The key to this problem lies in the wiring harness. Specifically where the wires are placed when connected to switch...
U need to copy the factory manual on this hook up..
the harness is marked A*B*C*D*E.. each wire is placed according to color in its corresponding letter slot...
The harness melts (I think) when the resistor craps out..


I did this w/ mine and had no issues...
Fan speeds are Low/ med 1/ med 2/ High

 

Plez see the reply I sent to the questioner at bottom of your post.. good luck Jim....Kirk out

 

Mine did this too... turned out to be the MAP.... manifold absolute pressure... sensor.. located IFO driver on the firewall..
the sudden jump is related to vacuum spiking, my own opinion here....
the map sensor is pricey... get the Delco.. good for 100K. miles


1993 XJ... 4.0L

 

Dealership has different part numbers for '93 vs '94 PCV and CCV on the valve cover. Anybody know what the difference is between the years?

 

So my blower quit working a few daya ago so I checked the fuse. Melted. So I yanked it out and replace it with another 30A fuse and tried it out. Worked just fine for a few minutes and then I shut off again. Checked the fuse again, this one is melted too. Any idea why the fuse is melting after running the blower for a few minutes. And no I don't mean blown, the plastic housing is melting on the fuse

 

My blower circuit problem was the resistor. The replacement I bought was also defective. Once I ruled everything else out, I basically decided to start over with that. I ended up buying one from a different parts store, plugged it in and was good to go.

As for the wiring harness, I have a 2000 and I didn't have the slightest bit of melting with my BMR or harness. From what I've read that's a common issue with the earlier model years. If the blower itself were to short out, that might cause issues with wiring, but I'd hope the fuse would go first.

 

mistake

 

Thanks. I will take a look at that tomorrow. I changed the resistor some time ago and it made no difference.

 

My problem was the plug going from the coil to the distributor but I went ahead and replaced the distributor, rotor, plug wires, and coil just in case. This was the plug wire going from the coil to the distributor. Fixed my issue. I was constantly getting a error code for cam shaft position sensor and crank shaft position sensor. Then a few times while driving down the highway, the engine acted like it shut off for a split second. My guess is no spark at that particular time due to no spark making it to the distributor points.

 

Still need this info^

I just noticed right now that the cylinder head I pulled from a '98 cherokee, casting 0630, doesn't have the hole for the rear coolant temp sensor.
Is this normal, and where is the coolant temp sensor if its not there?

 

they moved the hole to top of thermostat housing which bolts to the head. If yours is located at the rear of the head, u can simply extend the wiring to thermostat housing.

Some people actually drill and tap a hole on the rear of the head. Totally up to ya

 

My harness had two sensors, one at the t-housing, and another at the block.

 

Drill and tap it then.

 

I meant I figure I could just use the front sensor only.

 

Use just one sensor/sender when the vehicle is wired for two?