I recently tried to use the heat in my 1990 JDM turbo2. The heat was working last yr around this time but now it work randomly. I've researched and have found nothing that helps in my particular case and I'm not gonna pretend I know the ins and out of it all. So to start this all off I will say the blower motor turns on randomly, I noticed it turns on more when it's warmer outside and when the fan speed is in the middle and the heat is not all the eay up. When it's cold cold and I actually need it, it's rare that it turns on. I can hear two very distinct clicks coming from under the glove box (RHD) at high and ex-high. The logicon seems to be functioning fine in terms of the button functions and where the air is going. The last time it turned on I was driving and it turned off within 5 mins of turning on. I was going to just replace the motor since it wouldn't hurt regardless. Any info will be highly appreciated.

 

Your blower motor might be clogged with dead leaves and other debris. I would suggest removing the motor assembly (its held in by 3 screws) and checking it. Alternatively, given that your car is 35 years old, the brushes in the motor might also be worn. I had similar problem in my '90 several years ago. Here's a photo of how my blower motor looked when I removed it.

 

I found your post and it seems to be the most similar so that's what I decided to go with. You mentioned the shift was longer. Did you have to modify at all or was it direct plug in?

 

Not exactly sure what your asking, but I did eventually replace the blower motor with one that I bought off Rock Auto (https://www.rockauto.com/en/moreinfo...t=6916&jsn=433). The replacement motor worked out just fine. The only thing was that the replacement motor had the electrical connector on short wire leads rather than on the motor itself.

 

Update: 2nd blower motor put in and turned on, was 50 degrees outside yesterday. Left for work this morning and it was 40 degrees and it didn't turn on. Turned on about 15 mins into drive after the car warmed up for 10 mins. Seems temperature is my issue. Possibly the thermo resistor? Ideas?

 

About a year after I replaced my blower motor, I started having intermittent motor problems again. I checked all the relays at the blower unit and they all checked out good. I bought a new used Logicon off Ebay and that solved my problem.

 

Guess I'll keep an eye out for a logicon or maybe rebuild. Cuz it seems to work above 48 degrees. Anything below is a dream.

 

Does it work when the blower speed slider switch is on high or all the way to the right?

 

Ya, it adjust fan speed and everything. It just doesn't turn on if it's too cold out. Once it warms up around 48-50 degrees, it kicks on.

 

Have you checked to see if your getting power to the right pins on the relays and resistors when it’s cold?