We have a 1990 Honda Accord DX and the AC and the heater are not working properly.

Most of the time no air is being blown at all, but sometimes the air will blow (no known pattern). When it does work the AC does get cold and the heater does get hot. Here's what typically happens:

When you start the car, it's not blowing any air (on a rare occasion it will blow at start, but mostly not). Then as you're driving it will start blowing air out of no where (we always leave it on). However, the weird thing is, if driving at low speeds, the air will be really low. If at higher speeds, the air will after a short time, blow high/normal. Then when we slow down or stop it will blow low again.

 

From your description, the blower motor brushes are worn and loose. They will sometimes make contact and run, other times not. A good test is to thump the blower housing firmly w/ your hand when motor fails to start. If motor immediately starts to run, worn brushes are confirmed.

Installation is not too bad a job. I did this on a 90 EX years ago. The ECM/TCM module must be unbolted and rotated towards middle of car. The blower module must be rotated ~90 degrees (bottomside to the rear from memory).

There should be a 90 Accord shop manual link in Online Manuals post of DIY forum.

good luck

 

Thanks for response. Why remove the TCM? Is that on the floor and the blower unit behind the glove box?

 

TCM/ECM module is removed to make room to extract the blower motor housing, containing the blower motor.

good luck

 

Ah. Makes sense.