Hi guys,

I have a strange one for you. As some know, I had an freon leak in my 90 AC with C68 last month and it dumped all my R12. Ok, so I replace the condenser and convert it to R134. So far so good. The thing is as cold as I could expect, no problems there.

But I noticed that since I made the repair, the fan will not blow as strong as it used to. Almost like there is no Max blower speed.

Even if I put the auto air on max setting (10), it just blows so, so, definately not as much as it used to.

I starting reading my service manual and it says that there is supposed to be a fuse somewhere near the blower moter (on the pass side engine compartment). I could not find it! Looking at the wiring diargram, it looks to my amature eyes that this fuse might provide power directy to the blower (maybe when it wants full power). So I figure that fuse might be blown. Where is this fuse?

The rest of the system seems to work normally. Everything comes out of the correct vents, recirculate air works, etc. I did not check the fuse that is supposed to be in the regular fuse box, since the rest of the system seems to work fine.

Anyone ever find this 'hidden' fuse that is supposed to be near the blower motor. The diagram makes it look like in should be on the fender side of the blower motor? Who knows, maybe this diagram is really for a ZR-1 and does not apply to the regular L98, but it sure does not seem to indicate that!



Or do I need to do a service on the AC control panel according to the tech tip?

No codes in the system.

Thanks in advance,

 

If you remove the two top bolts that hold the plastic radiator fill tank and move it out of the way, you'll see what looks like a small black relay housing mounted to the firewall/driverside of the blower motor. The fuse is inside the black housing.

 

Had the same trouble with my 90. Turned out to be the blower speed resistor. It's mounted to/in the evaporator/heater core housing under hood, passenger side, (near auto trans dipstick handle) it has a 4 wire (covered with flex loom) harness with a rubber boot plugged into it. Unplug the harness and remove the 3 screws and lift it out and it will reveal 3 different size coils that regulate fan speed by current resistance controlled by AC controller. Mine had 1 burned coil and my fan was weak. Replaced it and viola, problem solved.

If you find no problem there, there's also a blower speed relay on 90's located next to upshift relay mounted motor side of drivers side fender well near brake master cylinder and battery. The blower relay is the one closest to battery. May be worth checking it. Good luck.