relay issue/confusion
September 18th, 2013, 05:07 PM
#1
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relay issue/confusion
the a/c in my '73 88 will only operate on HIGH. i think i need a low range relay. got assistance at cadillac dealer. he gave me the part number 409560 which is a low range relay. upon finding a new one, the one on my car doesn't match. of course, this has stumped me. i'm going to post here a shot of my relay & a 409560. not sure what you call the prongs, but they are not the same. anybody have any ideas? thanks!!
September 18th, 2013, 06:24 PM
#2
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Location: The Hudson Valley
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I think we need to know a little bit more about your problem.
You're saying that your fan operates on High only, but not on any of the three lower speeds?
That will have nothing to do with your low-speed relay, so the Caddy dealer doesn't know what he's talking about.
You may need to do a little diagnosis, but the first thing I would suspect would be your resistor block, which is screwed into your air duct under the hood.
If you take it out and the connection is broken in the coils, then it's a no-brainer.
If not, then you'll have to check and see if you've got voltage coming in to it from the switch, and if you've got continuity between the terminals.
- Eric
You're saying that your fan operates on High only, but not on any of the three lower speeds?
That will have nothing to do with your low-speed relay, so the Caddy dealer doesn't know what he's talking about.
You may need to do a little diagnosis, but the first thing I would suspect would be your resistor block, which is screwed into your air duct under the hood.
If you take it out and the connection is broken in the coils, then it's a no-brainer.
If not, then you'll have to check and see if you've got voltage coming in to it from the switch, and if you've got continuity between the terminals.
- Eric
September 18th, 2013, 07:59 PM
#3
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Location: Southeast Michigan
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I agree with Eric on it most likely being the resistor. Your blower switch on High is wired directly to the blower fan, Medium and Low run through the resistor.
7398HeaterWiringDiagram_zps958ee82a.jpg
7398HeaterWiringDiagram_zps958ee82a.jpg
September 19th, 2013, 07:06 PM
#6
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THANKS! i so appreciate the help. well, we can't really blame the caddy parts guy. we can blame me. i've been trying to figure out why when i move the lever to A/C, it automatically goes to high cool & the fan switch won't effect it. the heater & fan do work okay & respond to the fan switch's selection. anyway, i somehow thought i'd figured out that it was the relay & pointed to it & asked the tech what the number was to that part. i did tell him the trouble & he didn't disagree. SO, now i'll have to figure out what air duct you're speaking of. as you may be able to tell, i'm trying not to bring the car to a mechanic. and mdchanic...is your '73 really that pink?
September 20th, 2013, 03:14 AM
#7
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In that case, the resistor block is not your problem.
Maybe it would be helpful if you were to describe your problem exactly.
And describe the car, and the type of A/C exactly. You don't have Comfortron, do you?
- Eric
September 20th, 2013, 06:48 AM
#9
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like i said, heater, vent, defrost...they all operate correctly & the fan works properly as well. it is only when the lever is moved to a/c, then the fan automatically goes to high and moving the fan switch does nothing. it does not matter where the fan switch is seated either. i do NOT have comfortron. it is the basic a/c. the car has the 350. can't think of another detail that might help.
September 20th, 2013, 06:55 AM
#10
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like i said, heater, vent, defrost...they all operate correctly & the fan works properly as well. it is only when the lever is moved to a/c, then the fan automatically goes to high and moving the fan switch does nothing. it does not matter where the fan switch is seated either. i do NOT have comfortron. it is the basic a/c. the car has the 350. can't think of another detail that might help.
MOVE THE TEMP LEVER TO the right 1/2 inch!
September 20th, 2013, 08:13 AM
#11
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I don't recall exactly how the Cutlass works, but the Chebbies of the same period will switch the fan to High when set to Max A/C, as well as closing the recirc door and the heat valve.
Sounds like normal operation to me, perhaps needing a bit of an adjustment.
Have you read the owner's manual?
- Eric
Sounds like normal operation to me, perhaps needing a bit of an adjustment.
Have you read the owner's manual?
- Eric
September 20th, 2013, 06:41 PM
#12
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alant: i've moved and tried everything, but thanks for the suggestion!
eric: this is on regular a/c, not max. i may not be a genius or a mechanic, but i'm not a boob. again, thanks for the suggestions!
eric: this is on regular a/c, not max. i may not be a genius or a mechanic, but i'm not a boob. again, thanks for the suggestions!
September 21st, 2013, 02:29 AM
#13
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I took out my manual and it does say there's a noticeable click from cold to a 1/2" to the right that sets the fan speed and vent flaps from max to norm. So perhaps yours is stuck there. if you get fan control under all other settings then one would assume there's your problem. And NO your NOT a BOOB! this is one of those quirky things that we are all here to help with in anyway we can. I love my online forums and have prob 20 of them!
September 27th, 2013, 06:21 PM
#21
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