Gas Gauge question (again) - The 1947 - Present Chevrolet & GMC Truck Message Board Network

jorgensensc · 11-10-2003, 10:47 PM

I tried a search, but couldn't find what I was looking for. My gas gauge worked fine after the blazer tank install (well, 3/4 tank= full, and under empty means empty). Well, I took the gauges out to paint the backs white for brightness reasons, put it all back together installed it, and now I get under empty for 1/2 tank, and almost no movement when full (I went and filled her up to make sure I wasn't crazy and out of gas). I unplugged the sending wire @ the fuse block and te auge went to full. What does it all mean?? Is the gauge supposed to go to full when open?? Is the resistor on the back supposed to go a certain direction? besides left to right? Once again, any help is greatly appreciated!!!Tanks,
Shawn

jorgensensc · 11-11-2003, 12:18 AM

Please guys, a little help. Don't make me beg!!!!!!TTT

Longhorn Man · 11-11-2003, 12:50 AM

I would try turning that resister around, but it sounds to me like your sender is heading south, ot the float don't float as well as it should.

jorgensensc · 11-11-2003, 12:53 AM

Thanks for the reply!!!! The sending unit is brand new. Could it be the gauge? Can you really put the resistor on backwards???

SS55 · 11-11-2003, 02:24 AM

The resistor direction is not the problem! Capacitors and Diodes are polarity sensitive, but not resistors. Is it possible that you tweaked the fuel gauge a little when you had it disassembled for painting?

jorgensensc · 11-11-2003, 02:33 AM

I've disassembled this thing a hundred times, this is the first time I've had this problem. Maybe I did tweak it somehow...

SS55 · 11-11-2003, 02:46 AM

I have seen a bad ground connection cause erratic readings but the symptoms are usually a fluctuating needle rather than what you are seeing, steady but wrong.

I think I have a couple of old dash assemblies out in the garage and if I have a working fuel gauge in the bunch, I can send it to you so you an verify if it is your gauge, wiring or grounding.

Let me know if you want to test one of mine and then loan it to you.

jorgensensc · 11-11-2003, 02:49 AM

That would be great if you could test one. I might be able to drive down (I'm on Camp Pendleton) and borrow it for the day to test it out. Thanks for the offer!!!!!

SS55 · 11-11-2003, 03:01 AM

I'll test one tomorrow afternoon and let you know if I'v got a working unit.

jorgensensc · 11-11-2003, 03:04 AM

Thanks!!!!

tom hand · 11-11-2003, 11:38 AM

I have read on this board of a couple of people getting brand new sending units for the blazer tanks that had bad floats. A pinhole in the float could be your problem.....the float is slowly sinking

BobbyK · 11-11-2003, 11:59 AM

So it worked before you took it out and once it was but back together it didn't work?

What you describe sounds like the gauge is grounded somewhere.

Make sure the leads are isolated and not touching or touching anything else.

Also check the printed circuit board where you plug the harness into it.Check those tabs and make sure they are not bent or crossed up somehow.

Other than moving the needle by hand you can't really "tweek" those things.It's a sealed gauge.
I know I have moved plenty of gas gauge needles by hand with no ill effects.

SS55 · 11-11-2003, 11:15 PM

jorgensensc

I sent you a PM

tommie · 11-11-2003, 11:23 PM

jorgensensc,

did you ever get pics of the filler neck install?

know that its off topic of your problem now, but just wondering.

tommie

jorgensensc · 11-12-2003, 01:51 AM

Tommie,
Here are a couple if pics. They are not all I have and I didn't get to get more taken today. I will get to it I promise. I will post the install very soon!!!

jorgensensc · 11-12-2003, 01:53 AM

2

jorgensensc · 11-12-2003, 01:54 AM

3

jorgensensc · 11-12-2003, 01:56 AM

4
As I said before, I need to get pics of the final product, Then I can give you dimensions and a parts list!!!

dinnut · 11-12-2003, 01:56 AM

very nice work. i wanna do that when i goto blazer install. sure the parts from truck shop arent crazy? maybe the kit is cheap for a reason. im not trying to talk bad. im gonna buy a pantload full of stuff from them real soon. im just wondering

jorgensensc · 11-12-2003, 02:43 AM

Dinnut,
The tank works great, maybe tey are crazy, or don't realize what they got going for them.

tommie · 11-12-2003, 12:59 PM

jorgensensc,

thanks for the pics, wasn't tring to bug you about it, just making sure i didn't miss it when i was at work, and can't get on the net...

jorgensensc · 11-13-2003, 03:08 AM

I got the gauge today!!!! Thanks!!! Steve is a really nice guy and I appreciate your help!!!! I have a question though. I installed the gauge this evening and it seemed to work!! I filled up the tank to make sure and it went to 1 notch below full. Is this what it was registering with you? I drove alot and it seemed to go down evenly with the fuel level. Do you think it is my sending unit? It is new. Is there a way to calibrate the sending unit? Also does the length of the wire to the sending unit affect the signal? I know that length can affect voltage, but ohmage? I put a blazer tank in and it is about 5 ft' further than the original wire to the old tank. What do you think?? Thank you again, your a Great Member!!!!!

11-10-2003, 10:47 PM	#1
jorgensensc Registered User Join Date: Jul 2003 Location: Cypress, Tx Posts: 4,005	Gas Gauge question (again) I tried a search, but couldn't find what I was looking for. My gas gauge worked fine after the blazer tank install (well, 3/4 tank= full, and under empty means empty). Well, I took the gauges out to paint the backs white for brightness reasons, put it all back together installed it, and now I get under empty for 1/2 tank, and almost no movement when full (I went and filled her up to make sure I wasn't crazy and out of gas). I unplugged the sending wire @ the fuse block and te auge went to full. What does it all mean?? Is the gauge supposed to go to full when open?? Is the resistor on the back supposed to go a certain direction? besides left to right? Once again, any help is greatly appreciated!!!Tanks, Shawn __________________ 1972 C20 Suburban- Big Blue Betty '56 Chevy Bel Air Sedan- Frame up Restoration -What would you attempt to achieve if you knew you could not fail?- -I Refuse To Tiptoe Through Life, Only To Arrive Safely At Death's Door- R.I.P. EAST SIDE LOW LIFE

11-11-2003, 12:18 AM	#2
jorgensensc Registered User Join Date: Jul 2003 Location: Cypress, Tx Posts: 4,005	Please guys, a little help. Don't make me beg!!!!!!TTT __________________ 1972 C20 Suburban- Big Blue Betty '56 Chevy Bel Air Sedan- Frame up Restoration -What would you attempt to achieve if you knew you could not fail?- -I Refuse To Tiptoe Through Life, Only To Arrive Safely At Death's Door- R.I.P. EAST SIDE LOW LIFE

11-11-2003, 12:53 AM	#4
jorgensensc Registered User Join Date: Jul 2003 Location: Cypress, Tx Posts: 4,005	Thanks for the reply!!!! The sending unit is brand new. Could it be the gauge? Can you really put the resistor on backwards??? __________________ 1972 C20 Suburban- Big Blue Betty '56 Chevy Bel Air Sedan- Frame up Restoration -What would you attempt to achieve if you knew you could not fail?- -I Refuse To Tiptoe Through Life, Only To Arrive Safely At Death's Door- R.I.P. EAST SIDE LOW LIFE

11-11-2003, 02:24 AM	#5
SS55 Registered User Join Date: Nov 2003 Location: San Diego, CA Posts: 62	The resistor direction is not the problem! Capacitors and Diodes are polarity sensitive, but not resistors. Is it possible that you tweaked the fuel gauge a little when you had it disassembled for painting? __________________ Be wary of the light at the end of the tunnel....It might be a gorilla holding a flashlight! 71 Blazer, ex-4WD...Bought it that way 55 GMC 55 Belair 2dr HT 67 El Camino

11-11-2003, 02:33 AM	#6
jorgensensc Registered User Join Date: Jul 2003 Location: Cypress, Tx Posts: 4,005	I've disassembled this thing a hundred times, this is the first time I've had this problem. Maybe I did tweak it somehow... __________________ 1972 C20 Suburban- Big Blue Betty '56 Chevy Bel Air Sedan- Frame up Restoration -What would you attempt to achieve if you knew you could not fail?- -I Refuse To Tiptoe Through Life, Only To Arrive Safely At Death's Door- R.I.P. EAST SIDE LOW LIFE

11-11-2003, 12:50 AM	#3
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	I would try turning that resister around, but it sounds to me like your sender is heading south, ot the float don't float as well as it should.

11-11-2003, 02:46 AM	#7
SS55 Registered User Join Date: Nov 2003 Location: San Diego, CA Posts: 62	I have seen a bad ground connection cause erratic readings but the symptoms are usually a fluctuating needle rather than what you are seeing, steady but wrong. I think I have a couple of old dash assemblies out in the garage and if I have a working fuel gauge in the bunch, I can send it to you so you an verify if it is your gauge, wiring or grounding. Let me know if you want to test one of mine and then loan it to you. __________________ Be wary of the light at the end of the tunnel....It might be a gorilla holding a flashlight! 71 Blazer, ex-4WD...Bought it that way 55 GMC 55 Belair 2dr HT 67 El Camino

11-11-2003, 02:49 AM	#8
jorgensensc Registered User Join Date: Jul 2003 Location: Cypress, Tx Posts: 4,005	That would be great if you could test one. I might be able to drive down (I'm on Camp Pendleton) and borrow it for the day to test it out. Thanks for the offer!!!!! __________________ 1972 C20 Suburban- Big Blue Betty '56 Chevy Bel Air Sedan- Frame up Restoration -What would you attempt to achieve if you knew you could not fail?- -I Refuse To Tiptoe Through Life, Only To Arrive Safely At Death's Door- R.I.P. EAST SIDE LOW LIFE

11-11-2003, 03:01 AM	#9
SS55 Registered User Join Date: Nov 2003 Location: San Diego, CA Posts: 62	I'll test one tomorrow afternoon and let you know if I'v got a working unit. __________________ Be wary of the light at the end of the tunnel....It might be a gorilla holding a flashlight! 71 Blazer, ex-4WD...Bought it that way 55 GMC 55 Belair 2dr HT 67 El Camino

11-11-2003, 03:04 AM	#10
jorgensensc Registered User Join Date: Jul 2003 Location: Cypress, Tx Posts: 4,005	Thanks!!!! __________________ 1972 C20 Suburban- Big Blue Betty '56 Chevy Bel Air Sedan- Frame up Restoration -What would you attempt to achieve if you knew you could not fail?- -I Refuse To Tiptoe Through Life, Only To Arrive Safely At Death's Door- R.I.P. EAST SIDE LOW LIFE

11-11-2003, 11:38 AM	#11
tom hand CCRider Join Date: Feb 2000 Location: Olive Branch,MS,USA Posts: 2,232	I have read on this board of a couple of people getting brand new sending units for the blazer tanks that had bad floats. A pinhole in the float could be your problem.....the float is slowly sinking __________________ 72 GMC Sierra SWB almost finished---- 84 Softail Olive Branch MS

11-11-2003, 11:59 AM	#12
BobbyK Registered User Join Date: May 2000 Location: Petrolia,Ontario,Canada but working in Port Huron,Mi. Posts: 1,772	So it worked before you took it out and once it was but back together it didn't work? What you describe sounds like the gauge is grounded somewhere. Make sure the leads are isolated and not touching or touching anything else. Also check the printed circuit board where you plug the harness into it.Check those tabs and make sure they are not bent or crossed up somehow. Other than moving the needle by hand you can't really "tweek" those things.It's a sealed gauge. I know I have moved plenty of gas gauge needles by hand with no ill effects. __________________ 71 blazer,350SBC,approx.375HP,700R4,factory GM TPI.Dual electric fans,33x12.5x15 ATR on stock suspension. Petrolia,Ontario,Canada but working in Port Huron,MI. See ALL my Blazer pic's HERE

11-11-2003, 11:15 PM	#13
SS55 Registered User Join Date: Nov 2003 Location: San Diego, CA Posts: 62	jorgensensc I sent you a PM __________________ Be wary of the light at the end of the tunnel....It might be a gorilla holding a flashlight! 71 Blazer, ex-4WD...Bought it that way 55 GMC 55 Belair 2dr HT 67 El Camino

11-11-2003, 11:23 PM	#14
tommie 97' Tahoe 2dr/2wd Join Date: Jul 2002 Location: Huffman,TX Posts: 1,168	jorgensensc, did you ever get pics of the filler neck install? know that its off topic of your problem now, but just wondering. tommie

11-12-2003, 01:51 AM	#15
jorgensensc Registered User Join Date: Jul 2003 Location: Cypress, Tx Posts: 4,005	Tommie, Here are a couple if pics. They are not all I have and I didn't get to get more taken today. I will get to it I promise. I will post the install very soon!!! Attached Images __________________ 1972 C20 Suburban- Big Blue Betty '56 Chevy Bel Air Sedan- Frame up Restoration -What would you attempt to achieve if you knew you could not fail?- -I Refuse To Tiptoe Through Life, Only To Arrive Safely At Death's Door- R.I.P. EAST SIDE LOW LIFE



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11-12-2003, 01:53 AM	#16
jorgensensc Registered User Join Date: Jul 2003 Location: Cypress, Tx Posts: 4,005	2 Attached Images __________________ 1972 C20 Suburban- Big Blue Betty '56 Chevy Bel Air Sedan- Frame up Restoration -What would you attempt to achieve if you knew you could not fail?- -I Refuse To Tiptoe Through Life, Only To Arrive Safely At Death's Door- R.I.P. EAST SIDE LOW LIFE

11-12-2003, 01:54 AM	#17
jorgensensc Registered User Join Date: Jul 2003 Location: Cypress, Tx Posts: 4,005	3 Attached Images __________________ 1972 C20 Suburban- Big Blue Betty '56 Chevy Bel Air Sedan- Frame up Restoration -What would you attempt to achieve if you knew you could not fail?- -I Refuse To Tiptoe Through Life, Only To Arrive Safely At Death's Door- R.I.P. EAST SIDE LOW LIFE

11-12-2003, 01:56 AM	#18
jorgensensc Registered User Join Date: Jul 2003 Location: Cypress, Tx Posts: 4,005	4 As I said before, I need to get pics of the final product, Then I can give you dimensions and a parts list!!! Attached Images __________________ 1972 C20 Suburban- Big Blue Betty '56 Chevy Bel Air Sedan- Frame up Restoration -What would you attempt to achieve if you knew you could not fail?- -I Refuse To Tiptoe Through Life, Only To Arrive Safely At Death's Door- R.I.P. EAST SIDE LOW LIFE

11-12-2003, 01:56 AM	#19
dinnut Registered User Join Date: Apr 2003 Location: missouri city, tx Posts: 4,486	very nice work. i wanna do that when i goto blazer install. sure the parts from truck shop arent crazy? maybe the kit is cheap for a reason. im not trying to talk bad. im gonna buy a pantload full of stuff from them real soon. im just wondering __________________ 70 longbed 496/th400/Ford 9"

11-12-2003, 02:43 AM	#20
jorgensensc Registered User Join Date: Jul 2003 Location: Cypress, Tx Posts: 4,005	Dinnut, The tank works great, maybe tey are crazy, or don't realize what they got going for them. __________________ 1972 C20 Suburban- Big Blue Betty '56 Chevy Bel Air Sedan- Frame up Restoration -What would you attempt to achieve if you knew you could not fail?- -I Refuse To Tiptoe Through Life, Only To Arrive Safely At Death's Door- R.I.P. EAST SIDE LOW LIFE

11-12-2003, 12:59 PM	#21
tommie 97' Tahoe 2dr/2wd Join Date: Jul 2002 Location: Huffman,TX Posts: 1,168	jorgensensc, thanks for the pics, wasn't tring to bug you about it, just making sure i didn't miss it when i was at work, and can't get on the net...

11-13-2003, 03:08 AM	#22
jorgensensc Registered User Join Date: Jul 2003 Location: Cypress, Tx Posts: 4,005	I got the gauge today!!!! Thanks!!! Steve is a really nice guy and I appreciate your help!!!! I have a question though. I installed the gauge this evening and it seemed to work!! I filled up the tank to make sure and it went to 1 notch below full. Is this what it was registering with you? I drove alot and it seemed to go down evenly with the fuel level. Do you think it is my sending unit? It is new. Is there a way to calibrate the sending unit? Also does the length of the wire to the sending unit affect the signal? I know that length can affect voltage, but ohmage? I put a blazer tank in and it is about 5 ft' further than the original wire to the old tank. What do you think?? Thank you again, your a Great Member!!!!! __________________ 1972 C20 Suburban- Big Blue Betty '56 Chevy Bel Air Sedan- Frame up Restoration -What would you attempt to achieve if you knew you could not fail?- -I Refuse To Tiptoe Through Life, Only To Arrive Safely At Death's Door- R.I.P. EAST SIDE LOW LIFE

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