Very little air output from vents & panel when fan is on HIGH

[Kerry_Gifford]

I have an '88 that I've had for over 10 yrs, and now whenever I turn the fan on HIGH, I get very little air coming out. In fact, it feels like the fan is still on LOW, but it sounds louder which tells me that it's is spinning higher. The low air output is the same when using HEAT or A/C. Switching to AUTO fan makes no difference either.

So, where do I start, and what to look for?

Thanks.

[jonlabree]

It's probably dirty or plugged with leaves and dirt.

Pull the heater blower and see if it is clean inside. Then pull the blower control and clean that out. I used Simple green and my power washer on the lowest setting. It improved the air by about 100%. One tip, make sure the drain under the blower control is open or you will get water inside the car.

[DAVES89]

Go to Reatta.net and click on FAQ then click on AC. All kinds of solutions there.

[Kerry_Gifford]

Thank you 63viking and Daves89 for your replies. I will pull the blower motor from the firewall on engine side and go from there. However, I'm not sure what and where is the blower control?

Thanks.

[jonlabree]

Here is a picture of both parts.

#1 is the control.

[Guest steveskyhawk]

Kerry,

Before you take anything apart first find out if the air is coming out of the defrosters instead. If the fan runs on high and the air comes out the defrosters then it is a vacuum leak. Mine did this after some major work. A vacuum line was disconnected near the firwall under the plastic valance. 5 minute fix

[Kerry_Gifford]

Thanks to 63viking for the pic which will help alot. And thanks to steveshyhawk for his tip for I will check that out too. Since I'm second owner, I know that this has never been cleaned out, so I'm going in for sure to check.

Thanks.

[Guest steveskyhawk]

Go with the simple, EZ stuff first!

[Guest steveskyhawk]

Go with the simple, EZ stuff first!

[jonlabree]

If your idle is rough then you may have a vacum leak.

[Kerry_Gifford]

Well, with limited view and using small mirror and flashlight, I was not able to see anything inside the blower assembly. I did clean the ECC module only, and did not hose out the blower assembly with water. And I checked and didn't see any loose/missing/broken vaucuum line.

I still have the low air problem from the floor, panel and defrost vents. So I'm thinking that I must have some kind of in-coming air restriction, but I do not know what is the air flow schematic is. Does anyone know where the incoming air is coming from? Or does anyone have other suggestions?

BTW, I eliminated a vibration whenever HIGH fan is on--the blower motor wasn't screwed all the way in completely.

Thanks.

[Barney Eaton]

The evaporator sits in the chamber between the blower and ECC module, ALL air (hot or cold) goes through the evaporator, if there is a restriction there, you will have a volumn problem.

Pull the ECC and look at the front of the evaporator. I believe you will find it has some sort of restriction. My car had a mat of cat hair completely covering the evaporator.

With a small flexable adaptor to my shop vac.. I was able to remove it. The process takes a little time.

[Kerry_Gifford]

Well, I've been thinking afterwards that something is amiss from 63viking instructions. I'm sure he meant to CLEAN the evaporator core, not the module <duh>. So, when I was looking thru the module opening, I was probably looking at the core which is on the wall of the interior compartment side (am I right?!?), and I recall it was kinda grayish looking and almost looked like it was a solid surface. Do you know if the evaporator core is made of aluminum or copper? If it is copper, why the gray appearance?

If the evaporator is where I think it is, then I plan on pulling only the ECC module and use the shop vac first to clean the evaporator, and then spray on Simple Green (a degreaser) and use a bottle brush to clean it and let it sit a minute and rinse off, and then repeat.

Cat hair?!? How did that get in there? :-)

Thanks Barney.

[jonlabree]

Yes, you are correct. I meant to clean the evaporator.

It has fins and should be cleaned carefully. I used Simple gree and let it sit for a few minutes before I flushed it.

BUT, as I said make sure the drain is open or you will get water inside the car. Put a little water in it and see if you can see it draining out the bottom.

[Barney Eaton]

Here is a sketch of the vacumn adaptor I used to remove crud from the front of the evaporator, the flexable vinyl tubing allows bending the tubing to reach most areas.

The second item is a trouble light for tight places. Mine came with a outdoor Xmas candle. 7w bulb, plugs into AC and you can drop in into doors and other tight spaces to get needed light.

[Ames63]

Kerry,

I have a simular problem, my blower fan works intermitently. The blower control that you cleaned is it an electrical connection or a mechanical piece?

[Kerry_Gifford]

Hi ames63. The control consist of two parts, a aluminum body with fins and a electrical module. There's no moving parts. My thinking is that the aluminum part is for air temperature detecting and the whole blower control is used for temperature data feed in heating & A/C functions.

I did clean this control, but it didn't appear to have any effect in air output, so maybe I might get a more accurate temperature reading display?? :-)

I will post the results of my cleaning work later.

[Kerry_Gifford]

I have air output!!

Of the two cleaning methods, I had concerns about using water since I felt that if there too much stuff to remove, it could clog up the drain hole and overflow into the car. Plus, I felt that it is best way to remove the junk is to pull it out of the evaporator core in reverse of airflow, thus vacuuming is the way to do it.

But I didn't think I could get the best cleaning job by working thru the brower control opening using something like Barney's neat homemade tool. So I decided to pull the blower motor out completely and use that opening to clean the core.

The core was really dirty, and I can see why there was no airflow thru the floor/panel/defrost vents.

I used Barney's idea of a 90 degree vacuum nozzle (I used a 1/2" PVC elbow), and it nearly fit inside the shop vac hose, and I used some tape to hold it place. It worked great, and I got the evaporator core all cleaned off.

I have taken some pics, but I don't know how to add them to my post. If someone wants to see them and can tell me how to post the pics, I'll do it.

Thanks again for everyone's help.

[Sweepspear]

I just went through this with my '92 Park Avenue after suffering for several years with no air flow.

Mine was so clogged with a fine black fuzz that when I first looked down into the A/C box I couldn't tell the evaporator core from the box itself!

I used both a shop vac with a rigged up extension, and compressed air.

The car is a joy to drive on a hot day now.

[Ronnie]

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[Kerry_Gifford]

Here's some pics of my cleaning.....

[Guest Squire Tom]

did all the above as suggested. core was not too dirty and all air comes through vents at 48F . recent change to r134 stuff. new blower and fan from autozone delphi part. hi fan on bcm 13.7 . still seems to me that at one time the older blower moved more air. what else controls blower speed ?

can the be an issue with the climate control system ?

[Guest steveskyhawk]

This thread is really informative. The A/C in my cars work pretty good with 40 degree duct temperature with 90 degree OAT. Cleaning the evaporator sounds like a grteat idea. In order for the A/C to work right the airflow volume must be right as well as the temperature.

2 QUESTIONS: 1) The wiring on the ECC power module seems to have the airbag blue plastic tagging. When removing the module to get the shop vac access should this wiring be disconnected or remain connected while the cleaning is done? I don't want to risk firing the airbag.

2) What is the best way to get access to the inside face of the evaporator in order to blow it out with compressed air. Vacuum may only be enough to get the loose stuff.

[Guest Squire Tom]

3 screws on the ecc came out easy and just kept it out of the way with a plastic tie wrap. don't know how to get to other side of evap. easily.

[Kerry_Gifford]

In reply to SteveSkyhawk, I'm really happy with the airflow I'm getting.

If you like, I can post a drawing from my Reatta service manual that shows the different airflows based on whether A/C, heater or both are in use. In the drawing, air is forced thru evaporator core, and depending on the position of a door, the air either goes thru the heater core or around it. So, if you were able to tear out some of the dash paneling and whatever else, you'll could be trying to get compressed air to go thru the heater core and/or a door before it ever gets to the evaporator core. I wonder just how much impact this may have for all this effort.

Also, I removed the both wiring plugs from ECC power module on two different occasion, and it didn't fire the airbag. If you're really concern, you can disconnect the battery although I didn't both times.

[Kerry_Gifford]

Sorry about posting pics that are too large.

I think I can edit that post and attach much smaller pics. Does anyone know if I will be able to delete the large ones? If so, please let me know how.

[Kerry_Gifford]

In reply to Tom_Wasil, I presume that you still having airflow restriction? If you look at my third pic showing the firewall, at the very upper left part of the pic, you can see part of the fresh air intake opening with the wire-mesh screen underneath the slots. I vacuumed off this when I cleaned the core. Maybe yours is dirty or clogged?

[Roadster90]

For Future Reference:

I remember when I cleaned (used water)my housing out that I was instructed by folks on the forum at that time to park the car on a downward slope or jack up the rear end so that the dirty water would drain out easier....

When I did clean out the housing (using a tool similar to Barney's) using water and vacuum I did remove some "trash", but it really did not improve air flow that much....I just gave up and accepted the low air flow.

Since this situation has risen again, I might try a new module and fan motor....

[Guest steveskyhawk]

Yesterday I removed the ECC from both of my cars without removing the brace or unplugging the wireing. I had made up an adapter for my wet dry vac as per Barney's drawing. Once exposed the evap core looked like new with no obstruction on either car. I sprayed them down with windex and vacuumed the liqiud and maybe some dust out who knows.

At this point I dont really think anything else is necessary except to enjoy the cars.

The reason I was concerned with the A/C airflow was two fold. Obviously it is hot here in CA and need optimum performance; but the other reason is that one of my cars had sat under a tree and the vents by the wipers was full of leaves etc when I got it. To my pleasant surprise they were both clean as a wistle.

[Guest Squire Tom]

91 has same ties on the ecc .

will the motor ever receive more than battery voltage - although i guess that is the most that is available.

probably down to the directional door issues as i did move the adjustment on the arm to push wide open ac and the arm did move back the other way when i increased the set temp.