PDA

View Full Version : Fuel Gauge Issue


87MCProstar
07-20-2013, 10:58 PM
Hey All, quick question about fuel gauge. It's not working, but I'm getting 4.5V at connector but nothing on the posts of sender itself. What could be issue? Bad sender unit or gauge?

mikeg205
07-20-2013, 11:01 PM
most likely sender... sender at www.isspro.com.... pull out sender - check resistance across sending unit connections.

JimN
07-20-2013, 11:42 PM
Hey All, quick question about fuel gauge. It's not working, but I'm getting 4.5V at connector but nothing on the posts of sender itself. What could be issue? Bad sender unit or gauge?

Turn the key to ON and connect the pink wire to the black. If it doesn't do anything, connect the two at the gauge. If it still doesn't do anything, it would indicate the gauge has a problem, but you would want to verify the ground connection and the pink wire's voltage.

If it pegs the needle, your sender is bad. Do a visual inspection- if the terminals look corroded, replace them by crimping and soldering the new ones.

j.mccreight@hotmail.com
07-20-2013, 11:59 PM
Hey All, quick question about fuel gauge. It's not working, but I'm getting 4.5V at connector but nothing on the posts of sender itself. What could be issue? Bad sender unit or gauge?

You should not have "voltage" on the fuel sender signal "S" wire, the only wire that should have 12v is the "I" post of gauge with key on and ground on the ground post with key "on", the sender should be ohm resistance. On the sender itself should have 2 wires, a ground and a signal which the gauge measures resistance of this wire. with key "on" if you take a jumper wire and touch the ground and signal wire the gauge should peg past full if it doesn't you have a wire or gauge issue, if you disconnect the signal wire from the sender the gauge should stay past empty. If you know how much fuel is in the tank the next test will be beneficial. Take your dvom set on ohms with key "on" put black lead on ground post and and red lead on signal post, read ohm value. Values are approximate, 240 ohms is empty, 109 ohms is half tank, 33 ohms is full tank. You can remove sender and manually operate float and check ohm readings. to isolate wire issue do all the tests again this time at the gauge and compare. This should help you diagnosis your problem.

squiggy33slc
07-29-2013, 12:43 PM
Ok I have a simple question.. I pulled my tank, before the winter to clean it out and thought I would remember where the wires went for the fuel gauge, but cant remember where the black (think it is the ground) wire was attached back at the tank. Should of taken a pic before removal
I have an 1988 prostar 190.

If I put all the wires on the post and turn the key on it pegs it full.

Any help would be great..