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Gas guage blues

  • Thread starter Thread starter stephen4785
  • Start date Start date Dec 2, 2004

stephen4785

New Member
Dec 14, 2003
321
0
0
Fort Worth Texas
Dec 2, 2004
#1
  • Dec 2, 2004
  • #1
My gas gauge hasnt worked since I bought my car. Im pretty sure its the sending unit but how do I check to see if it is or not?
 

allcarfan

The Answer Man
Founding Member
Apr 8, 2001
2,458
1
56
North Atlanta
Dec 2, 2004
#2
  • Dec 2, 2004
  • #2
you can take the wires off the sending unit, ground the one and run a hot wire to the other and see if your guage 'pegs' to F. You may just have to ground one wire off the sending unit. Thats the best way to check. I THINK I described that right. A sending unit isnt that much either. I got one for about $35 with a bronze float and a new ring.
 
F

ForceFed70

That's why they call it "dope"
Founding Member
Dec 6, 1999
4,818
1
69
BC Canada
Dec 2, 2004
#3
  • Dec 2, 2004
  • #3
Take the wire going to the sending unit and ground it out.

With the key on, the guage should max out. If it does, then it's the sending unit that's the problem. If it doesn't... then it's something else.

Don't mess with any hot wires during this test or else your testing more than just the sending unit.

*Note* There should only be 1 wire going to your sending unit.
 

WORTH

20+ Year Stangneter
Nov 18, 2002
2,166
44
98
Cape Cod, Ma.
Dec 2, 2004
#4
  • Dec 2, 2004
  • #4
allcarfan said:
you can take the wires off the sending unit, ground the one and run a hot wire to the other and see if your guage 'pegs' to F. You may just have to ground one wire off the sending unit. Thats the best way to check. I THINK I described that right. A sending unit isnt that much either. I got one for about $35 with a bronze float and a new ring.
Click to expand...

You've been into the pot today haven't ya??
 

allcarfan

The Answer Man
Founding Member
Apr 8, 2001
2,458
1
56
North Atlanta
Dec 2, 2004
#5
  • Dec 2, 2004
  • #5
I was close....haha. I should have just said....

while your gas is draining, see if you can get a spark from a hot wire by dragging it along your frame rail.

Its been a long few weeks, what can I say?
 

WORTH

20+ Year Stangneter
Nov 18, 2002
2,166
44
98
Cape Cod, Ma.
Dec 2, 2004
#6
  • Dec 2, 2004
  • #6
allcarfan said:
I was close....haha. I should have just said....

while your gas is draining, see if you can get a spark from a hot wire by dragging it along your frame rail.

Its been a long few weeks, what can I say?
Click to expand...

Well stop dragging ass and do my instrument bezel, I'm gonna need that by the end of the year..............................2005
 
6

68Coupe289

Founding Member
Sep 13, 2002
234
0
0
Lexington, KY
Dec 2, 2004
#7
  • Dec 2, 2004
  • #7
Does the tank have to be pulled to replace the sending unit?
 

65fastback2+2

New Member
Aug 4, 2003
1,229
0
0
Louisville, KY
Dec 2, 2004
#8
  • Dec 2, 2004
  • #8
68Coupe289 said:
Does the tank have to be pulled to replace the sending unit?
Click to expand...

nope, but you will want to make sure to drain the gas, the sending unit is at the bottom of the tank facing the driver side.
 
S

SLEEPERstang21

Founding Member
Feb 15, 2002
204
0
0
Sunny California
Dec 2, 2004
#9
  • Dec 2, 2004
  • #9
hey i hav the same problem i changed my sending unit but it stil acts the same. the gas gauge still moves but it only goes half full when i have a full tank.
 
F

ForceFed70

That's why they call it "dope"
Founding Member
Dec 6, 1999
4,818
1
69
BC Canada
Dec 2, 2004
#10
  • Dec 2, 2004
  • #10
SLEEPERstang21 said:
hey i hav the same problem i changed my sending unit but it stil acts the same. the gas gauge still moves but it only goes half full when i have a full tank.
Click to expand...

The rest of your guages work normal?
 

Cobain03

Active Member
Aug 27, 2003
996
0
36
Lexington, Ky
Dec 2, 2004
#11
  • Dec 2, 2004
  • #11
if you still have the orginal gas tank, may want to consider replacing it. my gauge read 1/2 tank while sitting on empty. ha ha i was getting about 30 miles to the gallon untill i changed the sending unit.

a gas tank with a drain plug is like 75 bux at my dealer...
www.docsmustang.com
 
S

SLEEPERstang21

Founding Member
Feb 15, 2002
204
0
0
Sunny California
Dec 2, 2004
#12
  • Dec 2, 2004
  • #12
yea they seem fine and working
 

burnout289

Founding Member
Jan 3, 2002
1,000
0
36
sun diego
Dec 2, 2004
#13
  • Dec 2, 2004
  • #13
I remember when I was posting about this problem [ages ago] someone replied that they gixed theirs by replacing that ring that holds the sending unit on. not sure why that would work, unless it helps grounding.... just a thought.
 

WORTH

20+ Year Stangneter
Nov 18, 2002
2,166
44
98
Cape Cod, Ma.
Dec 3, 2004
#14
  • Dec 3, 2004
  • #14
SLEEPERstang21 said:
yea they seem fine and working
Click to expand...

first make sure you have a good ground. Clean a place on teh sender and a place on the frame and run a jumper wire. See if that fixes it, if not the sender may be out of adjustment,

if you check the ground and still have the problem, tell me where the guage reads when it is full, and where it reads when it is empty , and I will tell you how to adjust it.
 
6

68Coupe289

Founding Member
Sep 13, 2002
234
0
0
Lexington, KY
Dec 3, 2004
#15
  • Dec 3, 2004
  • #15
Cobain03 said:
if you still have the orginal gas tank, may want to consider replacing it. my gauge read 1/2 tank while sitting on empty. ha ha i was getting about 30 miles to the gallon untill i changed the sending unit.

a gas tank with a drain plug is like 75 bux at my dealer...
www.docsmustang.com
Click to expand...

Docs Mustang Parts is right down the street from me.
 

stephen4785

New Member
Dec 14, 2003
321
0
0
Fort Worth Texas
Dec 3, 2004
#16
  • Dec 3, 2004
  • #16
well Iv got a new tank and a new ring and o-ring. I should have replaced it when I replaced the tank but I replaced it before the car was running so I couldnt tell if it was broke or not untill I drove it and filled it up. Thanks for the info. Ill try it this weekend to see if its the unit or not. Im thinking about just cutting a hole in the top of the tank and putting a wood stick down inside so that way all I have to do is pull it out to see how much gas I have left.
 

Pakrat

Founding Member
Aug 6, 2000
3,843
0
56
Currently: NH Originally: Rhode Island (and all po
Dec 3, 2004
#17
  • Dec 3, 2004
  • #17
WORTH said:
You've been into the pot today haven't ya??
Click to expand...

Not that there's anything wrong with that.
 
S

SLEEPERstang21

Founding Member
Feb 15, 2002
204
0
0
Sunny California
Dec 4, 2004
#18
  • Dec 4, 2004
  • #18
WORTH said:
first make sure you have a good ground. Clean a place on teh sender and a place on the frame and run a jumper wire. See if that fixes it, if not the sender may be out of adjustment,

if you check the ground and still have the problem, tell me where the guage reads when it is full, and where it reads when it is empty , and I will tell you how to adjust it.
Click to expand...

how do i put in the jumper wire?
 

WORTH

20+ Year Stangneter
Nov 18, 2002
2,166
44
98
Cape Cod, Ma.
Dec 4, 2004
#19
  • Dec 4, 2004
  • #19
SLEEPERstang21 said:
how do i put in the jumper wire?
Click to expand...

To test it just put a sheet metal screw threw the body somewhere and attach a wire to it, then clean the sender to metal and touch the wire to it.
 
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