Temp Sending Unit Test/Fix

[rollbar]

Temp sending unit test:

http://www.youtube.com/watch?v=JZ6-ahK5t0c


http://www.youtube.com/watch?v=JZ6-ahK5t0c

[tufcj]

The temp sensor uses resistance like the fuel gauge. It's even regulated to 5 volts thru the fuel gauge. See this:

http://www.jeeptech.com/electrical/gauges/index.html

Bob
tufcj

[rollbar]

Thanks Bob, I'll check it out but first I would like to find the fuse for it and check that.

[rollbar]

OK,
1. Where is the fuse for this?

2. I think I will run a mechanical temp as well
http://www.street2mud.com/albums/M170Start/100_1779.sized.jpg

3. I have a 195* stat in now, should I go to 180* being in the desert, but winter here lasts just as long.

Thanks,
Jim

[Old Rugged Crosser]

Thanks Bob, I'll check it out but first I would like to find the fuse for it and check that.

:happy2::happy2::happy2:
JIM
Have I got your attention now?

Look all you want for that fuse but you will never find it. That is because there isn't one.

As Bob said the temp gauge reads resistance. It is a theresister. It sends back a ohm reading.

[rollbar]

I got it. Some one told me to look for one on JeepForum and I knew I have never seen one on the block (inside), I just thought I was missing something.

Thanks,
I'll keep checking it out. I'm going to print the link and take the dash off and check my wiring, while I'm @ it, I might as well install a mechanical temp gauge. :)

P.S. Where's the BEEF!

[Old Rugged Crosser]

Jim-- Here is a suggestion, put that wire that you pulled off of the sender and find that wire at the gauge and take a ohm reading cold and then take a reading while it is hot. You should get 2 different readings. If so your sender is working.---- There's the beef!

[rollbar]

Thanks Larry/Bob

[rollbar]

OK, installed a new temp sending unit and will add the fluid on Monday (the temp housing was leaking so I re-tapped the holes and installed the correct length bolts from the PO as well as cleaning up the housing/intake).

I do also want to install a mechanical gauge.

Question (just to be sure), the mechanical gauge goes here, correct (pic below).
http://www.street2mud.com/albums/M170Start/100_1779.sized.jpg

http://www.street2mud.com/albums/M170Start/100_2190.sized.jpg

After I get it completed I will fire it up and see if both gauges work, if not then I will continue to trace it down.

[rollbar]

Is this right/wire color on the sender?

http://www.street2mud.com/albums/M170Start/100_2165.sized.jpg

[tufcj]

Looks right, mine is a purple wire. The power for the temp gauge is regulated thru the fuel gauge, I think it gets 5 volts. You could check for voltage at the strap that comes from the fuel gauge. If you have an analog meter, you may see the power going on/off quickly. That's normal. If there's no voltage to the temp gauge, the bad news is that you have to replace the fuel gauge, or do what I did and just forget the factory gauge and get a mechanical one.

Bob
tufcj

[msalaba]

74

The guage should have 19-21 ohms between terminals "A" and "S"

According to the manual, the temp circuit is powered throught the fuel guage circuit.

Your fuel guage work?

There is a 3-amp fuse one up from the bottom right corner on the fuse panel that powers both the fuel and temp guage circuits.

The fuel guage contains a voltage regulator circuit referred to as a CVR in the manual. If this is bad, neither guage will work.

I would start by looking for power to the guage, then a bad ground, then check for open/shorts.

Hope this helps. Can't wait till you get the bugs out and on the road!

[rollbar]

Thanks I'll try to print them.

Very soon she will be on the road and I'll do a U-Tube video :)