1992 Sc400 Heater/ac Control Unit Dead

[gategem]

The Heater/AC Control Unit on my 1992 SC400 went dead. It is totally inoperative and none of the indicator lights illuminate. I would like to check the fuse for this unit but I don’t have a manual and I don’t know where the passenger compartment fuse box is located. I would appreciate any help you can give me.

[lexus082]

The fuse box is located on the driver's side kick panel. The climate control unit is on the same fuse as the cigarette lighter. Before you replace the fuse check the cigarette lighter to make sure nothing dropped down into causing the fuse to blow. Its labeled CIG (15amp fuse).

[gategem]

The fuse box is located on the driver's side kick panel. The climate control unit is on the same fuse as the cigarette lighter. Before you replace the fuse check the cigarette lighter to make sure nothing dropped down into causing the fuse to blow. Its labeled CIG (15amp fuse).

Thank you.

[LLS]

There is an under the hood fuse that is 100 amp and also has control over that area of the car.

[kavvick]

Exact thing happen to my 92. Tried everything with fuses ect. The unit is most likley dead. I went on Ebay and bought a new one for $120. Try a local junk yard or ebay. I had to suffer four weeks of new england winter without heat ;b

[gategem]

Actually lexus082 solved the problem for me. My gf is the primary driver of the car and she took out the cigarette lighter since she didn’t want anybody smoking in the car and she never covered it. There was a penny in the lighter that blew the fuse. We didn’t know about it because we didn’t use the cigarette lighter and I was unaware until lexus082 told me that the fuse also was for the environmental control unit. Removing the penny and changing the fuse solved the problem.

Once again thank you for your help and hopefully some day I will be able to help someone else the way you have helped me.

[JohnnyTurbo]

Thanks much from a new member of the forum, 99 SC400 here. Love the car, in mint shape. The ac went blank yesterday. I thought that I was in for replacing the controller that I saw on ebay for 200+. I checked your forum and sure enough, I won't be putting my mechanical pencil in the lighter hole anymore.

Thanks everyone who helps out. John

[iamxpl]

does that same fuse tie in with the rear defroster?

[iamxpl]

oh my god thank you! i just got the car. and now i have a working ac.

[dogbert22]

I know it's an old thread, but I had exactly the same problem, including the penny in the cigarette lighter. Replaced fuse, spent the penny, and All Is Well now. The owners manual doesn't mention that the AC controls run off the same circuit as the cigarette lighter...