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Heat in Jeep not that hot

F

F1504x2

NAXJA Forum User
Location
Fuquay-Varina, NC
We have a 88XJ 4.0 and live in North Carolina so the temp has been around 30 degress in the morning. The heat is only warm to cool and really will not heat the interior within my 1/2 hour drive to work. The temp is running 180-210, but closer to 180.

I think i know the problem. We have two cooling fans on the engine, one is the engine fan on the 4.0 and one is the electric fan and the electric fan runs all the time since the thermostat on it went bad. Can i put a manual switch on the electric fan to control the engine temp?

Thanks.:us:
 
First things first - check your coolant level. No coolant, no heat.

Also, when you say thermostat, are you referring to the thermostat on the engine block that controls coolant circulation? If so, that's something that needs to be addressed.
 
F1504x2 said:
the thermostat on it went bad
Click to expand...

If the thermostat is bad, why not just replace the thermostat?

I may be misunderstanding something here, but rigging a switch to turn the fan on and off manually when you already know what the problem is seems contrary to logic.
 
anthrax323 said:
First things first - check your coolant level. No coolant, no heat.

Coolant good enging thermstat changed over the summer.

Also, when you say thermostat, are you referring to the thermostat on the engine block that controls coolant circulation? If so, that's something that needs to be addressed.
Click to expand...

What ever controlls the electric fan went bad so the fan run all the time, when ever the truck is runing.

Thanks
 
casm said:
If the thermostat is bad, why not just replace the thermostat?

I was told the thermostat is built into the Jeep fans and don't really want to spend to much on a toy/second car.

I may be misunderstanding something here, but rigging a switch to turn the fan on and off manually when you already know what the problem is seems contrary to logic.
Click to expand...


Not if it's done right.

Thanks
 
F1504x2 said:
Not if it's done right.
Click to expand...

That wasn't the point I was making - what I was saying was that if you know what the issue is, fix the issue properly rather than trying to make something else work around it; not that your idea wouldn't work. In any event, it sounds as though you were referring to the thermostat for the fan, not the engine (which is how I read it initially), which is where the confusion came in.

Either way, it sounds like the problem (fan always on, coolant not warming up) is known and you have a plan to work around it... So what exactly is the question again? It's not exactly clear as to what advice you're asking for.
 
Efan should only run when the engine temp reaches something like 217 degrees.

Efan is controlled through a relay I believe and also through the coolant temp sensor, NOT the thermostat.

One of those two things has likely failed.
 
casm said:
That wasn't the point I was making - what I was saying was that if you know what the issue is, fix the issue properly rather than trying to make something else work around it; not that your idea wouldn't work. In any event, it sounds as though you were referring to the thermostat for the fan, not the engine (which is how I read it initially), which is where the confusion came in.

Either way, it sounds like the problem (fan always on, coolant not warming up) is known and you have a plan to work around it... So what exactly is the question again? It's not exactly clear as to what advice you're asking for.
Click to expand...

With both fans running keep my engine too cool so my heat in the Jeep is only cool/warm?
 
I'm not entirely sure the electric fan running constantly would be sufficient to cause this issue, especially if the temp is 180+ (still plenty hot for your heater to work).

Have you checked your coolant level?
 
You have a "temperature switch" in the radiator that controls the auxiliary fan operation--that is how the closed systems operate.

Also, and most likely what you are witnessing, is that the auxiliary fan runs when the a/c compressor operates. Now, if you have the HVAC control set to defrost, the a/c compressor runs to dry the air and the auxiliary fan runs.

I would start with replacing the thermostat--yours isn't working correctly. Install a Stant SuperStat Premium 195 degree thermostat. That should resolve your issue. If it does not, post up and we will go further, but 180 degrees shouldn't be happening.
 
joe_peters said:
You have a "temperature switch" in the radiator that controls the auxiliary fan operation--that is how the closed systems operate.

Also, and most likely what you are witnessing, is that the auxiliary fan runs when the a/c compressor operates. Now, if you have the HVAC control set to defrost, the a/c compressor runs to dry the air and the auxiliary fan runs.

I would start with replacing the thermostat--yours isn't working correctly. Install a Stant SuperStat Premium 195 degree thermostat. That should resolve your issue. If it does not, post up and we will go further, but 180 degrees shouldn't be happening.
Click to expand...

Will do. I think i installed a 180 over the summer so i'll try the 195.

What do i need to check to repair the electric ran? We removed the AC Unit a while back and relocated the alt. to the top.

Thanks, JOhn
 
Test the switch, it is next to the lower hose outlet on the radiator. The switch should close when the coolant has reached 190 F--this is a low temp but it is taken on the cooled side of the radiator.

There is an auxiliary fan relay on the driver's side fenderwell, test it, it could be stuck on. If you pull it the fan will stop.
 
joe_peters said:
Test the switch, it is next to the lower hose outlet on the radiator. The switch should close when the coolant has reached 190 F--this is a low temp but it is taken on the cooled side of the radiator.

There is an auxiliary fan relay on the driver's side fenderwell, test it, it could be stuck on. If you pull it the fan will stop.
Click to expand...

Thanks:us:
 
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