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Temperature Gauge...what to do?

tnjeff

NAXJA Forum User
Location
Tennessee
Hi all. This is my first post here, though I've been lurking for awhile. I've got a bunch of questions but I thought I'd start with this one:

The temp gauge on my 96 Cherokee hasn't worked since I bought it so I'm finally getting around to fixing it...maybe. After doing some searches I see that 96's are supposed to have a sending unit in the back of the head. On mine, I see a plug from the wiring harness, but no sending unit (see picture). The plug is just hanging there.
plug.jpg

It seems like I read somewhere that some 96's could have the sending unit combined with the temp sensor (in the t-stat housing). Has anyone else heard of this? I suppose that another possibility would be that it has a 97 or later head.
So I guess I'm trying to decide whether to go ahead and replace the sensor, hoping that it will fix the gauge. It seems to run fine and gas mileage is usually decent, so except for the gauge not working I wouldn't think the sensor was bad. Any thoughts?
Thanks,
Jeff
 
Yep, that looks like the wiring that's used with the sending unit at the back of the head. Mine is more like a plug, I just can't find anything to back there to plug it into. Maybe I just need to go ahead and replace the sensor in the t-stat housing and see what happens. I 'm wondering if the sensor is different for gauges and warning lights. Thanks for your help on this Stryker.
 
hubs, I'm beginning to think that might be the case. Thanks for the link. I'll check it tomorrow and post what I find.
Thanks guys.
 
So I have an issue I put a tac cluster in my Jeep and I have no temp gauge the idiot light worked the 1 time it started to over heat .So I got a sensor from parts+ and low and be hold ....... nothing happend they told me there is only 1 part number for the sensor on my 95 WTF 20 bucks in the toilet is this true I would like to have a temp gauge
Thanx :greensmok
 
muddy -

There are 2 types of temp senders. One is for cars that have an idiot light (basically,
it's a temp-regulated on-off switch). The other sender is for cars that have a temp gauge
(it's a temp-regulated variable resistor). Externally, they look almost the same.

Are you certain that you got a temp sensor that is compatible with a gauge?
Verify the part number of the sensor you got via a web search.
 
muddy -

There are 2 types of temp senders. One is for cars that have an idiot light (basically,
it's a temp-regulated on-off switch). The other sender is for cars that have a temp gauge
(it's a temp-regulated variable resistor). Externally, they look almost the same.

Are you certain that you got a temp sensor that is compatible with a gauge?
Verify the part number of the sensor you got via a web search.
 
Sorry to resurrect this thread so much later. Just to follow up, my head number is 0630. I actually have the part that KD3NE linked to above, the temp sender for gauge. It was in the glove box of the Jeep when I bought it. Just to see what would happen I boiled some water, plugged the sender in, turned the key on and dropped the sender into the water. Gauge didn't move. Should that have made the gauge read?
 
Ooohhhh, (face palm). So I could wrap a wire around the threads and ground it and it might work, at least to test it?
 
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If you want to see if the wire is for the gauge, turn on the car, touch the wire to a ground point, and see if the gauge pegs to the right. The gauge uses a small coil that produces a magnetic field which tugs the needle, with the one-wire sender varying the resistance. With the wire disconnected you have open circuit so no juice to the coil, no magnetic field, and gauge is dead left. With the wire directly grounded, the coil has a closed circuit with no resistance, resulting in full magnetic field and gauge pulled all the way right.

If that works you'll need to find somewhere to install the sender. If there's not a hole in the head, most people extend the wire to the thermostat housing, drill and tap 1/8 NPT in the flat spot, and install the sender there.
 
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