No heat on 1999 jeep wranger

You need to check the Blower resister. This is what makes the different speeds. It is located below the dash on the passenger side. Has at least 4 wires going to it. There is most likely a trim panel you will need to remove to see it. Check to see if the connector is burnt. If ti is both the resister and the connector will need replacement. As far as buying and returning a blower motot beware as most places will not take back electrical parts for this very reason. Best to diag and get the right part the first time.

Hi pklilly
dave here

the best solution for this problem is to buy a new blower motor at the auto parts store or a used one at the wreckers and keep the receipt.
without tearing everything apart unplug the old blower and plug in the new one.
if it works tear the old one out and put the new one in.
if it does not work return the blower and get back to me.
this of course assumes you have checked the fuse (both sides) with a trouble light(continuity tester). if there is more than the blower running off the fuse just make sure whatever else is on the fuse is working