94 Disco, 106K... aka "Old Faithful".

The AC in Old Faithful blows icy cold.
But on really hot days, with the AC on full cold and the blower motor set to 3 or 4... the blower motor stops momentarily then restarts a second or two later, sometimes 10 seconds later.

This will happen from once to several times a minute and keep happening. But only when it is real hot outside or the truck slows down in traffic after a high speed cruise. Almost like a fuse blows and resets itself. If the truck's lights are on, the lights that illuminate the AC console shut down too, and then come back on again as well.

Any ideas where the gremlins are ?

joe

 

Good question!!
What happens if you are running in the lower fan speeds? If OK, then I would say you have a blower switch failing, more specifically the resistors.
How about your electric fans, are they working with the a/c on?

 

It is common for the fan speed switch on DI's to do this, next time it happens wiggle the fan speed switch and see if the fan comes back on.

 

My 1998 Disco I does the same thing. I found that wiggling the switch turns it right back on. Must be a bad contact or something.

 

Same issue here, I tore apart my dash to look at the switch. Turns out it was shorting/overheating causing the internal plastic piece that holds the metal switch to melt and caused the connector to the wiring harness to turn black.