Help needed: Fuel sending unit

Topic: Help needed: Fuel sending unit (Read 9859 times) previous topic - next topic

Help needed: Fuel sending unit

Reply #15 – September 28, 2007, 05:03:22 PM

Quote from: daboss351;179266

relay is on the firewall on the drivers side.

can anyone confirm this about a relay for the fuel sending unit/gauge?

Help needed: Fuel sending unit

Reply #16 – September 28, 2007, 09:25:40 PM

anyone?

Help needed: Fuel sending unit

Reply #17 – September 28, 2007, 11:03:08 PM

I can.... I KNOW it is. My dads came loose and wouldnt kick on the pump till be pulled it and put it back in. I just dont know which of the 2 it is

Help needed: Fuel sending unit

Reply #18 – September 28, 2007, 11:17:21 PM

would one from an '87 XR7 work? I got one sitting here, and yes it's rusty on top.

Help needed: Fuel sending unit

Reply #19 – September 29, 2007, 10:57:52 AM

Quote from: daboss351;179537

I can.... I KNOW it is. My dads came loose and wouldnt kick on the pump till be pulled it and put it back in. I just dont know which of the 2 it is

my pump is running but the fuel guage isnt working... and this is what I am trying to figure out.

Help needed: Fuel sending unit

Reply #20 – September 29, 2007, 11:45:15 AM

see 3.8, 5.0 and 2.3 configurations on the 87evtm

pull up you pm and do the resistor test for the guage.
use your meter and check for the resistance value on the connector leading to the sender. your gonna have to remember how much gas you think is in the tank. just measure the resistance at the connector c491 under the package shelf and report back.

Help needed: Fuel sending unit

Reply #21 – September 30, 2007, 07:11:21 PM

apon doing those tests, when I did the resistor test the needle did not move. when I used my ohm meter on the tank side of the plug I got a reading of 82.5. I am thinking that the problem is in the guage it self so I am back out to do more taking apart. I will find this problem and fix it.....

Help needed: Fuel sending unit

Reply #22 – September 30, 2007, 09:36:54 PM

well after taking the dash apart and finding nothing wrong I am starting to think that my float is stuck. when I was doing the testing at the plug in the trunk I tested the yellow wire with my test light and it was blinking... I dont know if there is supposed to be steady voltage there or if it was supposed to be doing that. so now I guess I am looking for a new sending unit :(

Help needed: Fuel sending unit

Reply #23 – October 01, 2007, 04:54:26 PM

Help needed: Fuel sending unit

Reply #24 – October 02, 2007, 02:29:41 AM

Quote

tested the yellow wire with my test light and it was blinking

Correct. As you can see in the first diagram Jcassity posted above, the sender grounds the gauge, which gets its power from the Instrument Voltage Regulator, which provides a "fake" 5v by pulsing the 12v input. Ground the yellow wire at the tank's plug, and the gauge should quickly swing right up past "full".

Help needed: Fuel sending unit

Reply #25 – March 14, 2014, 08:12:02 PM

Quote from: MasterBlaster;180172

Correct. As you can see in the first diagram Jcassity posted above, the sender grounds the gauge, which gets its power from the Instrument Voltage Regulator, which provides a "fake" 5v by pulsing the 12v input. Ground the yellow wire at the tank's plug, and the gauge should quickly swing right up past "full".

bump..

So to check the gauge you just need to not have the plug connected and run a jumper from the yellow wire to a ground but leave the other in the sender? That should send it to full?