Have replaced the blower control module twice in my '89 convertible (220,000 miles, daily driver) in under two years. Straight wire blower, and it blows, so I assumed it was the module. Heat and A/C initially work with new module, but lasts only a few months, then no blow. Hey, it's a convertible so lack of A/C is no big problem (even in SC), but it does get cold enough to be annoying. Don't want to buy another module unless I am confident it will last. Suggestions?

 

This is an issue not just with corvettes. Your blower fan is causing resistance and causing the module to overheat. Most likely the reason your module keeps going bad. You will probably notice that your module has signs of heat damage. Replace both and happy motoring. Maybe some others can confirm this. But I had the exact experience with other vehicles. My latest truck had 250k on it when I sold it. Just prior to this, I replaced the module twice and it kept failing. I jumped on the internet and found that information. I replaced the fan assembly along with a third module and never had another problem. My guess is that after years and years and so many miles, the fan bearings go bad. This makes it hard for the fan motor to spin, causes resistance and extra heat, and it causes the module issue.

 

^ Great guess, in my opinion.

Not sure how easy or difficult the blower motor is to get to on an '89 vs. my '96, but I recently pulled my blower motor (which was getting a little noisy, I thought) and shot some WD-40 followed by white lithium grease into the outboard bearing area and it quieted right down.

This may not be a "permanent" fix, but if I have to pull the motor every couple of years and re-lube it (vs. replacing the motor with a new one), I don't care, as it's such an easy job.

 

Excellent info. When the second module crapped our, I suspected something else was the cause.

 

Will replace both. Of course, the heater core is also bad, so will be working from both sides of firewall. Have been "piped around" the core for some time now, but cold weather is coming, and it is time.

 

Yeah that’s the perfect time to do it. You’ll have it all apart anyway.

 

I had problems of my blower motor power wire connector melting a few years ago. Don't remember if it was doing that before I replaced the factory blower motor or started after I replace the failed motor. But had to clean melted plastic off of the terminals in the blower to get it working again. This was a few years ago. And used a metal pick tool to force the spring terminals inside the wire harness down so they would put more pressure on the male terminals inside the blower motor just in case there was poor connection.

Then earlier this year the blower motor stopped working. And ended up finding the plug melting that goes to the control module. The plastic had melted and glued the plug in place. Luckily I was able to pry it out with a flathead screw driver. Luckily the module looked mostly okay. And I used sand paper to clean the male terminals in the module.

The wire harness plug was melted some on the purple wire that I think is the power. But I sprayed everything down with contact cleaner and was able to get the plug in. As I had thought I might have to buy a new plastic piece as the wire terminals seemed to be okay, just the black plug melted some. I may still see if I can find just the plastic plug part so I could replace that part since the wires are still good. But did think if I did that that I might should also replace the purple power wire that runs to the blower motor as the insulation on the wire seems to show the wire gets hot too.

Anyways, not sure if the aftermarket motor was causing any of this, but went ahead and swapped it out at Autozone as a "warranty" replacement just in case.

Are there any brands of blower motor that are good?

Will have to replace the radiator cooling fan motor soon as it's starting to make noise, and really hope that plug doesn't later start melting causing my fan to stop working leading to a protentional over heating situation. And that cooling fan motor wire harness connector is in a place that would be hard to replace if it were to melt because of crappy motors.

What's inside a blower or cooling fan motor could cause the power wire to run hot? Could this also be just a poor connection with the wire terminal and connector in the motor?

 

Wow! Your problem seems much more serious than mine. Terminals and connectors don't just melt from age or neglect. They have to be near a major heat source, experience quite high current loads, or have arcing. Arcing could result for poor contact between the "male" and "female" ends of the connectors due to looseness or corrosion, or ???????. So far, all my connectors are good, although I handle then gently, so as not to break any.

Replaced blower motor and control module today, and all works good. Hoping that it last longer than the 3 mos. on the last control module.

 

Colter, that sounds like a ton of fun. I’m by no means any authority on this whatsoever but I do believe it’s all caused by the fan/fan motor. Once they become harder to spin, I think the whole system heats up from resistance. The harness, control module, and connectors seem to pay the ultimate price from the heat. Being that you replaced the fan, I would probably attribute your further *** aches to the new fan being chinesium junk and failing prematurely, or something else in the mix was crispy and causing resistance. I seem to recall when I had issues with my truck guys on the Cummins forum were saying to stay away from the auto zone/Duralast fans. I wish I could tell you what would be the best brand but I don’t know. Honestly you may want to call one of the OEM used parts suppliers (Mirrock, etc) and see if they have an original fan for your car out of a lower mileage car. Hell, see if they can snip it at the harness coming in and sell you the whole thing. I harp on this in every thread it seems like now but replacement parts ain’t what they used to be. I have to say as of late, I haven’t had issues with Avance Auto/car quest parts. I also like NAPA for brake calipers (eclipse line you get a nice coating), u joints and sensors. Their echlin line of sensors I have never had an issue with. I believe I got my fan and new module from NAPA when I did my truck. I sold it shortly after so I can’t report on durability.

 

When I found the control module plug melting as my blower mower stopped working earlier this year, I fixed that, though may try and buy a new plastic piece for the wire harness, and I had the blower mower replaced at Autozone under warranty just in case the aftermarket blower mower I put on like 6 years ago was the problem. So no issues since. The new blower mower is continental brand. The thing is I only drive like 2 or 3 times a month, so not really a lot of miles on the blower mower I replaced 6 years ago.