- City
- Halifax
- State
- UK
And if you want air con just open a window dead easy...
Fuel Gauge/Temp Gauge Regulator Replacement Experiment
- Thread starter Dave The Sparky
- Start date
- City
- Halifax
- State
- UK
We have moved on since then (i hope) not sure about the Scousers though 
- City
- Halifax
- State
- UK
Well inspired by @cbford i have made a chart of gallons/amps etc to try and find out where my setup will be when the gauge reads empty.
The fuel sender readings are pure guess work as the sender isn't on a linear graph and i have spent far too much time already just doing this to be plotting stuffs on graphs as well! 😁.
So if my dodgy sums are correct going off the 40.5 ohms it took to read empty on my setup at 6.1 Volts then it would suggest i will have approx 3.5 gallon or thereabouts in the tank left when the gauge reads empty.
As mentioned in @cbfords post higher on the voltage will help the lower end but may not do the world of good to the gauge when tank is full.
6.5 Volts would show empty at 3 Gallon but would shove 0.21 Amps in to the gauge at Full and as discussed not sure where the line is drawn between a working gauge and a wisp of smoke and no gauge.
Time to leave it as is i think and see what happens but i seem to have said that several times in this thread before....
Sums were done using 20 ohms as a resistance within the gauge and although some (maybe all..) of this is guess work i cannot think for a minute that all Jeeps left the factory with an accurate temperature/fuel gauge or maybe they did and thats the place that AMC spent sll the R+D money on?.
The fuel sender readings are pure guess work as the sender isn't on a linear graph and i have spent far too much time already just doing this to be plotting stuffs on graphs as well! 😁.
So if my dodgy sums are correct going off the 40.5 ohms it took to read empty on my setup at 6.1 Volts then it would suggest i will have approx 3.5 gallon or thereabouts in the tank left when the gauge reads empty.
As mentioned in @cbfords post higher on the voltage will help the lower end but may not do the world of good to the gauge when tank is full.
6.5 Volts would show empty at 3 Gallon but would shove 0.21 Amps in to the gauge at Full and as discussed not sure where the line is drawn between a working gauge and a wisp of smoke and no gauge.
Time to leave it as is i think and see what happens but i seem to have said that several times in this thread before....
Sums were done using 20 ohms as a resistance within the gauge and although some (maybe all..) of this is guess work i cannot think for a minute that all Jeeps left the factory with an accurate temperature/fuel gauge or maybe they did and thats the place that AMC spent sll the R+D money on?.
- City
- Seattle
- State
- WA
I have a similar problem... temp started reading low and it seems the also throw the fuel gauge off. So is the conclusion that the voltage regulator is the "weak link", the primary failure component? The reason I ask is that the previous time I had a gauge fail it was the wrapped resistance wire that failed...
- City
- Seattle
- State
- WA
"these gauges have been engineered for better, longer performance over the factory version and rely on an internal resistor system."
Is that an actual upgrade, or are these the same cheapo's I already used to replace the oem's?
Is that an actual upgrade, or are these the same cheapo's I already used to replace the oem's?
- City
- Halifax
- State
- UK
Before i get back to work after the holiday i had a bit of time to solder all my components together for the voltage regulator mark 2 which have been sat on my workbench for quite a while now.
Its a lot more compact and far more adjustable as well.
Non isolated ground so the 12volt input and the 5 to 10 volt output share the ground so its only 3 wires and hopefully will not cause issues.
Its a lot more compact and far more adjustable as well.
Non isolated ground so the 12volt input and the 5 to 10 volt output share the ground so its only 3 wires and hopefully will not cause issues.
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- Halifax
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- UK
So set it at 6.3Volts or thereabouts for now and will install this afternoon and see if it works as it should.
Only trouble is the 8 is tucked up in the garage away from road salt so may take a while to get some real results.
Only trouble is the 8 is tucked up in the garage away from road salt so may take a while to get some real results.
- City
- Halifax
- State
- UK
Its cost me about $25 in parts and i do not expect it to read correctly at low fuel level or when the engine temperature is cold.
If my experiments are correct the tank should still have 3 to 4 gallon still in there at empty but i can live with that, far better than the other way around and running out.
If this works i will make anther one for the 8 thats slowly getting welded but either use a fixed resistor to set the voltage or a smaller potentiometer so i can fit it all in the box without drilling a hole for the adjuster.
If my experiments are correct the tank should still have 3 to 4 gallon still in there at empty but i can live with that, far better than the other way around and running out.
If this works i will make anther one for the 8 thats slowly getting welded but either use a fixed resistor to set the voltage or a smaller potentiometer so i can fit it all in the box without drilling a hole for the adjuster.
- City
- Halifax
- State
- UK
Installed and fuel gauge reading where it was with the other unit and somewhere where i think it should be.
Unit not getting hot at all i was a bit worried it may try and melt its way out of its little plastic enclosure .
So now waiting on spring to come so i can test it properly... think i may need to fill a Jerry can up first though just in case i have screwed the sums up. 😁
Unit not getting hot at all i was a bit worried it may try and melt its way out of its little plastic enclosure
.So now waiting on spring to come so i can test it properly... think i may need to fill a Jerry can up first though just in case i have screwed the sums up. 😁
- City
- Halifax
- State
- UK
Just a bit of a follow up with this as i filled up the 8 to the brim today mainly as i bottled it due to
A: The fuel gauge was reading just under a quarter of a tank and i was relying on my own sums.
B: I wanted a drive in the 8 as it was a nice sunny spring day with the mercury getting up to the mighty height of 53 F (This info is for the Florida posse, you know who you are 😁 )
Anyway it took about 8.5 UK gallons to fill it up which equates to 10.2 US gallons.
So in theory my 15 Gallon tank had 4.8 US gallon still in there before i filled up.
So the gauge rocketed up to F as it should and i reckon my theory is correct and if i let it read all the way down to E for empty then there will be approx 3.5 US gallons still in there.
As i have said all along, I can live with that quite happily, far more worried about running out of gas!.
So the only thing now is to check its reliability now that the salt is disappearing off the roads and the 8 will be getting used a whole lot more..
A: The fuel gauge was reading just under a quarter of a tank and i was relying on my own sums.
B: I wanted a drive in the 8 as it was a nice sunny spring day with the mercury getting up to the mighty height of 53 F (This info is for the Florida posse, you know who you are 😁 )
Anyway it took about 8.5 UK gallons to fill it up which equates to 10.2 US gallons.
So in theory my 15 Gallon tank had 4.8 US gallon still in there before i filled up.
So the gauge rocketed up to F as it should and i reckon my theory is correct and if i let it read all the way down to E for empty then there will be approx 3.5 US gallons still in there.
As i have said all along, I can live with that quite happily, far more worried about running out of gas!.
So the only thing now is to check its reliability now that the salt is disappearing off the roads and the 8 will be getting used a whole lot more..