I just replaced my instrument cluster voltage regulator because I was getting high readings on both my temperature and fuel.

I followed this guide and used the same parts.

K-Jet.org | Instrument Cluster Voltage Regulators

Afterwards, my fuel gauge is working perfectly, however my temperature gauge is reading at approximately 1/3, around 7 o'clock. Is this a normal reading?

It was that way this morning when I drove to work ~hour, but it was coldish. Coming home today it read the same and I was in traffic and it was hot! If this is an abnormal reading would the culprit be the actual gauge or the temperature sensor?

Thanks for your help!

Justin

 

I just filled up the tank to check!

 

I have a newer 1991 cluster, so I may be off, but here are my experiences:

I took of the regulator board that keeps the temp gauge in the middle at the time unless it is really cool or really hot. The result is that my gauge is usually right about there when running on cooler days, and gets to about the 9:30 position on warmer days. If your car does not have the temperature compensation board, I would suspect similar behavior. What year is your 240? Gauge cluster looks... 70s? So I'm not sure if your car ever had a temp. compensation board.

Alternatively, it may be right on, and the thermostat in your radiator may not be closing up all the way to get the engine as warm as it should be. That is something I am considering on my own car. But I haven't noticed any ill effects.

EDIT: Re-read your post--If you can get your hand on a temp sender, you could switch that out to see if that made a difference. There are ways to verify the gauge itself... but I've never attempted them. I'll look in my books and get back to you.

 

Yeah it's a 1980, and I believe the regulator boards weren't put until 1986 so I don't have one of those.

Hopefully it is sitting in the right spot! What would you consider a warm day for you? I live in Ontario, and today was hot for me, (27C-30C which is 80F-86F, 50% Humidity) and the gauge sat at that spot the whole drive home from work. I was definitely expecting it to go to at least 8 or 8:30

 

I think your gut is right--80F at 50% humidity ought to bring it higher than that, or I would think that. But I'll pay attention while driving to see what the gauge does.

From the Green Books:



Then on the next page,



If you can find yourself a resister at an electronics shop, this would not bee a terribly hard. Online, Radio Shack says they have 'em. (68 ohm 1/2W 5% Carbon Film Resistor pk/5 : Resistors | RadioShack.com)

There are two procedures here... the first one is if the temp sender unit has only 1 lead, whereas the second procedure is what to do if your sender unit has 2 leads. I suspect yours is the first.

But if you can do this, you can conclusively figure out if the gauge is okay or not.

 

Thanks for the info! That's definitely a very easy test for me to do, resistors are not hard for me to come by