AC Control Unit dot dash dash
Thread Starter
Intermediate
Joined: Aug 2020
Posts: 37
Likes: 2
From: New Orleans
AC Control Unit dot dash dash
Just got a 94, and have and issue. I have read some of the thread, but I think I may have 1 difference....and would like see if anyone knows what it is. When I start my car the AC blow hard from the defrost (common) and the display show a dot and dash dash. None of the buttons work. I have removed and cleaned the control unit and replaced the blend door actuator. Here is the difference..... When my key is in the second position (ACC I think), he unit comes on and works absolutely perfectly. I can change the vents, temp, basically do it all, but as soon as the car starts it goes to the default dot dash dash and doesn't work.
I read that it may be the programmer module, so was going to replace that next. Any other suggestions? And one last question.... would it be OK to remove one of the fuses to stop the hard blow to the defrost to drive while I sort this out? Fogs up my windshield. Im in the south so no need for heat or ac right not. Just put the top down and cruise.
Thanks in advance.
I read that it may be the programmer module, so was going to replace that next. Any other suggestions? And one last question.... would it be OK to remove one of the fuses to stop the hard blow to the defrost to drive while I sort this out? Fogs up my windshield. Im in the south so no need for heat or ac right not. Just put the top down and cruise.
Thanks in advance.
Drifting
Joined: Apr 2020
Posts: 1,925
Likes: 610
From: Orange, CA
Wow, just had this same exact issue happen on my '94 today! Must be something in the water.
It's absolutely the capacitors inside the programmer going bad. It happens on all of them, just a question of when. The fact that it seems to work sometimes is just dependent on the system voltage managing to coincidentally fall into a range that the bad capacitors can still handle. With the car off, you're on battery voltage - draw (so ~11.9V or so, probably). With the car on you're at 14.1V (probably).
Yank the programmer, replace the capacitors...or send it to BATEE to fix, depending on how comfortable you are with a soldering iron. I have to yank my radio to replace the backlight bulbs that Delco-Bose decided in their infinite wisdom to solder to the radio PCB anyway, so guess we're both yanking our center consoles.
It's absolutely the capacitors inside the programmer going bad. It happens on all of them, just a question of when. The fact that it seems to work sometimes is just dependent on the system voltage managing to coincidentally fall into a range that the bad capacitors can still handle. With the car off, you're on battery voltage - draw (so ~11.9V or so, probably). With the car on you're at 14.1V (probably).
Yank the programmer, replace the capacitors...or send it to BATEE to fix, depending on how comfortable you are with a soldering iron. I have to yank my radio to replace the backlight bulbs that Delco-Bose decided in their infinite wisdom to solder to the radio PCB anyway, so guess we're both yanking our center consoles.
