View Full Version : Fuel Gauge


JADHHJR
Jul 2nd, 02, 05:49 AM
My gauge goes way past full dont mater if the sending unit is hooked up or not it does nothing but stay pegged way past full.
Do you guys think it's time for a new gauge??
149.00 is alot of money.
Already replaced the sending unit nad gas tank.
Also the ground wire from the tank is fine.
On the back of the fuel gauge I have 3 prongs for the gauge to plug into and one with a nut on it is this for a ground or what?
I checked the prongs with a test light on the one I have very bright test light on the other one I get a dim light and on the top one I have no light.
Please help me am going crazy with this freaking thing.
69 LM1 Thanks,
John

Mark C
Jul 2nd, 02, 07:53 AM
Bottom terminal is a ground. If it doesn't ground to a metal plate (like the console mounted gauge cluster) then you need a separate ground wire.

One terminal is +12V in to the gauge
One terminal is connected to the sender, and the third terminal is ground. There is also a 49 ohm ( I think) resistor across the back of the guage mounted to the two terminals that are directly across from each other.

What year car and which guage is it, dash or console mounted. If you have the console mounted gauges, make sure there is a ground connection between BOTH metal guage mounting plates, and between one of the plates and ground.


------------------
Mark Canning
1969 Indy Pace Car
350/300HP RPO Z11
My 69 L48 - 350/300HP Engine (http://www.townisp.com/~markcanning/camaro/transparent%20air%20cleaner3.jpg)

JADHHJR
Jul 2nd, 02, 10:01 AM
Mark I have a dash mounted fuel gauge.
So I need to make my own ground wire to the back of the gauge?
Thanks,
John

JADHHJR
Jul 2nd, 02, 10:02 AM
Also it is a 69 Camaro LM1

stingr69
Jul 2nd, 02, 11:47 AM
The default position for a fuel gauge is way over on the full side. Disconnect the sending unit at the trunk plug. Run a jumper wire from the harness side (not the sending unit side) to ground and watch through the rear window at the gas gauge with the power on. It should drop to empty with the jumper going to ground. If it does not, you have an open circuit between the gauge and the back of the car.

If it does go to empty you need to recheck the sending unit and or the ground wire connection.

The sending unit is a variable resistance. Very low ohms at empty between the sending unit side of the harness to ground. Much higher resitance at full tank.

-Mark.

sixt9d
Jul 2nd, 02, 06:52 PM
I had the same thing go wrong with my gauge...I changed the shunt resistor (little ceramic thing in back of gauge with a bunch of wires wrapped around it)and it worked...$6.00 from ricks.

JADHHJR
Jul 2nd, 02, 08:44 PM
Do you mean in Ricks catalog??
What page is it on?
Hell for six bucks it is cheaper than 149
Thanks,
John

This is the greatest Camaro site on the net!
69 LM1

sixt9d
Jul 3rd, 02, 02:57 PM
Ricks/firstgen.
page 100
item # cg-13 fuel gauge resistor...$6.95
I too almost shelled out $$$$ for a gauge but a local speedo shop gave me that little tip....good luck hope it fixes your problem.

[This message has been edited by sixt9d (edited 07-03-2002).]

JADHHJR
Jul 13th, 02, 07:41 PM
Guys thanks for the help with my fuel gauge.
I got it fixed I ordered a resitor from Rick's but come to find out is was not needed it was the fuel sending unit wire that was bad.
Work's great now.
Best Camaro site on the Web.
Thanks,
John
69 LM1