Kerry's '73 Restoration - Part Sixteen

Imperial Home Page -> Imperials by Year -> 1973 -> Kerry's Restoration -> Part 16


Interesting developments today on my 73. Decided to pull the front seats so I could get under the dash better. (I'm 6'3"). Pulling the seats was easy but they are heavy. Once they were out of the way it was much easier to stick my head under the dash and see what the heck was there. 

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First thing was to pull all the AC duct which are mainly held on my a single screw. Then I pulled 4 screws from the panel below the steering column. I noticed that when I MANUALLY moved the turn signal lever, there was sometimes a single "click" from the blinker. From this click I determined the approximate location of the flasher but still could not see it or feel it. Finally, after about 30 minutes I see a bright yellow round flasher with a tab on the end pressed into a flange WAY up under the dash. Never could get my hand on it but was able to push the tab out with a screwdriver and then it fell to a reachable location. Plugging in a standard flasher my signals now work great. I can promise you that it will be located in a more accessible place when I put the dash back together. This is one time when Mother Mopar screwed up. Thing is, there is plenty of room up by the fuse panel without hiding it behind 15 other things.

I decided that I want to get AC working NOW. I did the R134 conversion last week but did not get cold air. I'll worry about the Autotemp II later, maybe. I assume that the two toggle switches control the fan and the AC clutch. First the clutch. A wire was not connected and when it was, the clutch engaged. 

Now to the fan, the air volume seems very low. Hot wiring the fan directly to 12V does not change the volume so what I have is what I have. The question is, are there valves or doors that are not being opened. Or do the Imps just have low air volume?

Starting the car and turning on the AC results in frost on the expansion valve going into the evaporator (inside the car) and ambient temp on the hose coming out. This means (I think) that there is pretty cold stuff in there somewhere but you sure can't feel it. No water is going into the heater core so that is not overriding the cold air from the AC. Seems to me the only thing to do is pull the heater core and get to all the stuff that directs air. The motor was hot so I'll pull what I can today and tomorrow I'll take the hoses off and drain the cooling system to get the heater core out. The condenser is right in back of it and when I can lay my hand on it, I will be able to determine how cold it is getting and decide if my problem is blockage or what. I'll also try and figure out what all the Autotemp II stuff does. Having the parts car should help because it has not been altered as far as I can tell.

Wednesday 8/28

Finally got the AC working on the 73. This may get somewhat technical and I'm talking about stuff that I'm NOT really that strong on so take this with a grain of salt.

This am, I pulled the heater core and actually laid eyes on my evaporator. 

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Here were the symptoms. Line (liquid line) leaving drier was cold and sweating, Expansion valve was frosted. Evaporator was frosted over near the expansion valve and cold to the touch. Low side gauge read -30 inches of mercury and the high side was 250+. No cold air. My car wizard neighbor told me the new drier or expansion valve was blocked. The gauge readings indicate a blockage somewhere. Normal low side reading is +30. Remember the compressor is just a pump. In this case it was trying to pump against a near complete blockage.

When I broke the fittings on the expansion valve, some black "gunk" came out, same with the drier. I blew air through the hard line and drier. Some foam came out of the drier. Just to be sure, I blew air through the evaporator. There appears to be some resistance but since there are a lot of capillary tubes, I expect that is normal.

Putting everything back together and pulling a vacuum, it was time to charge. This time it worked like a charm. Low side reading is 20 degrees (a little too cold) and pressure is 30 psi. High side is 200. Liquid line from drier does not sweat but the line from the evaporator to the compressor sweats all the way to the compressor.

A thermometer sitting in the glove box opening (remember the entire front of the AC unit is out) reads 40 degree air. Still not a lot of volume but Elijah tells me that this series was very under powered from the fan standpoint. 

I think this will do the job nicely. Now I just have to rig up some controls for the various vents so I can get air out the vents and heat out the floor. I am not going to try and get the Autotemp working at this time. I want to drive her this year! Since it has already been bypassed, I will complete the job. I would LOVE to find a heat/ac control system from a non-Autotemp IMP or Chrysler. Trade some parts???

Thursday 8/31

Still messing with the AC.  I REALLY do not like the air flow, or better said, lack thereof.  Way back, I pulled the inner fender panels and the blower motor (and power antenna) is easily accessible. 

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The above photo, which is washed out by the flash, shows the blower motor at the end of the red arrow.  The vertical line is the power antenna.  Strangely enough, the motor looks very similar to the ones in my Chevy pickups.  Humm.  The Chevy's have plenty of air flow.  Humm.

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The above shot shows the Chevy blower motor.  They look just alike.  Since the new parts car has a motor, I can afford to waste one.  Both cars have only a few 5/16 bolts holding them in.  Chevy pickups are very common and I can get a used motor for probably 5 bucks.  I THINK I can adapt it pretty easy.  It's very hot and humid in Alabama.  If I'm going to have an Imperial as a daily driver, I'm dang sure going to have AC that will freeze the thingies off a polar bear.  I'll look into it next week.  This weekend I'm doing non Imperial projects while the family is off from work.

Next Chapter...

Kerry's '73 Restoration Saga Main...

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