FUEL GUAGE PROBLEM

[RedFish]

I used a decade resistance bank which allowed me the test and calibrate much more than the service techs 3 position tester. That doesn't mean I could force or alter the aftermarkets linear sender to function like the OEM non-linear sender. What I did know.., all the gauges operate on the same 80-10 range. 78 ohms would begin to slightly warm the gauge winding but not enough to cause needle movement. 73 ohms would or should bring the needle to the lowest hash mark (on a fuel gauge that up to the E). Approx' 34 ohms is both 1/4 tank of fuel gauge and 180 degrees where thermostat would begin to open also. I don't recall how much oil pressure 34 ohms represents. I could go drag out my books but you may not have a oil gauge in a standard panel anyway.
I did read 3 ohms in one of the posts above which disturbs me. As low as 8 ohms can overheat the bimetal beam inside the gauge given enough time. Once that beam loses its original form (arrow straight at 68 degrees) it will remain bowed so the needle can't go all the way to its home position at switch off. If off there its off throughout its range/movement.

 

[sgrip65]

I used a decade resistance bank which allowed me the test and calibrate much more than the service techs 3 position tester. That doesn't mean I could force or alter the aftermarkets linear sender to function like the OEM non-linear sender. What I did know.., all the gauges operate on the same 80-10 range. 78 ohms would begin to slightly warm the gauge winding but not enough to cause needle movement. 73 ohms would or should bring the needle to the lowest hash mark (on a fuel gauge that up to the E). Approx' 34 ohms is both 1/4 tank of fuel gauge and 180 degrees where thermostat would begin to open also. I don't recall how much oil pressure 34 ohms represents. I could go drag out my books but you may not have a oil gauge in a standard panel anyway.
I did read 3 ohms in one of the posts above which disturbs me. As low as 8 ohms can overheat the bimetal beam inside the gauge given enough time. Once that beam loses its original form (arrow straight at 68 degrees) it will remain bowed so the needle can't go all the way to its home position at switch off. If off there its off throughout its range/movement.

RedFish. Thank You. This is great info. sgrip65

 

[Ken71Twister]

I used a decade resistance bank which allowed me the test and calibrate much more than the service techs 3 position tester. That doesn't mean I could force or alter the aftermarkets linear sender to function like the OEM non-linear sender. What I did know.., all the gauges operate on the same 80-10 range. 78 ohms would begin to slightly warm the gauge winding but not enough to cause needle movement. 73 ohms would or should bring the needle to the lowest hash mark (on a fuel gauge that up to the E). Approx' 34 ohms is both 1/4 tank of fuel gauge and 180 degrees where thermostat would begin to open also. I don't recall how much oil pressure 34 ohms represents. I could go drag out my books but you may not have a oil gauge in a standard panel anyway.
I did read 3 ohms in one of the posts above which disturbs me. As low as 8 ohms can overheat the bimetal beam inside the gauge given enough time. Once that beam loses its original form (arrow straight at 68 degrees) it will remain bowed so the needle can't go all the way to its home position at switch off. If off there its off throughout its range/movement.

RedFish…. I’m the one with the gauge that needs to go down to 3 ohms to get it to Full. FYI - I’m also using a decade resistance bank. If I read you correctly - My gauge is going to be toast if I come up with a device to “make” it read correctly. I suppose my money and effort might be best spent buying a new gauge while I have the instrument panel out. As is… the gauge barely comes up to the “E” with the sending unit resistance at 42 ohms.

 

[Ken71Twister]

Before I order a new fuel gauge - anyone have a suggestion vs what I might do to get my existing gauge to work? If I buy a new gauge - any recommendations for who to buy from?

 

[RedFish]

RedFish…. I’m the one with the gauge that needs to go down to 3 ohms to get it to Full. FYI - I’m also using a decade resistance bank. If I read you correctly - My gauge is going to be toast if I come up with a device to “make” it read correctly. I suppose my money and effort might be best spent buying a new gauge while I have the instrument panel out. As is… the gauge barely comes up to the “E” with the sending unit resistance at 42 ohms.

I can't see all/know all from here. I can only tell you what I know and what I have seen... The nichrome wire that is wound on the bi-metal inside the thermal guage has a spiral wound fiberglass insulation that is so fine it can hardly be seen. It should be a pale yellowish color. This insoluates the wire from the beam but allows it to move also, so the beam can bow and move the needle. I have opened gauges to see the insulation appear 5 times it original diameter due to the carbon build up on it. I would contribute most of this to smoking in the vehicle and the ashtray just below to fuel gauge in some models. That buildup of nastiness would restrict beam movement like an elastic bandage wrapped on your arm.
Many times I would see what looked like ground black pepper at the bottom of the gauge and a smoke strain at the top of the gauge and immediately know what I was going to find when I opened the gauge.

 

[Ken71Twister]

I can't see all/know all from here. I can only tell you what I know and what I have seen... The nichrome wire that is wound on the bi-metal inside the thermal guage has a spiral wound fiberglass insulation that is so fine it can hardly be seen. It should be a pale yellowish color. This insoluates the wire from the beam but allows it to move also, so the beam can bow and move the needle. I have opened gauges to see the insulation appear 5 times it original diameter due to the carbon build up on it. I would contribute most of this to smoking in the vehicle and the ashtray just below to fuel gauge in some models. That buildup of nastiness would restrict beam movement like an elastic bandage wrapped on your arm.
Many times I would see what looked like ground black pepper at the bottom of the gauge and a smoke strain at the top of the gauge and immediately know what I was going to find when I opened the gauge.

I had an interesting find yesterday. I decided to test my fuel and temp gauges using a device that allowed me to “dial in” a desired DC voltage. I adjusted it to provide close to 5 V at the gauges and tested each with the variable resister that I have. They both worked perfectly. I re-checked the voltage limiter and it is still giving the pulsing voltage - suggesting that its working somewhat as it should. My gut tells me that I should abandon the voltage limiter and come up with a device that will provide a steady 5 volts at the gauges. Does that make sense to you?

 

[Ken71Twister]

I had an interesting find yesterday. I decided to test my fuel and temp gauges using a device that allowed me to “dial in” a desired DC voltage. I adjusted it to provide close to 5 V at the gauges and tested each with the variable resister that I have. They both worked perfectly. I re-checked the voltage limiter and it is still giving the pulsing voltage - suggesting that its working somewhat as it should. My gut tells me that I should abandon the voltage limiter and come up with a device that will provide a steady 5 volts at the gauges. Does that make sense to you?

A quick search within the site here and I came up with a reference to a solid state voltage limiter by a company called Real Time Engineering. Specifically - they offer a device called an IVR4 for my car for $50. Have any good or bad experience with that source?

 

[RedFish]

A quick search within the site here and I came up with a reference to a solid state voltage limiter by a company called Real Time Engineering. Specifically - they offer a device called an IVR4 for my car for $50. Have any good or bad experience with that source?

I don't have any experience with products from RTE. Like you, I find them the most advertised all over the interweb including this forum. One of the reasons is ease of installation. It will plug into the back of a standard inst' panel just like OEM.
A product called "meter match" was very popular also but as time goes by other mfgrs offer pretty much the same products at a wide range of prices.
If I was seeking a solid-state gauge voltage regulator, I would just search that at ebay. Any will work if wired into the circuit properly. It doesn't absolutely have to be located on the back of the inst' panel. With a little longer wiring it could be placed anywhere under the dash.
If the IVR4 still has the flashing LEDs on it (which surely contributes to its cost), wouldn't they be more useful if located where they can be seen?

 

[Ken71Twister]

I don't have any experience with products from RTE. Like you, I find them the most advertised all over the interweb including this forum. One of the reasons is ease of installation. It will plug into the back of a standard inst' panel just like OEM.
A product called "meter match" was very popular also but as time goes by other mfgrs offer pretty much the same products at a wide range of prices.
If I was seeking a solid-state gauge voltage regulator, I would just search that at ebay. Any will work if wired into the circuit properly. It doesn't absolutely have to be located on the back of the inst' panel. With a little longer wiring it could be placed anywhere under the dash.
If the IVR4 still has the flashing LEDs on it (which surely contributes to its cost), wouldn't they be more useful if located where they can be seen?

I guess a flashing LED might be a bit hard to see on the back of the instrument cluster.

 

[Ken71Twister]

I’m not strong on electronics so I’d like to ask if the item shown in the picture would do the job for supplying the necessary 5V to my temp and fuel gauges.