Blower fan speed changing on it's own??
 

So my fan speed only stays constant when on high:confused: I am wondering if this is an issue anyone else has had before?
I have searched and searched and nothing that really hits the nail on the head other than there is a resistor under the glove box that may or may not control the fan speed?

If I have the fan speed on 1 then it will go to max speed for a second then back to the 1st setting which is starting to bother me:mad: It does not seem to follow a pattern.

Any input would be apprecieated.

is it on auto....??? also it has a temp sensor inside the cabin if its on auto it adjust to the temp that you set on dial...is that what you are talking about ???

Maybe your power transistor is shorting itself out and just going bad. That could explain its erratic behavior. From what I've seen, anyone who's a/c only blows on the lowest setting has a problem with their transistor.

Then again, i've only seen this with older SCs and you have a 97?

Yes a 97, I am following what you posted in this thread...https://www.clublexus.com/forums/sc-...n-speed-4.html

It is starting to get worse by the day, I vote that we need a stickey for this issue.

No that is not the issue as it does it on auto and manual mode.
It seems as if the middle 2 settings don't work just full blast and low but low just switches back from low to high.

voltage regulator,,had that happen in a mercedes benz it would blow either super low or wide open no inbetween...okay just look it up its called a blower motor control relay on a lex

I am looking in to the relay but I just can't seem to figure out how the relay would do this? It's a 10.00 part so I am not out much if it does not work and the v.r I is what I thought may have been bad in the 1st place but I have had it tested a few times and it has been fine.