So this weekend I went thru and pulled out the heater core in my boyfriends 99 Cherokee. After putting everything back together, I tested the heat.

At first, it turned on and started to run normally (no anti-freeze smell) and went thru speed 1-4. The next time I started it and went to drive it, the blower motor made a high pitch squeel then sounded like it was rubbing on the casing so I turned it off.

Now, It won't turn on inside the truck, but if i pull it out and put power to the motor itself, the blower will spin. I pulled the box out a second time this afternoon and made sure everything was plugged in/not getting pinched. Still no luck. After replacing the resistor and resetting the battery tonight, nothing except the resistor smoking and something smelling like its on fire.

Any ideas? We checked all fuses and relays and still no clues. Thanks in advance for the help

 

So I would say something is not grounded or wiring is pinched or wired incorrectly. I would buy a second resistor and see if there is a difference. If there was no problem prior to the heater core removal than I would say something with the putting everything back together stage went wrong. Trace the wiring, look for obvious issues, replace the resistor and pray a little! Good Luck!!

 

+1. I'd still throw another resistor in there first too.

 

Do u have any knowledge about what the wires look like down there? There are a few things that I didn't tear out that I wanna make sure they're in the correct spot..

 

http://www.jeepforum.com/forum/f11/f...tting-1261777/

It sounds like your blower motor is binding when installed, causing the blower motor to work harder, causing the wires to heat, sending heat to the BMR (blower motor resistor). That may be what you smell. Recheck you blower motor.

You can test a BMR by unplugging it and seeing if there is continuity between the 3-input terminals (1-TN, 2-LG, 3-LB) and the single output terminal (4-BK/TN). These wire colors are for a 2000xj. The FSM does not specify a resistance measurement, only that continuity exists. If it does then the BMR is good and you have other issues such as a bad switch, connectors, or wires. No continuity means that the BMR is bad a needs to be replaced.

BMR part number 04864957
Blower Motor 04886150AA

Ask me how I know...