madmanxj

My aux fan on my radiator is not working. Have tested the fan, checked the fuses and i changed the temperature sending unit. Does the sending unit run just the guage or does it run the fan too i am talking about the one located on the back of the head by the firewall. There is a temp sensor on the thermostat housing too is that the one i need to test? if so how do you test it? Any other suggestions as to what may be wrong? I have looked wiring over everything seems well i really dont want to peel open factory looms. This is on a 95 xj sport. Thanks.

Programbo

I know all that temp sending unit back by the firewall on the head does is work the temp gauge on the instrument cluster so maybe the other one is the one you need to look at.

bigshow1983

9 times out of 10 its your fan relay you can splice into the wire that goes into the clip for your fan and run a wire to your postive connector and then a groung some were if your fan comes on then its your fan relay and if it dont come on then its your fan its self that aint working

Solomon7

The one on the thermo housing is what turns on the fan.
So you already jumpered the fan and it works then?
If you've eliminated all but a sensor, the one on the thermo is cheap cheap.

jeepxj19

I would run power directly to the fan to see if it works, then work back, the fan will turn on when the temp gets to 195? Or is it 210? Or will turn on while the ac is on, if u tested everything and it still doesnt work, run power straight to it and hook up a toggle switch and control it manually

madmanxj

Fan does work i tested it with a power probe. Where is the fan relay located? I have not changed the sensor on the thermostat housing. But the local auto parts store has one in stock so i might as well change it anyways.

lurk520

I believe the thermostat opens at 210 unless it's been switched out with a 190. I don't think the aux fan comes on unless you run the AC.

jeepxj19

its suppost to come on with ac or when temp gets to 210. i just changed mine out not to long ago

Char92dj8

Had the same problem on my 89, it was the relay.

lurk520

I used to have an 86 Olds, and when I bought it the PO had the aux fan hardwired under the dash with a toggle switch. It was kind of cool cuz I could turn it on when ever I wanted, but eventually I had it wired back up correctly.

bigshow1983

ok so just bypass the relay and put a toggle in it and manual control it just as easy as flipn a switch on and off

Iceman09

I'm having the same prob on my 88. Where is the relay located? The relay is the only thing I haven't checked.

posjeepxj

thermo stat is normally 193
aux fan kick on at 217
or when ac/defrost is on

i run my aux fan off a relay and thermo switch with toggle option (all 10ga wiring and thermo switch that i installed). i also removed the mechanical fan and run an electric as the main. the main i kicks on at 193 and off at 185. aux kicks on at 205 and off at 195. my aux fan has only ran twice that i have heard. i was 90 degrees and was doing some very slow wheeling

my point is stock cooling fans and pretty much cooling system sucks. upgrade

madmanxj

Well she gets up about 220 to 230 while climbing hill on my way to work. She runs about 210 - 220 crusing but at a idle she will heat up almost to the red. I have changed thermostat to a 160 and changed radiator too. I need to know where the relay switch for the fan is. I guess i am gonna go for a new water pump this weekend too. Shes not leaking but may not be enough pressure.

posjeepxj

160 thermostat is making the problem worse not better. it doesnt allow the coolant to stay in radiator long enough to get cool