Your numbers above are pretty close only off around 15 degrees. First guess I would say the gauge is good but the sender in the engine is not correct. With the engine warmed up read the sender ohms-- block to term on sender.

edit- went out and checked a gauge I have using the "Willcox 4 pot license plate gauge checker" and you are closer than 10 degrees dialing in exactly 100ohms = 150 deg. and 220ohms = 95 deg.

 

Thanks for the responces. I plan to try again this weekend to get it working. Before I take the gauge's back out (which is a pain with my radio installed), would you think that since the resistor test gave me the readings above, that my gauge is working (meaning that I probably have that washer on the 3 oclock stud)? and that my sending unit is either bad (It is new, but I guess it could be bad) or there is possibly a sending unit grounding problem (when I changed the sending unit, I didnt look to see if the hole had tape or some other insulator in there)?

 

I was typing while you were. :-)

I will check the reading this weekend straight off the sending unit to see what it is, then go from there. I will let you know what i find.

I truly appreciate your time.

 

I think your gauge is OK and the washer is in place. You could have a poorly grounded sending unit but I would bet you just have the wrong one.

 

Me to....Good luck

 

Yeah, I ordered a sending unit from Zip that is for a 70 350. However, my engine is a CE engine with 0 as the last digit. I assumed that it is a 70 replacement L46 (which was what the car came with). I havent taken it apart, though, so I guess It could be a 60 327. With the power that it has, I really believe that it is a 350/350 engine though and I have the correct sending unit. I will let you know what i find out this weekend. Thanks again.

 

Dwnnchs: See now I've got you in the gauge thing for good! This will really take the heat off me!

I was watching this thread go by faster than a freight train.

I pulled some of the sample data that I have here on the temperature gauges for the 1968-1972 cars. The first one I pulled showed the following requirements.

Gauge ----------- Ohms
Reading -------Required
100 ------------ 220
1st Mark ------ 109
210 ------------ 79
2nd Mark ------ 65
250 -------------51

The problem you are going to have here is matching these numbers to a sending unit. So far even though I carry the sending units made by Lectric Limited, I have not found a single sending unit that produced the correct output! None! Some may be close, and even we are guilty of having them listed on our site as correct! They are not! When you get your new sender, boil it and test the output before you install it. You may find that the unit you are using is closer to correct than your new one. Maybe you’ll be lucky (we were the other day on one) and get one that is close.

There is a way to match the dash unit to the sending unit but you have to do this by changing the resistance across the two poles of the ground circuit on the gauge. I did this for 77sleeper on his crate motor change over. We matched the dash unit to the output of the new sending unit.


To add to this dilemma, over time the oil in the gauges will dry out and thicken. This will decrease the responsiveness of the gauge.

For my records, the gauge tested was our test number T102 and it was a NOS gauge not a reproduction or a used unit.

 

OK....so Ive been reading along for a while due to my issues with my 72 temperature gauge. I am new to posting......

My problem is that when I start my car the temperature gauge continues to climb past 250. It appears to climb at about the same rate as the engine warming up....but then keeps going.

I have tried pulling the sending unit wire and the gauge goes below "0" whan attached with key on just above "0". When grounded it goes past 250. (I have not been to RS for risistors.....its on my list)

New sending unit....no tape or sealant.

BTW the car is not overheating as I have put a temp gun on it.

Any suggestions????