Gas Gauge Above Full

Topic: Gas Gauge Above Full (Read 2754 times) previous topic - next topic

Gas Gauge Above Full

Reply #15 – December 16, 2008, 11:30:29 PM

I would check the readings to make sure it's not a wiring issue first.
check at the dash and right at the sender.

Gas Gauge Above Full

Reply #16 – December 17, 2008, 05:38:48 PM

After checking the wiring and the gauge seem to be fine. I would think this would mean the sending unit it bad. I've talked to ford and i've loooked aftermarket, I seem to come up with nothing. Everything seems to be a eihter a joint fuel pump and sending unit, or they just don't know the difference between them.

I may still be able to get the full digital sending unit from Ford, the dealership that its allegedly at was closed by the time i got the infor about them.

Gas Gauge Above Full

Reply #17 – December 17, 2008, 06:07:17 PM

Sounds like it's time to see if Vinnie has one.

Gas Gauge Above Full

Reply #18 – December 17, 2008, 06:23:09 PM

Alright well I thought you had a way to convert one to the other. Seeing I already have the full digital sending unit out of my parts car...

Gas Gauge Above Full

Reply #19 – December 17, 2008, 06:49:01 PM

How are you with electronics and soldering?

Gas Gauge Above Full

Reply #20 – December 17, 2008, 07:43:28 PM

Well i soldered the jumper wire in my cluster, and a handful of wires on my engine harness to weatherproof them. As far as electronics I'm not sure what you mean, but with instructions I'm fully capable of learning and trying something new in order to reap the benefits of having a gas gauge again.

Gas Gauge Above Full

Reply #21 – December 19, 2008, 01:40:29 AM

lay on your back under the tank
look to the right
find a two wire harness
one wire is yellow / white
the other is likely black.
this should be the sender harness

grab harness and follow its path up
it should be going up and finally under your package shelf in the trunk
package shelf-in trunk up near speakers (connector c491)

get in trunk
look for a connector with yellow white wire and a black
unhook connector
one end goes to your dash guage
the other goes to the sender

disconnect sender connector
connect red meter lead to the yellow white
connect black meter lead directly to the metal tank***
do not deviate from the above two steps or reading may be wrong
set meter to resistance and read
jot down that number you get
add 5gal of gas
read sender
jot down that number

if there is a change then the sender is assumed to be good.

To test the guage, insert a paper clip in the connector (C491)
turn on key
gas needle will peg if its good
gas needle will peg if its a conventional cluster
gas needle will go to empty if its a digital cluster sender

go to my diy link below for details.
you will find a link here to "guages" with wiring diagrams.
go to my electrical tech sticky "1987 evtm" page 129 for wiring diagram.
post your results

You can define what sender you have based on your readings as well as determin if it works.

I have often thought that if one puts a digital cluster sender in a conventional dash car, the leads on the guage can be flipped there to compensate for the tank circuit,,,,,,,,,,(you getting this daminc?)

Gas Gauge Above Full

Reply #22 – December 19, 2008, 01:57:46 AM

If i get what your saying here,,,,,,,,,
you are saying you have installed a digital dash sender?
If this is the case then you must have a full tank of gas already,,,correct?
if so, everything is fine, your sender is just opposite.
I dont see how you had it working fine with a digi sender then all of a sudden things went wacky.
with a digi sender connected to a conventional cluster, things should have been opposite all the time.

if so,,,,,
disconnect C491 connector in the trunk near speakers
this is the yellow / white with black wire
jumper your yellow white wire to your black black wire
jumper your black to your yellow white

turn on key

see what happens

Gas Gauge Above Full

Reply #23 – December 19, 2008, 12:51:23 PM

Jcassity, thanks for the info.

I have a normal sending unit installed in the car right now. But I have a full digital sender out of my parts car that I was curious to see if it worked.

Gas Gauge Above Full

Reply #24 – December 22, 2008, 03:36:34 AM

Quote from: jpc647;248149

Jcassity, thanks for the info.

I have a normal sending unit installed in the car right now. But I have a full digital sender out of my parts car that I was curious to see if it worked.

Why bother? you need to verify what you got works first.

Gas Gauge Above Full

Reply #25 – December 22, 2008, 02:14:27 PM

Where is connector c491? I'm looking in my EVTM for 1988 and can see it. But I'm unable to tell where it is in the car, its before the gauge, but im not sure where.

Gas Gauge Above Full

Reply #26 – December 22, 2008, 07:35:30 PM

Quote from: jpc647;248504

Where is connector c491? I'm looking in my EVTM for 1988 and can see it. But I'm unable to tell where it is in the car, its before the gauge, but im not sure where.

If you look ahead another page or two it will tell you where the connectors are located.

Gas Gauge Above Full

Reply #27 – December 23, 2008, 01:14:39 AM

Quote from: jcassity;248106

grab harness and follow its path up
it should be going up and finally under your package shelf in the trunk
package shelf-in trunk up near speakers (connector c491)

Gas Gauge Above Full

Reply #28 – January 03, 2009, 11:17:57 AM

Jcassity
When you gave me instructions how to test the sending unit you told me to ground the meter to the metal tank. Why is that? I'm curious what the difference is if I ground it to the tank or anywhere else.

Gas Gauge Above Full

Reply #29 – January 03, 2009, 11:46:12 AM

The grounding pin on the connector is the same as grounding it to the tank, but takes the grounding pin out of the trouble shooting. Any bare metal spot, or around the sending unit ring will work on the tank.
What parts have you tested so far?
I would start with the sender it's self, then the wiring, then the dash stuff.