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Hello, I recently purchased a 2002 SC430. The button that controls the roof has ceased to function. It doesn't light up any more. No beeps or anything. I checked all fuses, button in glove box and the trunk and nothing. I also noticed that my temperature control on the driver side is stuck on 75, it will go up but will not go down. I've unhooked the battery for hours at a time and it just resets to 75 and does not go up. Also the the rear defrost button does not work. So I'm thinking the problem is with the HVAC unit where the roof button is located. Can this unit be repaired? Can the button be repaired? But has any one considered by passing the switch on the HVAC unit?
I saw where you could add a remote to control the top. That they utilize two wires under the Driver's kick panel to raise and to lower the top. I was thinking about connecting a two way switch to these wires and mounting it to the dash. I have a pic with some directions that was given in another forum and I was wondering if this is just simply calling for a ground to be connected to the green and yellow wire to open it and then a ground to the yellow and black to close it? I'll attach the pic with the info. Please advise.
If the problem is indeed the control unit at the console why not simply replace it with one you find on eBay and be done with it. I think 30% value of the car is at the top and if it fully works I think it's well worth $250 to restore it.
The replacement of the control unit is rather easy, simply pulling it out and plugging it back in. Just make sure the leather sides are taped so they don't get scratched when the unit comes out.
I probably will have to replace the unit eventually, especially when warm weather arrives, I won't be able to stand the 75 degree setting... I was thinking the two wires at the kick panel and a switch would be a good way to know for sure if it is the button on the hvac control or something else, and I could use it until I do order a different unit.
Am i correct that a negative would just need to be applied to the wires to operate the top?
I probably will have to replace the unit eventually, especially when warm weather arrives, I won't be able to stand the 75 degree setting... I was thinking the two wires at the kick panel and a switch would be a good way to know for sure if it is the button on the hvac control or something else, and I could use it until I do order a different unit.
Am i correct that a negative would just need to be applied to the wires to operate the top?
i would not connect a negative to the wires unless you have the wiring diagram and are confident you know what you are doing.
first, are there any codes or a CEL?
if you really think the HVAC control is the problem, see if you can ohm out the switches, I am not sure if that is possible but worth a look.
Martin, if you have never seen the top move and not sure what the problem is I think a good place to start is to check the car history(Carfax and Lexus service portal, etc) and see if there is any accident in its past. Chances are the control unit at the console doesn't go bad by itself. My guess is that there may be someone trying to fix the car and didn't properly wire it. If that is the case finding the wiring diagram may not help you much. Did the previous owner tell you anything about how to operate the top?
I really think that might be your best first step, since the convertible top has so many "safety" checks it has to complete before it will lower the top..
I tested the top before I purchased the car, it worked perfect. I didn't test the temperature button since it was cold that day or the defrost button. The next time I tested the top there was nothing, no lights no beeps. Checked in the trunk, checked fuses, checked button in glovebox. All was okay. Then I noticed the buttons on the HVAC were having problems.
I talked to the previous owner and he had no problems out of the top... The photo I shared is for a remote start, that also opens the roof. Looks like according to the write up a simple negative to those wires take the place of the switch on the hvac? But I want to be sure.
If the top and wiring all worked before and just the buttons on the console are giving you trouble now I would be very tempted to make an offer to the ebayer for $150 and see what happens. After all you will need those buttons to work sooner or later.
I tested the top before I purchased the car, it worked perfect. I didn't test the temperature button since it was cold that day or the defrost button. The next time I tested the top there was nothing, no lights no beeps. Checked in the trunk, checked fuses, checked button in glovebox. All was okay. Then I noticed the buttons on the HVAC were having problems.
I talked to the previous owner and he had no problems out of the top... The photo I shared is for a remote start, that also opens the roof. Looks like according to the write up a simple negative to those wires take the place of the switch on the hvac? But I want to be sure.
Make sure that the cover in the trunk is properly seated in the slot so that the sensor switch there will recognize it. Sometimes the covers will not seat well and that will cause the problem.
Make sure that the cover in the trunk is properly seated in the slot so that the sensor switch there will recognize it. Sometimes the covers will not seat well and that will cause the problem.
he said he has no light on the switch, if the trunk cover was not seated properly, I think he would still get a fast blinking red light. Does that sound correct?
01-12-17, 07:24 PM
SC430 Roof Button Bypass QUESTION
