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A/C Control Head - Relay

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Old Sep 2, 2024 | 03:34 PM
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Default A/C Control Head - Relay

Unfortunately I do not have a great understanding of electronics and how to read all the numbers on a Relay - Im just about to tackle my A/C control head and wanted to see if you guys can confirm if this Relay will work for the rebuild. If not does anyone now where to get a relay that will work ?




Last edited by giddyupp; Sep 2, 2024 at 03:35 PM.
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Old Sep 2, 2024 | 04:45 PM
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Yes, that will work. Don't forget to put a 4amp fuse at the freeze switch.
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Old Sep 2, 2024 | 05:13 PM
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Originally Posted by Kevin in Atlanta
Yes, that will work. Don't forget to put a 4amp fuse at the freeze switch.
Great thanks - for the 4amp fuse - does it matter if it goes before or after the Freeze switch ?
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Old Sep 2, 2024 | 05:49 PM
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Originally Posted by giddyupp
Great thanks - for the 4amp fuse - does it matter if it goes before or after the Freeze switch ?
I don't think so. I never really given it that much thought.
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Old Sep 2, 2024 | 09:28 PM
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I believe 'worf928' (no longer on this forum) always recommended the 4 amp fuse AFTER the freeze switch, on the circuit that goes to the compressor.

Last edited by Gary Knox; Sep 2, 2024 at 09:30 PM.
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Old Sep 3, 2024 | 01:20 PM
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Thanks for the help guys - I got this all installed. My soldering skills were not the best but did a bunch of practicing before I dove in. I followed Dwaynes write up and my A/C controller now works great. I went with the 3amp fuse before the freeze switch and so far it seems to be working fine. $12.70 and maybe 1 hour of my time instead of $400 for a refurbished unit. Very happy !!
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Old Sep 3, 2024 | 05:43 PM
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Originally Posted by Gary Knox
I believe 'worf928' (no longer on this forum) always recommended the 4 amp fuse AFTER the freeze switch, on the circuit that goes to the compressor.
I did and still do. I don’t know that it matters if it is electrically before or after the anti-freeze switch. So, I describe it as “at” the anti-freeze switch because that location results in a simple and concealed location.

4 AMP because the compressor takes 3.0 +/- 0.050-ish AMPs. If I could get a 3.1 AMP fuse that’s what I’d use.


With respect to the preamble: I’m like Beetlejuice.
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Old Sep 3, 2024 | 05:44 PM
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Originally Posted by giddyupp
I went with the 3amp fuse before the freeze switch!
Carry spares.
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congratulations!
Originally Posted by giddyupp
instead of $400 for a refurbished unit. Very happy !!
Is that all they cost?
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Old Sep 4, 2024 | 11:26 AM
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My suggestion is to pop the cover off the onboard relay and try to clean the contacts with some 800-1200 grit paper, then see if it'll drive an outboard relay before outboarding it with a bundle of wires. If the failure mode is due to too-much current for the tiny relay the contacts should IMO come back to life well enough to run a relay (under 250ma). I have a control head I believe is good other than the plastic selector "clicker" being broken, I might take a closer look at it to see how feasible this is.
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