Evaporator blower motor noise

freesaints · 06-18-2020, 02:31 PM

I've got an aftermarket Classic Auto Air AC system in my 1987. I noticed that there's quite a bit of noise coming from the blower motor in the smugglers box. When I peeled back the foil tape and looked in the hole, it seems as if the fan is tilted. I can push on it and it's got some give. Looks like maybe a bracket inside the housing broke, causing it to tilt and perhaps causing it to rub on the side?

Any thoughts on how to remove the top of the housing to inspect further? I notice several screws which appear to hold the two halves together but it also seems bonded with some kind of epoxy. I'd rather not disassemble anything that would require me to recharge the system, etc since I'm not set up to do that myself. Thoughts?

freesaints · 06-19-2020, 05:58 AM

Any thoughts?

KOH · 06-19-2020, 07:06 AM

The top of a stock evaporator box can be removed without disconnecting the AC hoses. The epoxy you see may be something like RTV - if so you can cut it with a utility knife.

On my '87 the two halves are joined where the silver tape is. I do not have the screws that your pictures show. May be they modified an evaporator box to fit that fan assembly?

If it's a modified case you can peel back the tape and you should see either small screws, or sliding clips that hold to case together (its been a few years but I think there are 5, but don't quote me). Once you un-clip or unscrew these fasteners the top half should pull off. Just be careful with your thermostat switch probe; replacing it is a PITA.

freesaints · 06-19-2020, 07:24 AM

KOH, considering I'm using an aftermarket fan inside the box, I wouldn't be surprised if it was modified in some part. One example is the hole in the top that I can tell had been cut at some point. Looks like there might be two ways to open the two halves: unscrew and cut through the epoxy, or go further down and peel back the tape and look for the clips. If I could undo the screws, it looks a lot easier to access and less invasive. I was hoping that if I did that I'd see a broken bracket which is causing the fan to tilt but before I just started cutting I was hoping someone else's setup looked similar that had done this before. Being in TX, the last thing I want to do is start fiddling around and then ruin what cold air I do get (although noisy).

KOH · 06-19-2020, 08:31 AM

Freesaints,

The screws - or clips - holding the two halves together are a little fiddly (tight space), but are straight forward - remove them and the whole top lifts off. That might be easier than cutting through the epoxy, if nothing else because you won't have to replace the epoxy when finished. I'm sure they installed the fan in the cover first, then when the epoxy dried placed the assembled top half onto the bottom of the case.

If the inside of your case is like mine. the noise you hear may be the fan striking the evaporator itself. I had that on my car and ended up replacing the fan. The old fan gouged the evaporator.

Just be gentle with the thermostat switch probe; don't bend or kink it. Good luck with your investigation and repair.

ganun · ganun's Garage

I have an 87 with the retroair now classic air system and there is no hole on the top of the evap housing. That said the aftermarket hi perf blower part of their kit, replaces the top of the factory housing and is attached with troublesome clips along the edges to the lower part. See my thread from last week "AC REPAIR AFTER 8YEARS " .
I'd say it's very difficult to reattach and seal the top half to the bottom side. Recover the freon and pull the evap as a unit, sorry to say.