Author Topic: underdash a/c  (Read 9314 times)

davids

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underdash a/c
« on: September 01, 2011, 17:27:51 »
removed heater core,blower motor on underdash a/c has movement in and out does anyone know where to get relacement motor? also would like to replace front cover on the underdash unit can any one tell me where to go? The unit is factory.

George Des

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Re: underdash a/c
« Reply #1 on: September 01, 2011, 23:59:32 »
My advice is to replace your existing a/c blower assembly with a Spal unit. Made of plastic and provides much more volume of air more quietly. You'll probably have to canabalize a cover from a donor a/c unit. Don't believe you will find any new ones lying around anywhere. For info on the Spal units do a forum search. Hope this helps.

George

Raymond

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Re: underdash a/c
« Reply #2 on: September 04, 2011, 12:50:47 »
I just installed a SPAL blower for the A/C and a new motor on the defroster blower.  If you removed the heater core, you also removed the defroster blower.  The motor for the defroster is available for $150 from Buds but someone recently posted a cheaper solution.  Although, having used the Buds unit, it could not have been more simple or successful.  

The SPAL blower for the A/C was another story.  It is larger than the original by just enough to cause some fitting problems.  You'll have to drill a couple of screw holes and cut a corner of the assembly's frame for fitment.  Then it will take some strength to get it all crammed back in place.  Solid installation though.  

With mine, I carefully identified the speed control connectors and matched them to the original, and bench tested to be sure.  Now that it is installed, the fan speed switch in the under dash unit does not give me low speed.  The low speed position gives me medium speed and the other two positions provide, medium, and high as they should.

I searched the web and vintage air sites pretty extensively and did not find an exact replacement for the underdash face or vents.  There are some that are close, but not close enough.

Just things to look forward to.
Ray
'68 280SL 5-spd "California" Coupe

George Des

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Re: underdash a/c
« Reply #3 on: September 04, 2011, 13:01:03 »
Ray,

I only had some minor fitting problems with the SPAL unit I installed. The condensate tube on the back of the evaporator box needed to be relocated by soldering it to the underside of the box. I can not remember whether I used a Kuhlmeister or Fridgeking unit--they are basically the same but one or the other will not need to have this tube re-located. I also replaced the fan switch with a new 3 position switch and have had no problem with the various speed settings. I do recall I had to play around somewhat with the connections to the blower and switch to get it right. I did this before installing the unit into the car so it was easier to switch out the connections. You may also have the option of installing a rheostat type switch that will allow a full range of speeds.

George

Raymond

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Re: underdash a/c
« Reply #4 on: September 04, 2011, 13:28:18 »
Drilling the holes, cutting the plastic corner and putting an elbow on the drain tube would be what I consider "minor fitting problems".  I also replaced every bit of foam seal that I encountered.  In some cases the new material was a bit thicker than the original requiring some effort to compress it.  None of this was really daunting. 

The switch confused me.  It worked perfectly on the old blower.  The new blower had three speeds when bench tested.  So, that the two don't get along was a surprise.  My biggest complaint with the lack of low speed is that it gets too cold in the car.  I have a new condenser and the Sanden 508 compressor running R-12. ;D 

David, while I had the vent assembly off, I fabricated a baffle to direct more airflow from the passenger side over to the driver side.  It has helped reduce the effect of frozen passenger knees. 
Ray
'68 280SL 5-spd "California" Coupe

George Des

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Re: underdash a/c
« Reply #5 on: September 04, 2011, 14:23:25 »
Ray,

I think what you will find is that on the low speed it gets very cold especially if you run the a/c for a long period of time. I know this sounds odd, but the on the lower speed the air actually moves slower through the evaporator coil and it thus gets colder. Over time the interior will also get colder on the lower speeds. I'm running R-134A though mine on a Sanden 508 with a parallel flow condensor and it provides more than enough cooling when the hardtop is on and the windows rolled up. My engine temp bumps up slightly when running at idle for extended periods, but comes right back to normal at cruising speed. I find the SPAL blower much quieter and more powerful than the stock set-up.

1967 230SL Italian 5-Speed
George

davids

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Re: underdash a/c
« Reply #6 on: September 09, 2011, 13:59:27 »
THx ordered a spall blower .

chumps

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Re: underdash a/c
« Reply #7 on: February 12, 2013, 16:26:43 »
George, I am in the middle of upgrading my a/c. New compressor, new dryer, and new Spal blower. I replaced the condenser a couple of years ago. My question is - you said you replaced your 3 way switch with a new one. I was wondering where you got it and what kind it is. The wiring on the Spal and the wiring from the old switch don't look compatible to me. Just another quick question. Did you leave the small 'in bumper' condenser in the system? I know this is a thread that is a bit old, but it seemed a good place to ask my questions. Any info would help. Thanks, Chumps

George Des

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Re: underdash a/c
« Reply #8 on: February 13, 2013, 11:45:34 »
Chumps ,

I can not recall where I got my switch but you should be able to do a web search and find a number of switch suppliers who should be able to provide you with one that will work. As far as the condensors go, if you replace the main one in front of the radiator with a parallel flow one, you can remove the small one under the bumper

chumps

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Re: underdash a/c
« Reply #9 on: February 13, 2013, 15:07:47 »
Thanks for your information George. Chumps

RonB

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Re: underdash a/c & Heater Blower Motors
« Reply #10 on: February 11, 2014, 04:23:47 »
Re doing the a/c and blower motors with up grades. Has anyone been able to source out the numbers for both motors on internet?

Stay warm for those in cold the chilly cold.

Ron B
Previously FULL Member twice with over 500 post

71 280SL - SOLD on BAT
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Shvegel

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« Last Edit: February 18, 2014, 01:08:06 by Shvegel »