminal of the sending unit to the negative battery terminal and the gauge reads the same, 1/4 full. The Corvette shop manual says the tank unit feed wire voltage should be 3-4 volts, I have 6.68 volts!
I am working on checking this willcox thing but I have to e-mail them as far as I can figure...
I am working on checking this willcox thing but I have to e-mail them as far as I can figure...
Thread Starter
7th Gear
Joined: May 2010
Posts: 7
Likes: 0
I did pull the wire off and gauge goes to full, (both feed wire and gnd wire) same result.
I ran another ground wire to a good ground and still nothing. (Sending unit is new)
I'm going to look again at the ground nuts on the back of the gauge, I think I may have a bad ground there, thanks for your help!
I ran another ground wire to a good ground and still nothing. (Sending unit is new)
I'm going to look again at the ground nuts on the back of the gauge, I think I may have a bad ground there, thanks for your help!
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Thread Starter
7th Gear
Joined: May 2010
Posts: 7
Likes: 0
As a matter of fact, I have had the gauge cluster out twice already and I did see this resistor, it seems to be in tact but I am thinking of checking it further or having it checked out. I also want to check the ground nuts on the fuel gauge itself so I am hoping to work on that on Monday.
Thanks again...
Thanks again...
Former Vendor
Joined: Aug 2006
Posts: 76,656
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From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
Your symptoms sure sound like the resistor on the gauge.
If the resistor is bad on the back of the fuel gauge, the highest reading it can make is slightly above 1/4 tank and this is only with a full tank of fuel. Check the resistor and if it is bad you'll need a 90 ohm to replace it.
The porcelain resistor is not available new or used but you can purchase a regular resistor from an electronics store and solder some loop ends on it. It will work just fine.
Willcox
If the resistor is bad on the back of the fuel gauge, the highest reading it can make is slightly above 1/4 tank and this is only with a full tank of fuel. Check the resistor and if it is bad you'll need a 90 ohm to replace it.
The porcelain resistor is not available new or used but you can purchase a regular resistor from an electronics store and solder some loop ends on it. It will work just fine.
Willcox
Last edited by Willcox Corvette; May 30, 2010 at 06:22 PM.