92 Ls400 Blower Motor Resistor Diagram/location

[flyguy1996]

The low setting on my a/c would occasionally start blowing at medium speed then revert back to blowing at low speed from time to time, irregardless of whether it was on auto or manual. Meaning, even if I selected low speed, it would still blow at medium speed. Yesterday, it stopped reverting and now my fan runs no slower than medium speed all the time (unless switched off). My guess is it's the blower motor resistor, so I'd like to replace it. But I can't find any diagrams that show where it's located or how to replace it (I've checked the forums here, but couldn't glean enough to help).

Does anyone have experience replacing the blower motor resistor on a 90-92 LS400, and if so, can you explain the procedure? Would appreciate a diagram, too, if someone is kind enough to post one here.

Thanks in advance!

Tony

[jeffls400]

The blower motor resistor is mounted inside the evaporator / blower motor housing. I think you would have to remove the entire assembly to switch out. It resides behind the glovebox and its removal would require evacuating the a/c system.

[wwest]

The low setting on my a/c would occasionally start blowing at medium speed then revert back to blowing at low speed from time to time, irregardless of whether it was on auto or manual. Meaning, even if I selected low speed, it would still blow at medium speed. Yesterday, it stopped reverting and now my fan runs no slower than medium speed all the time (unless switched off). My guess is it's the blower motor resistor, so I'd like to replace it. But I can't find any diagrams that show where it's located or how to replace it (I've checked the forums here, but couldn't glean enough to help).

Does anyone have experience replacing the blower motor resistor on a 90-92 LS400, and if so, can you explain the procedure? Would appreciate a diagram, too, if someone is kind enough to post one here.

Thanks in advance!

Tony

If I remember correctly the 92 has a power transistor that controls blower speed up to MAX wherein a relay kicks in to eliminate even the slight voltage drop of the transistor in saturation. I don't remember where exactly the power transistor is mounted but I would suspect the driver circuitry in this case rather than the transistor itself.

[flyguy1996]

Oh boy. This doesn't sound like fun Maybe it's best to bring it in and have them fix it. Just didn't want to spend $500 in labor if it's a $30 part and work I can do myself.

[bright]

The low setting on my a/c would occasionally start blowing at medium speed then revert back to blowing at low speed from time to time, irregardless of whether it was on auto or manual. Meaning, even if I selected low speed, it would still blow at medium speed. Yesterday, it stopped reverting and now my fan runs no slower than medium speed all the time (unless switched off). My guess is it's the blower motor resistor, so I'd like to replace it. But I can't find any diagrams that show where it's located or how to replace it (I've checked the forums here, but couldn't glean enough to help).

Does anyone have experience replacing the blower motor resistor on a 90-92 LS400, and if so, can you explain the procedure? Would appreciate a diagram, too, if someone is kind enough to post one here.

Thanks in advance!

Tony

Dear Tony,

I have the same problem in my 1995 SC400 now. I was wondering if you are willing to share the solution to your problem.

Thanks,

Bright