Matt81

I installed a C4 blower motor last fall, and then reinstalled with the newer cage last week. On high speed after about 30 seconds, getting a distinct whine from the motor.

I reconnected the rubber duct that is intended to keep the motor cool. However, after running it for a while, the motor itself was HOT. Wondering if it overheated and that is causing the whine.

Does anyone known what the other side of the duct connects to? I just disconnected it from the motor and ran the fan on high for a few seconds with the engine off. No air coming out of the duct, so either it could be clogged or doesn't hook into an area that gets it's air supply from the blower fan.

I couldn't find any pics on the AIM that have info.

DUB

That hose is not there to blow air into the motor...if you look at where the fitting is attached to your evaporator core case. It is in a position that AIR passing by it...creates a suction to draw air from the motor.

If you stop and think about it....if you were driving in the rain and moisture filled air was obviously getting into the evaporator core case to some degree...then moisture filled air would be getting pumped into your motor...which we know is not good.

Now another thought can be that NOT all of the air the blower motor is giving to the evaporator core is making its way through it so it can be under some positive pressure....thus...allowing a small amount of air to make it to the blower motor. I guess it depends if you feel air coming out of the tube or not of any significant value where you can feel it.

That is my thoughts on that and of others disagree or have another idea...have at it.

DUB

Matt81

Interesting! I just tired up the engine to check for vacuum at the duct. No suction coming from the rubber tube. Even put some tissue paper over it in case the vacuum was so subtle my old thumb couldn't feel it.

No air in or out. Hmmmm.

Will hopefully have time this weekend to pull the blower motor again and replace big. Will dig into where the duct hooks in and see if it is plugged.

Does it hook i to the lower side of the evaporator core?

DUB

The rubber tube connects to a tube coming off the side of the evaporator core case . This rubber hose just slides on.

DUB

Matt81

Got it. Based off the amount of crud I pulled from the portion of the evaporator housing i could reach from inside the blower housing, I wouldn't be surprised if that tube is also plugged. Will take a peek soon.

Thanks for the guidance DUB!

DUB

We are both on the same page on that one. I am guessing that there leaves and crud that is effecting the air flow. Knowing that the tube coming off of the inside of the evaporator case is so low on it.

DUB

Duke94

This is my 79'

Matt81

Thanks form the birds eye view! That couldn't have been easy to get out.

That's a huge help to see what I'm up against. I'm guessing the rubber duct slides over a nipple that is fastened to the evaporator box by the bolt visible in the second picture?

Duke94

Yes, that's correct. The grommet looking end (shown disconnected in the photos) goes into the hole in the motor housing and the other end goes to the plastic nipple fastened to the housing. The evap box was out of the car which made it easy to work on.

DUB

And as you can see in the photos that 'Duke94' posted. The plastic tube is screwed to the evaporator case and it can be removed. Or you can leave it screwed in place.

If you have access to a borescope...you can look in that area and see what is going on due to it is much further down that your hand can reach.

I have used my borescope in this area to see how much crap is blocking the front face of the evaporator core.

DUB

Matt81

Wasn't able to pull the blower motor this weekend as getting to go on date night tonight with wife. Wanted to make sure everything was buttoned up, because taking the minivan out for a night on the town is a buzzkill!

Have a scope and hope to hear into it tomorrow to see if it is clogged. If anything like the top side, almost certainly so.

Duke94

Mine was filled with mice nest which was most of the underdash and hood insulation. This is the hole that the blower blows into. If you look to the outside edge, you can see all the cowl insulation piled up. I took a bucket full out of this area.

terry82

I would add a good ground wire ,anything better than stock.see if the motor runs cooler