SAAC Forum

The Cars => 1969-1970 Shelby GT350/500 => Topic started by: Brian350 on August 26, 2026, 01:22:06 PM

Title: Air Cond shuts down randomly
Post by: Brian350 on August 26, 2026, 01:22:06 PM
Weird air cond issue in my 69 GT500 (Automatic) I'm driving around, air cond blasting (All major air cond components are brand new) then randomly the air just shuts off. Fan stops, dead, no noise or warning. I shut the fan off, drive a few minutes, and turn it back on and it works. Drive for a while and it quits, shut it off for a few and it works again.

Any ideas?

BTW, I love posting this stuff here, I've learned a lot from all of you who respond!
Title: Re: Air Cond shuts down randomly
Post by: crossboss on August 26, 2026, 02:41:59 PM
Kinda sounds like a relay is getting hot, and cuts the power. Some sort of an electrical issue. I'd check the switch with a voltage tester.
Title: Re: Air Cond shuts down randomly
Post by: Brian350 on August 27, 2026, 02:52:22 PM
Quote from: crossboss on August 26, 2026, 02:41:59 PMKinda sounds like a relay is getting hot, and cuts the power. Some sort of an electrical issue. I'd check the switch with a voltage tester.

Hey Vegas! Have I seen you around town at car events?

I'm a bit dense on this stuff, What switch should I test?
Title: Re: Air Cond shuts down randomly
Post by: crossboss on August 31, 2026, 12:16:12 AM
Quote from: Brian350 on August 27, 2026, 02:52:22 PM
Quote from: crossboss on August 26, 2026, 02:41:59 PMKinda sounds like a relay is getting hot, and cuts the power. Some sort of an electrical issue. I'd check the switch with a voltage tester.

Hey Vegas! Have I seen you around town at car events?

I'm a bit dense on this stuff, What switch should I test?
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Sometimes I go to the Cars n Coffee in Henderson off the 215. I would check all the switches/connections. Possibly a short/relay getting hot. Start with the basics. Also Google air conditioning cutting out...
Title: Re: Air Cond shuts down randomly
Post by: highland green on September 01, 2026, 10:20:14 AM
if its the fan that stops blowing. you need a new switch. the relay is part of the switch. if the air cond is not operating, the electric clutch on air compressor is faulty. my guess, try the switch first.
Title: Re: Air Cond shuts down randomly
Post by: Brian350 on September 03, 2026, 02:47:18 PM
Quote from: highland green on September 01, 2026, 10:20:14 AMif its the fan that stops blowing. you need a new switch. the relay is part of the switch. if the air cond is not operating, the electric clutch on air compressor is faulty. my guess, try the switch first.

Yeah, the AC blows nice and cold for a while then the fan shuts off, then a few minutes later I can turn it back on again. Compressor is new.
Title: Re: Air Cond shuts down randomly
Post by: KR Convertible on September 03, 2026, 02:55:10 PM
I have never had a 69/70 with a/c, so these are general guesses.

It could be as simple as crap in the cowl restricting air flow causing the fan to work harder. Could also be lack of lube on the blower motor bearings (bushings). After it cuts out, feel the blower motor to see how hot it is.
Title: Re: Air Cond shuts down randomly
Post by: Brian350 on September 03, 2026, 05:04:33 PM
Quote from: KR Convertible on September 03, 2026, 02:55:10 PMI have never had a 69/70 with a/c, so these are general guesses.

It could be as simple as crap in the cowl restricting air flow causing the fan to work harder. Could also be lack of lube on the blower motor bearings (bushings). After it cuts out, feel the blower motor to see how hot it is.

Thanks, I'll add this to my check list...
Title: Re: Air Cond shuts down randomly
Post by: Lincoln tech on September 03, 2026, 05:58:40 PM
The first thing I would do is while the fan is inop check ground and power at the fan , that can be done with a basic self powered test light. Just don't touch anything . If you get both and the fan doesn't work its the fan itself.
Title: Re: Air Cond shuts down randomly
Post by: Brian350 on September 03, 2026, 06:56:27 PM
Quote from: Lincoln tech on September 03, 2026, 05:58:40 PMThe first thing I would do is while the fan is inop check ground and power at the fan , that can be done with a basic self powered test light. Just don't touch anything . If you get both and the fan doesn't work its the fan itself.

Added to check list...thanks...