ThatchP38 said:

Still working on the 2002 P38. I have previously posted and fixed the ABS issue with a new (used) fuse box replacement, all is good there.

I have replaced the broken heater core using the short cut method.
My issue is with the hevac control unit. Mine did nothing basically and did not light up but the seat heaters and windscreen heaters work.
I replaced the unit with a used one which works nicely but I lost the seat heaters and windscreen heaters. So I put the old one back in and both things would not work and the light would not come on above the buttons.

I checked fuses and relays and still nothing.

Any ideas? Maybe the wiring came loose at the pins?

Click to expand...

ThatchP38 said:

Ok I'm an idiot. I started the car and then everything worked. I didn't realize it had to be running to operate the windscreen heater and seat heaters.
On the plus side I just had a new windscreen installed and ready for winter

Click to expand...