In the SC300/400 manual on one page it has the simple instructions as posted by pheonix88;

"POWER TRANSISTOR
Removal & Installation
Remove glove box. Remove screws and power transistor. To
install, reverse removal procedure."

In another section it clearly states that removal of the A/C unit is required to access the transistor, and also says "remove engine", which cannot be correct.

The diagram above also shows that the transistor is integral to the evaporator which is a real b1tch of a thing to remove, that is the white plastic case behind the glove box.

 

How do you test the blower resistor and power transistor?
https://www.clublexus.com/forums/sho...t=blower+motor

 

To test you have to take the resistor out and measure the resistance, I have the specs at home which I can post if no one else does later. The resistor if I remember right measures around 3.4ohms, it was afterall the transistor, I never did find it, I just sent it to Lexus and they fixed it for me, couldn't go through the winter w/o it. The transistor if you can find it is a bit harder to test, you just have to hook it up to a test circuit, but if the resistor fine and the a/c unit is fine, its definately your transistor.

 

How much did Lexus charge you to fix it all?

 

I can't really remember, around 300 canadian which if you convert it is 200 us, (or less). The part itself is 100 canadian for either the blower resistor or the power transistor, rest was labour, and I swear they like to overcharge a young person like me driving an expensive car. I just live with it now, sometimes wonder if it is the case because if it is that is not really right!

 

has anyone fixed this problem yet. im having the same problem. thanks

 

Just about to tackle the same problem myself. My climate control fan is on full and changing the speed setting makes no difference.

Surely the dealer couldn't remove the evaporator and replace the transistor and put it all back together for only $200.

Evaporator removal is a major job, so either you don't need to pull the evap to get to the transistor or they didn't replace the transistor.

Does anyone have any service specs on checking the transistor and the resistor block?

Did anyone find the relay that was discussed earlier in the thread? With my limited knowledge I would have thought that the transistor supplied full power and the resistor block supplied the variable voltage.

Cheers
Matt.

 

Bump, anyone had to do this yet?

I am going to pull the resistor pack and if it has continuity then it's probably okay, I suspect it's the transistor pack has failed closed.

Matt.

 

Funny to see this thread. Mine just started doing the same thing about a week ago. Very annoying. It's all or nothing air.

Any additional info would be great. I'm dirt poor right now so may have to live with it.

Plus, most places charge like a flat $95 fee just to diagnose the problem before they even do any repair.

 

The part# is 87138-24060. It is $75-90 depending on how well you can negotiate with the dealer. Very simple installation. There are AC DELCO and DURALAST out there for $50 but they take a long time to special order.

 

man you have to remove the engine to fix a simple fix!? lol thats crazy, stupid manuals.

 

Marcman18, what's the part number you are referring to, is that the resistor pack or the transistor?

Cheers
Matt.

 

the part# was for the resistor. I just changed mine and it didnt fix the issue. So tomorrow I am going to buy the transistor. The job is not that difficult just takes time.

 

Cheers. Will be interested to see where you find the transistor module.

Is your fan on high speed only?

Matt.

 

My fan is locked into HIGH SPEED only. I ordered the blower transistor today. The part# is 88750-24050. It cost me $160. Hopefully this is not too difficult to install.