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Old 10-12-2019, 04:43 PM   #1
Sheepdip
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Calling all Electrical Guru's

Have been refurbishing my HVAC system as of lately, got all the interior components completed when an electrical problem popped up.

All the fan settings worked great on heat but as soon as I swapped it to A/C it would instantly blow the 25A fuse. Long story short an electrical diagram, an ohm meter and a few cuss words the problem was found, it was this little diode at the compressor plug-in had failed sending it to ground as soon as the compressor switch inside that's A/C cable actuated was activated.

I know originally these were to prevent voltage spikes when the compressor clutch was deactivated. My new compressor is a Old Air (Sanden) re-production of the original configuration to fit original brackets and has 2 wires like the original +/-.

My question is: Can I eliminate the diode or is it still needed. They make new pigtails with and without the diode. Might be a question for Sanden.
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Old 10-12-2019, 04:52 PM   #2
kwmech
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Re: Calling all Electrical Guru's

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Originally Posted by Sheepdip View Post
.

I know originally these were to prevent voltage spikes when the compressor clutch was deactivated. My new compressor is a Old Air (Sanden) re-production of the original configuration to fit original brackets and has 2 wires like the original +/-.

My question is: Can I eliminate the diode or is it still needed. They make new pigtails with and without the diode. Might be a question for Sanden.
The diode actually was to keep the engine from running when you shut the key off when the AC was still engaged. So yes, I would keep it.
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Old 10-12-2019, 05:32 PM   #3
Sheepdip
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Re: Calling all Electrical Guru's

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Originally Posted by kwmech View Post
The diode actually was to keep the engine from running when you shut the key off when the AC was still engaged. So yes, I would keep it.
Ahhh...Ok... crafty those electrical engineers. New one with diode ordered.

Thank You!

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