1985 Corvette Blower Motor Issue
#1
TheCorvetteBen
Thread Starter
1985 Corvette Blower Motor Issue
So I recently got the AC fixed in my 85 (YAY!) and since I am using it now, I have noticed that my blower motor only works on the highest setting, and even on HI the air flow is pretty lame. I purchased a new blower motor resistor and installed it, but that made no difference. What do you think is the fix for this? I would love to have lots of air flow out the vents, Thanks!
#3
Burning Brakes
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I believe that is the way they are, on my '85 it is extremely weak as well unless it is on HI. If it makes any difference the AC on ours was using R12.
By the way I have been enjoying your videos on your project and your previous corvette projects as well.
By the way I have been enjoying your videos on your project and your previous corvette projects as well.
#4
Race Director
Sounds like the evap core is covered in debris. Seems like you can pull the blower resistor and see most of it through the hole. Apparently some folks use things like brakeclean and compressed air to clean it off. Personally if that's the case I would replace it, but I have all the necessary tools and experience to do it myself.
#6
Melting Slicks
Do you have a Schematic for the Blower circuit?
If so post it and we can walk you through the Electrical circuit. I have no idea How hard the Blower push's air through the vents on your "year" but I will say that any Leakage in the Ducting and or Blockage at the Heating/Cooling coils will effect air flow. A few years ago I removed an Evaporator from my Honda, and it was loaded with all kinds of stuff.. newer cars have Cabin filters that mitigate this problem.
If so post it and we can walk you through the Electrical circuit. I have no idea How hard the Blower push's air through the vents on your "year" but I will say that any Leakage in the Ducting and or Blockage at the Heating/Cooling coils will effect air flow. A few years ago I removed an Evaporator from my Honda, and it was loaded with all kinds of stuff.. newer cars have Cabin filters that mitigate this problem.
#7
Race Director
The air goes through the system from the blower motor side of the evaporator. The only way to see if the evaporator is clean is to remove the blower motor.
#8
Le Mans Master
I just finished getting my blower motor going again. As was stated the '85 does not flow a lot of air but if everything is okay it does more than adequately. My problem was almost no air flow at all, my resistors all ohmed out at almost double what they are supposed to be and the motor was sluggish. I replaced the resistor and the motor and now it is flowing good. The relay is most likely the cause of the lack of slower fan speeds.
#9
Burning Brakes
My 86 flows great on high but will not blow at any other speed. I replaced the bias resistor but it made no difference. Do you think mine needs a new relay as well?
#10
Le Mans Master
Considering what you have to do to check the dash unit I think I would replace the relay first, it's not that expensive and an easy change. It fixed mine. Pull it out & test it, if it does not click when you cross terminals then it is bad.
#11
Race Director
#12
Le Mans Master
You are right, I really dropped the ball on that one, sorry to the OP for misinformation
#13
Melting Slicks
So I recently got the AC fixed in my 85 (YAY!) and since I am using it now, I have noticed that my blower motor only works on the highest setting, and even on HI the air flow is pretty lame. I purchased a new blower motor resistor and installed it, but that made no difference. What do you think is the fix for this? I would love to have lots of air flow out the vents, Thanks!
My 85 has all speeds working, i only use the low speeds in winter with the heater on. The high speed in an early C4, is pretty much like low speed on a normal or more moderrn car.
I have been thinking of doing a motor swap for something that spins faster, be a lot harder to make the fan recess hole bigger for a larger fan.
Is Winter here in OZ, the fan speeds are ok for Winter, C4's have great heaters.
Very bad in summer where you want to be blasted by cool air when getting in a hot car that has been cooking under a hot sun.
Man i think Corvette bodys should be designed and built in the USA,
Weatherstrips designed and made in Japan (who has ever had to replace a weatherstrip in a Toyota they last forever)?!?!?
Engines by Mercury marine (they made the LT5)
A/C by Toyota, a small micro car Toyota can have ice cold a/c driving through Death Valley in the peak of summer. 138F temperatures and no overheating issues the damn coolant temp doesnt move, we can really learn a lot from some of these overseas manufacturers.
I mean who doesnt have one "worried" eye on the coolant gauge of a Corvette, there is a fine line between normal and *&#@ that is too hot.
We should not have to switch of a/c in summer while in heavy traffic, just because the coolant system is barely up to the task in an early C4.