The heater blower will work on the highest setting and not on the three lower ones. is there a fuse gone or a relay?

 

maybe. but my guess is the low speed fan switch needs replacing.

 

resistor pack on the firewall just past the heater core should be your problem. (at least that's where it's located on the land yachts and trucks I've driven. not so sure about the cougar.) we've seen this problem a few times. Like on my own 88 MGM and another 2002 sable here in this thread.

 

Here's some pics of the destroyed one from my car to give you an idea of what to look for.

If yours is this bad, you'll have to replace the wire harness like I did too. It was cheaper at the dealer for the parts.

 

thanks it turned out to be the resistor pack and it was located on the blower housing about 6 inches from the motor. thanks again for the help