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gas gauge problems
#21
(02-09-2019, 12:01 PM)rjpohl Wrote:
(02-09-2019, 11:37 AM)Stanglover Wrote:
(02-08-2019, 10:14 PM)rjpohl Wrote: With Randy’s help I was able to get gas gauge working.  Problem is with 5 gallons in tank the gauge just barely moves above empty.  In the morning I will remove sending unit and bend arm down.  Any one have this problem before?  If so suggestions on how much to bend.  I’d like to be able to do this in one try.

 You didn't read the last post on P1. I can further explain if not clear.

I did read the post and jacked car up that way to remove sending unit for bench testing it.  I was asking for suggestions on how much to bend the arm to bring it from just above E to 1/4 tank.  I'd like to get it right the first time and not have to jack car up and down several time.  Right now with 5 gallons in tank the needle is just a hair above E.  Unless someone has a suggestion I'll bend it about 1" down and reinstall/check and go from there.
Thanks
Bob
 It is a PITA for sure, but I think 1" would be too much. I don't recall exactly how much I bent mine, maybe only a 1/4" to go from 1/8th to 1/4. Sorry, but it's a trial and error thing, BUT you might get lucky. Once you get to the 1/4, go fill up and check the top end. My gauge is a bit off at the top. Sometimes it reads just below the full mark, sometimes it goes above. I usually fill till the pump clicks off, then go to nearest dollar, so It's pretty consistent.
Good luck,
Geoff.

I learn something new every day!
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#22
Got the car jacked up and removed the new sending unit. I reconnected the plug and ran a ground to the body of the sending unit. Propped the float in the full position and then turned the key on. The gauge needle starts to move and goes all the way to full, stays there a split second or so and then goes slowly back to E. I then ran same set up with the old sending unit and it did exactly the same thing.
I also propped the used sending unit in about the middle and the needle ran up to a hair above 1/4 tank and then returned to E.
Any ideas?
thanks
Bob
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#23
Manually testing the float requires that you ensure that the movable arm touches the variable resistor so it sends a consistent signal. There's some slop in the arm, so that it wiggles sideways, at least in the earlier model years. Other than that, it shouldn't peg and then drop, unless your ground lead came off...

Let me check your shorts!
http://midlifeharness.com

[Image: Flamicon2.jpg]


[Image: oldfart.png]
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#24
(02-12-2019, 10:14 AM)midlife Wrote: Manually testing the float requires that you ensure that the movable arm touches the variable resistor so it sends a consistent signal.  There's some slop in the arm, so that it wiggles sideways, at least in the earlier model years.  Other than that, it shouldn't peg and then drop, unless your ground lead came off...

I bent the float arm down quite a bit, reinstalled and turned on the ignition, the needle went above 1/2 tank and then gradually went down to E again.  I have a ground wire ran from the battery to the sending unit.
thanks
Bob
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#25
Here's another thing that may help with figuring it out.

I turn key ON and the gauge moves toward full then at some point returns to below E.  If I turn key OFF and right back ON the needle does not move up but if I wait 15 seconds or so before turning back ON it does move up.

Thanks for the help guys.
Bob
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#26
Did you change out your CVR like you said you would? That's about the only thing that is current- or heat-related, other than the resistor wire crimp that can undo with heat...

Let me check your shorts!
http://midlifeharness.com

[Image: Flamicon2.jpg]


[Image: oldfart.png]
  Reply
#27
(02-12-2019, 12:51 PM)midlife Wrote: Did you change out your CVR like you said you would?  That's about the only thing that is current- or heat-related, other than the resistor wire crimp that can undo with heat...

Have not changed out the CVR.  I guess I could buy one and give it a try.
I took voltage reading at the CVR (resistor wire connection to gound) and I get a steady 12vdc +.

Bob
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#28
I took voltage reading from the output side of the CVR.  Turn key ON voltage goes to 10.5 vdc and then drops to 0.01 quickly.  Shouldn't the voltage be a steady reading of at least a few volts for 1/4 tank?  I'm leaning toward bad CVR.
thanks
Bob
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#29
The output of the CVR should change from 12V to 0V and back again. The fact that it went to zero and stayed there is a good indication that it is bad. It consists of a bi-metallic strip that heats up when voltage is applied and bends away from the contact. When it cools, it should rebound back to the 12V contact and start again.

Let me check your shorts!
http://midlifeharness.com

[Image: Flamicon2.jpg]


[Image: oldfart.png]
  Reply
#30
(02-12-2019, 08:45 PM)midlife Wrote: The output of the CVR should change from 12V to 0V and back again.  The fact that it went to zero and stayed there is a good indication that it is bad.  It consists of a bi-metallic strip that heats up when voltage is applied and bends away from the contact.  When it cools, it should rebound back to the 12V contact and start again.


I ordered one earlier today, thanks
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