intermittent heater

[Channel595]

im pretty sure its the switch for the heater but im not certian, it will either work like 100% or not work 100%. one time when it didnt i restarted my car and then i couldnt get it to not work and im not sure on this particular car but when i first got it, it would turn on really slow, is that normal? intermittent problems are a bitch to find.

[Towncar]

.....and im not sure on this particular car but when i first got it, it would turn on really slow, is that normal?

Yep, "really slow" is the new thing. The engineers figured you don't want an undesirable temperature blasting at you, so they worked it out so that the system will try to reach "your" desired temperature before blasting it.

What year was your's again? I'm thinking this might just be the infamous Blower Speed Control transistor solder problem.

[Channel595]

91 towncar

[Towncar]

Have you looked at the Blower Speed Control yet? There's a huge transistor on one side that's not soldered with hi-temp solder, it melts, blower acts odd, then locks on high.

Re-soldering it with better solder does the trick, if that the problem..
There's a writeup at LincolnsOnline, and I have something on my freebie site too (right column).