1967 gas gauge issue

[67HEAVEN]

Yes,

Thanks for all the information. I've been so busy with the business since Carlisle, I haven't even scrubbed the bug guts off yet.

Tomorrow's the day for the suggested tests.

Thanks again. I'll report back.

 

[paul67]

Stepinwolf,
Try GM Canada inventory, particularly Woodstock, Ontario. I may be wrong but....

 

[67HEAVEN]

Test results are in:

Actual situation: Gauge shows 1/8.....tank is 1/2 full

With ignition switch on:
removed pink wire - gauge goes from 1/8 to 1/2
reconnect pink - gauge returns to 1/8

removed tan wire - gauge goes from 1/8 to 1/2 (same as above)
reconnect tan - gauge returns to 1/8 (as above)

remove tan wire and jump to ground - gauge goes to FULL

Reading between tan wire and sending unit terminal:
ignition switch off - 140 ohms
ignition turned on - off the scale (beyond 1K ohms)

:confused
There seems to be conflicting evidence here.

 

[Geek's 65]

Some of this is actually better than you think. "Remove the tan wire and jump to ground guage goes to full". If you are grounding the tan wire then that's exactly what the guage should do. Zero ohms to ground on the tan wire is a full tank of gas. You could get a 100 ohm potentiometer at Radio Shack and hook the wiper of it to the tan wire and one end of the coil to ground. As you vary the resistance of the pot you can watch the gas guage go from zero to full. That would take the guage itself out of the hunt. Also---

There is no way reading from the tan wire to the send unit (where the pink wire hooks up?) can read 140 ohms. 90 ohms max and that's only with a full tank. If you have half a tank then the reading should be about 45 ohms. Think the reason you are going off the scale on the tan wire with the ignition on is that there is voltage present. It's coming though the winding of the fuel guage but it's there just the same and your meter doesn't like that. Also when you turn the ignition on, you should read a full 12VDC on the pink wire. If you have that then the problem is certainly the sender.

Geek

 

[JohnZ]

With the tan wire grounded and the key on, the gauge should show empty (zero resistance), not full.....

 

[67HEAVEN]

Diagnosis, gentlemen?

Gauge? Sending unit? Phase of the moon? High tide?

 

[Viet Nam Vett]

Diagnosis, gentlemen?

Gauge? Sending unit? Phase of the moon? High tide?

Phase of the moon? High tide?
:L Condition Of The Ozone Layer......:L

 

[youwish2bme]

Bob, If you remove the two wires from the sender and read across the terminals you should have as posted 0 at empty and 90 at full (or vise versa).. No need to have the key on or off or go to ground. Just read across the terminals. As you have you meter on the terminals have someone move the float arm. It should go from 0-90 and back as it is moved up and down. If it does then your problem is the gauge or the wiring. If it the resistance reading does not change evenly than it could be the sender. If it smoothly goes up and down with the float lever it is a great chance that it could be the gauge... Dave..

Here is a pic of when I had my sender out a few months ago...

empty then full...

 

[67HEAVEN]

Great info, Dave. I made up a loop out of very heavy gauge wire to grab the float with so that I can move it up and down.

I'll try it on the weekend.

Thanks.

 

[stepinwolf]

Great info, Dave. I made up a loop out of very heavy gauge wire to grab the float with so that I can move it up and down.

I'll try it on the weekend.

Thanks.

Bob, I would not be comfortable using metal wires :nono or other metal objects in the presence of the gas fumes that will be emanating from your gas tank. You undoubtedly can find something other then metal to do your tests.

My guess is that the problem will eventually be traced to the sender, but nowhere in this post was the gauge itself addressed. As for myself, with the time involved in removing a cluster for service, I never install one without having ALL the various gauges restored, repaired, and or calibrated, before their installation.

Not wanting to fault any decisions that were made during the restoration, did you have the fuel gauge serviced before it's installation, or take it for granted that since it worked before, it should be OK. ?

Not wanting to criticize, just trying to help in narrowing the search.

Stepinwolf

 

[67HEAVEN]

Bob, I would not be comfortable using metal wires :nono or other metal objects in the presence of the gas fumes that will be emanating from your gas tank. You undoubtedly can find something other then metal to do your tests.

My guess is that the problem will eventually be traced to the sender, but nowhere in this post was the gauge itself addressed. As for myself, with the time involved in removing a cluster for service, I never install one without having ALL the various gauges restored, repaired, and or calibrated, before their installation.

Not wanting to fault any decisions that were made during the restoration, did you have the fuel gauge serviced before it's installation, or take it for granted that since it worked before, it should be OK. ?

Not wanting to criticize, just trying to help in narrowing the search.

Stepinwolf

Bob,

The wire has a rubberized coating.

All gauges are new, except for the speedo.

 

[stepinwolf]

Bob,

The wire has a rubberized coating.

All gauges are new, except for the speedo.

67Heaven

Just checking, wouldn't want anything to happen to you.

Stepinwolf

 

[67HEAVEN]

Bob, If you remove the two wires from the sender and read across the terminals you should have as posted 0 at empty and 90 at full (or vise versa).. No need to have the key on or off or go to ground. Just read across the terminals. As you have you meter on the terminals have someone move the float arm. It should go from 0-90 and back as it is moved up and down. If it does then your problem is the gauge or the wiring. If it the resistance reading does not change evenly than it could be the sender. If it smoothly goes up and down with the float lever it is a great chance that it could be the gauge... Dave..

Thanks, Dave.

It's starting to look like a bad gauge. Your suggestion results in an even and gradual progressive reading from empty to full and back. Due to the angle involved, through the tank mouth, I am only able to push the float down to "almost" empty and pull up to "almost" full. The readings go from 20 ohms to 80 ohms.

By the way, all wiring harnesses in the car are new from Lectric Limited.

During the drive to the cottage, I filled up and paid special attention to the gauge. Observation.......wildly swinging readings from full to 1/4 to 3/4 to 1/2 to full again......several times.......before settling at 1/8 (with a full tank :eyerole ).

Any more feedback before I contact ZIP about the gauge?

 

[stepinwolf]

Thanks, Dave.

It's starting to look like a bad gauge. Your suggestion results in an even and gradual progressive reading from empty to full and back. Due to the angle involved, through the tank mouth, I am only able to push the float down to "almost" empty and pull up to "almost" full. The readings go from 20 ohms to 80 ohms.

By the way, all wiring harnesses in the car are new from Lectric Limited.

During the drive to the cottage, I filled up and paid special attention to the gauge. Observation.......wildly swinging readings from full to 1/4 to 3/4 to 1/2 to full again......several times.......before settling at 1/8 (with a full tank :eyerole ).

Any more feedback before I contact ZIP about the gauge?

Yes Bob,

The only feedback I can give you is " good luck with zip ". They once reneged on a 5$ bill, and after dozens of back & forth e-mails, I put it in the " BAD EXPERIENCE " folder.

As far as affordable replacement gauges, I met a gentlemen at last years show ( Carlisle ) who has the complete line of Delco small gauges. He spent most of the weekend going around the various vendors, giving out free correct temperature sensors to introduce himself, and offered a complete line of Delco gauges at more then competitive pricing. I don't have any web info, but I jotted down his vitals, and this is what they are

Ken Anderson
K & B Special Products
5175 Overbend Trail
Suwanee, GA.
30024
Phone & Fax 770-932-0867

I have not had the occasion to call, so I can't vouch for the above information

Stepinwolf

 

[67HEAVEN]

As far as affordable replacement gauges, I met a gentlemen at last years show ( Carlisle ) who has the complete line of Delco small gauges. He spent most of the weekend going around the various vendors, giving out free correct temperature sensors to introduce himself, and offered a complete line of Delco gauges at more then competitive pricing. I don't have any web info, but I jotted down his vitals, and this is what they are

Ken Anderson
K & B Special Products
5175 Overbend Trail
Suwanee, GA.
30024
Phone & Fax 770-932-0867

I have not had the occasion to call, so I can't vouch for the above information

Stepinwolf

Bob,

You have no idea what a coincidence this is.

More later.

 

[youwish2bme]

Bob, Well at least you now know the sender is working properly and that it is most likely the gauge. I'd just call Zip and tell em you need a new gauge. They have accepted returns from me over the last two years and I've spent a bunch there as you have I'm sure. They've never given me a problem at all... I just got a new fuel pump from them last month because of a problem with the one I got from them less than a year ago.. No questions asked.. Just it'll be shipped today or tomorrow.. I got it the next day. Same thing with other parts that have failed. They offer a one year warranty on most parts...

Glad I could help out on the sender issue... Dave...

 

[Geek's 65]

I'm not so sure it's your gauge Bob. The resistance you measured between the tan and the pink wire is right on but that's actually only half the test. This thing is actually a voltage divider type circuit and not just a resistance circuit (I think John Z has said before it's one of the only times the General did it this way) . It's not just the resistance between those two lines. It's also the resistance between the tan line and the ground (which sets where the guage is going to read) as well as the pink line to ground. Earlier you had measured 140 ohms before on the tan line before and there is no way to get that without something being amiss down there. As much as I hate to fall back to the old Corvette electrical excuse, if your sender doesn't have a good ground (reference), it will jump that guage all around just like you are seeing. Might want to try reading the resistance again while moving the float but read from the tan wire to a ground on the car (not the one on the sender) to see if you are getting that same smooth 2 to 90 ohm change. You can read the pink wire to ground and see if you get 90 ohms (doesn't change when you move the float). If you do, then I am all wet. If you don't, then you might be victim of the almighty, alscrewing ground god.

Geek

 

[youwish2bme]

I must of missed John's post on senders. I thought that it was just a resistance network with the float arm acting as the wiper on the resistor to adjust current flow to change the deflection of the guage needle... FWIW... I just went out and I have less than a half of a tank.. 37 ohms across the terminals then I measured each to gnd... 70 on the pink and 100 on the tan.... Across the pink and tan wires it's about 120 ohms but that is reading across the guage.... Don't know if that helps or not..... Dave....

 

[Geek's 65]

Dave

 

[Geek's 65]

Dave was the sender still connected to the car when you got those readings? With only 70 on the pink and 100 on the tan it sounds like you are reading back through the car. Apologize but all my numbers were with the tan and pink wire disconnected from the sender.

Geek