naqvi

Please help, anyone.... I have been fighting with my daughter's AC for past two weeks. 1995 LS400. AC all of sudden quit working. I checked all the relays, checked the blower motor by connecting directly, it runs fine. The blower is not comming on. AC is working, and slow cool air comes out of vent but no blower. I swapped the ressistor from junk yard no help. Bought new relays and changed no help.Checked all th fuses one by one no help. The control panel display shows everything on, but no fan blower. Put on defrost or heater mode no air from upper side. Display has power and seems to be working fine. I even swapped the control panel from another one from Junk yard no help, still doing the same thing. It shows power, fan display and shows speed bars go up and down but no blower. I checked with my meter with car running and AC on the resistor out to blower motor has no power going out, I checked the resistor input plug, no power coming into resistor with or without AC running. I am baffled and must be something stupid from me that I am overlooking. Please help. Checked all the fuses under dash by left of driver side. No help.

Banshee365

Check your 50A HEATER fusible link next to the fuse box under the hood behind the battery.

naqvi

I checked the said fuse and replaced it, it was good but I replaced it anyway just in case.. no help. I also tried to review fault codes by pressing the two buttons on control panel. It goes to diagnostic mode. Runs the checks, all the lights come on like it should, beeps and shows 00 first, then starts a code sequence 21-29. I am baffeled. Never had so much trouble trying to figure something out. I also removed the relays and checked the pins where relays go. They all have current in them.

Banshee365

The blower power circuit is totally separate from the power to the AC amplifier/control panel. The power is fed through the 50A HEATER fusible link to the blower relay to the blower controller to the blower motor then to a ground behind the instrument cluster.

naqvi

Where is this relay located? If in fusebox next to battery in engine compartment, I have replaced this relay, shall I change it again, maybe bad from stock? when you say Blower Motor Controller, are you referring to resistor? if not where is this controller located? Thank you for your help.

Banshee365

Can you PM me your email address? I’ll send you the factory wiring diagram for the AC system.

naqvi

Its done on your PM in forum information.

Banshee365

So, EXACTLY what have you replaced? And, how are you 'checking' relays?

Remove the HEATER RELAY and check for power at terminal 4. You should see a small number 4 under the relay molded into the plastic, I think. With the AC on makes sure the compressor clutch is running. Try not to run the system with the compressor on and no blower, the evaporator will freeze.

naqvi

Ok. I will do as instructed. I sent you some details in your personnal enail. Thanks

naqvi

I removed the big black relay in Relay box next to battery. The larger tab closest to fender had power. I checked the three smaller tabs with AC running, the tab closest to fender did not show any power, the farthest one from fender showed power. Opposite of your email. Now what would be next step. Change the relay.? I am not sure the power coming is reversed, as no internal circuit was touched. Thanks

Banshee365

It’s possible that I read the diagram backwards. I was messing with my kid at the time. When I get home I’ll take a look and get back to you.

Banshee365

With the AC on, do you have any voltage to the white with red stripe wire or green with red stripe wire at the blower controller?

naqvi

Blower Controller? I have to take the dash apart to get to the back side of controller. I will try to do that in next few days. I checked the wires on Resisitor, to and out of resisitor no voltage with AC switch on.

naqvi

I have no power in those wires.

Bylan

Check for a car-phone box in the trunk. When the car-phone is activated, it sets the fan blower to the lowest setting. Itll be a black box with a coaxial cable attached to it on the passenger side of the trunk. Im hoping that is your problem