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The resistor is on the back of the original gauge in the console. They can be purchased at a few of the regular Camaro parts vendors. It's been awhile since I looked through the catalogs. But I think it was Year One and/or Classic Industries?
Nick - Almost everyone carries the ceramic based replacements for the rear of the gauge.

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Thanks guys, I have looked but only seem to find the 86 ohm resistor. I tried googling it and also came up empty also. :(
 

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86 ohm is all your going to find, if you want a 91 like mine you have to make it yourself out of multiple resistors either in parallel or series, or in the form of a potentiometer (adjustable resistor). Go down to radio shack and get a 0-100 ohm pot adjust it to whatever you want, remove the original (don't lose it) and put one lead on one of the gauge terminals, and the other on the opposite one and your done.
 

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Thanks guys, I have looked but only seem to find the 86 ohm resistor. I tried googling it and also came up empty also. :(
84 Ohms - Ceramic colored Pink is correct value for fuel gauges
86 Ohms - Ceramic colored Orange is correct for temp gauges.

You will have to add resistance as noted above to push the needle toward the hot side or make up for having the wrong gauge sender in the block..
 

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86 ohm is all your going to find, if you want a 91 like mine you have to make it yourself out of multiple resistors either in parallel or series, or in the form of a potentiometer (adjustable resistor). Go down to radio shack and get a 0-100 ohm pot adjust it to whatever you want, remove the original (don't lose it) and put one lead on one of the gauge terminals, and the other on the opposite one and your done.
Thank you Mark, Unfortunately I'm a huge idiot when it comes to electronics but I will see what I can come up with. Thank you again sir.

84 Ohms - Ceramic colored Pink is correct value for fuel gauges
86 Ohms - Ceramic colored Orange is correct for temp gauges.

You will have to add resistance as noted above to push the needle toward the hot side or make up for having the wrong gauge sender in the block..
Thank you Brian, I have ordered two different sending units both for console gauges and neither one will move the needle past the lowest cold mark. :(
 

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If you ground the terminal to the sender to the engine block, or exhaust manifolds (just disconnect the wire at the sender and touch it to bare metal on the engine) does the gauge in the console peg high? If not you may have other issues besides the balance resistor.
 

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If you ground the terminal to the sender to the engine block, or exhaust manifolds (just disconnect the wire at the sender and touch it to bare metal on the engine) does the gauge in the console peg high? If not you may have other issues besides the balance resistor.
Yes it pegs the gauge to hot if you ground the wire.

Do you remember what watt potentiometer you used?
 

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Also, you should be able to do a continuity test from the hex on the sending unit to a ground to see if the sender is grounded.
John
Thanks, I think it should be good, I didn't use any sealer or teflon tape when installing the second unit. The gauge reacts exactly the same as the first unit even though they read slightly different ohms cold.
 

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I'm trying to remember... Didn't original OEM gauges have an internal resistor? Isn't that the real issue? I think I also remember that only one manufacturer of replacement gauges had the internal resistor. Maybe I'm thinking of internal vs. external resistors.?.?
 

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I'm trying to remember... Didn't original OEM gauges have an internal resistor? Isn't that the real issue? I think I also remember that only one manufacturer of replacement gauges had the internal resistor. Maybe I'm thinking of internal vs. external resistors.?.?
Original AC/DECO had external resistor cards of wound copper wire.

First generation restoration gauges from CHQ - Classic Head Quarters also used external resistors but made from ceramic shunts. The second generation from CHQ are internally resisted.

OER brand from Classic Industries were always internally resisted.
 

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I don't remember the watt rating of the pot I used, but the original wire wound resistor doesn't have much capacity, the wires on it are about 30 gauge and can't carry much more than a half amp without burning up and probably only carry a couple of milliamps when powered, so any 1/2W or greater resistor will work fine.

A dead short from battery voltage to ground thru a 91 ohm resistor will draw about .15A and produce 1.85W of power (heat), but the 91 ohms is wired in series with the coil inside the gauge which is probably on the order of several hundred if not a thousand or more ohms that will cut down both current draw and power output to less than 1/2W.
 

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I don't remember the watt rating of the pot I used, but the original wire wound resistor doesn't have much capacity, the wires on it are about 30 gauge and can't carry much more than a half amp without burning up and probably only carry a couple of milliamps when powered, so any 1/2W or greater resistor will work fine.

A dead short from battery voltage to ground thru a 91 ohm resistor will draw about .15A and produce 1.85W of power (heat), but the 91 ohms is wired in series with the coil inside the gauge which is probably on the order of several hundred if not a thousand or more ohms that will cut down both current draw and power output to less than 1/2W.

Thank you sir, I will see what I can come up with. :)
 

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Thank you sir, I will see what I can come up with. :)

Update...

I picked up a 2 watt 100 ohm potentiometer & finally tried it today. I set it @ 91ohms and it did help but I was still barely getting the gauge to move to the cold mark. I then just opened it up to 97 ohms which was the most it would go and it would finally move the gauge to the 1/8 mark when hot. I then added another 50 ohm resistor to it in series and played around with it for a bit and ended up @ 129 ohms to get the gauge to work the way I wanted it to. So a 150 Ohm potentiometer would have been perfect.

It's 101 out today and I went and drove the car in the heat. The gauge will sit right in the middle while driving it @ I think around 185-190* If I stop and just let it idle with no airflow it will heat up a bit and the needle will move up a tick of two depending on how long I just sit. Once I got home I let idle up against the garage for a while and the gauge went to the 3/4 mark and once I shut it off I turned the key back on to watch the gauge and it never made it to the red but did go to the gold mark and I checked the head temp with a in-fared temp gun & it showed 227* so I can only assume it will go into the Red @ around 230*.

I am not sure why my gauge needs so many more Ohms to function but I am happy to say it's working great now. :hurray:

Thank you again to everyone for the help and especially Mark C. I would have pulled out whats left of my hair with out your help. ;)
Thank you again,
Nick
 

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Is there a way to do the opposite? My guage reads too hot compared to its actual temperature. I’ve tried 3 different senders with no luck. I’d love to be able to wire something in line to adjust the reading. Thanks.
 

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Is there a way to do the opposite? My guage reads too hot compared to its actual temperature. I’ve tried 3 different senders with no luck. I’d love to be able to wire something in line to adjust the reading. Thanks.

I dont see why not. Find your self a 100 ohm potentiometer (I bought mine on ebay) and play around with the ohms a bit until you can get it to read where you want it. Maybe start out @ 50 ohms and adjust it as needed.
 

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Thanks!
 

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My water temp gauge was pegged way below 'cold' when I'd turn the key, even though I followed the American autowire classic update kit instructions. I switched the pink (12v) and green (water temp sender) wires and now it works perfect.
Do you remember which blade the pink wire goes on? I have it on the cross bar at the top of the "T".
 
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