Heater A/C programmer

[Jim]

I have been selling Reatta parts for 25+ years and always learning something new.

'88 heater programmers are different from the '89-91s.

Yesterday I was using an '88 parts car to test programmers from other Reatta parts cars and the original one in the '88 tested good. The two I took from a couple of '90s would not change the air direction from floor to defrosters. Seemed strange that two of them would not test OK. I then got an '89 parts car and tested all of them again. Now the two I took from '90s worked in the '89 but the one from the '88 would not change air direction. I am guessing over the years I may have thrown away some good programmers thinking they were no good when in fact I may have been testing '88s in a '90 car or vise versa.

This morning I compared the wiring diagrams in the shop manuals from '88 and '89 and see there is a difference in wiring. One example, the ppl wire from the BCM going to the programmer, inside the programmer it goes to resistance 5V battery in the '88 but to resistance ground in the later programmers.

[2seater]

That is interesting. Back when I did a programmer modification with external vacuum solenoids, I am pretty sure I had acquired another one from someone, and noted either the wiring or tubing colors were different than the existing? I will see if I still have it but I think I initially chalked that up to being from a different model car. While I am writing this (slow typist) I now remember the solenoids inside the controller were also located differently relative to their tubing color.