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post #1 of 7 (permalink) Old 04-27-2019, 04:22 PM Thread Starter
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AC Pressure Switch

Looking for some AC advice: have a 2011 Terrain 2.4 with basic cabin temp control. The AC does not work, and the radiator blower has yet to come on under normal driving conditions (granted, its still cool here in NH). All the interior cabin ventilation stuff works, heat, blend door, blower. What I've done:

- Tested the radiator fan by jumping 12V to the output relay terminal, fan spun up both high and low speed relays.
- tested the AC compressor clutch by jumping 12 to the output side of the comp relay, clicked on (engine was off)
- tested all above relays outside of the fuse box. coils click in, 0 ohms across the contacts.
-tested all fuses ok
-
So a few questions:

- Should the radiator fan come on under normal cool temps? The temp gauge never goes above the 3rd line (just left of straight down).
- I disconnected the connector to the AC high side pressure switch (smaller tube), and the radiator fan started running. Engine was running and otherwise not very hot. Does this make sense?
- Have not connected to AC gauges, since I dont have a set. Based on the above, is it time to invest in some?

Thanks in advance!


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post #2 of 7 (permalink) Old 04-27-2019, 10:44 PM
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Time for some AC gauges. If system is low on 134 it will not start compressor or fans. It's a compressor protection feature. It takes a lot of idle to get fans to come on in cool temps. Fans will not start when driving in cool temps as plenty of airflow when in motion.

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post #3 of 7 (permalink) Old 04-28-2019, 11:46 AM
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Quote:
Originally Posted by repairman54 View Post
Time for some AC gauges. If system is low on 134 it will not start compressor or fans. It's a compressor protection feature. It takes a lot of idle to get fans to come on in cool temps. Fans will not start when driving in cool temps as plenty of airflow when in motion.
Good info from repairman54.
If you suspect a bad AC Pressure Switch unplug it and jump the two pins in the connector.
This is usually done when charging, depending on how much 134 you are adding and your method of charging.

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post #4 of 7 (permalink) Old 04-28-2019, 02:21 PM Thread Starter
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Thanks repairman54 and rednox301! Good feedback and advice, I think the path forward just got a bit clearer...will post back an update. Unfortunately, I'm strictly a weekend warrior on this, gotta pay the bills!

Cheers!

Go C's and B's!


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post #5 of 7 (permalink) Old 05-07-2019, 08:14 PM Thread Starter
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Well, Not looking good for the C's, B's still in the fight! No new news on the AC problem, but did change the Diff & Xfer fluids. They really didn't look that bad at 84000 miles, assuming its the first change. Could be a testament to the synth fluid. There was a good amount of metal flake in it, though, and some really gritty chunks in the bottom of the pan after pouring it out....


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post #6 of 7 (permalink) Old 05-07-2019, 09:21 PM
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Probably a good move changing those fluids. Lots of powdered/pressed metal gears in use these days. Last a long time but the face surfaces will spall/flake off and that's not good for bearings, bushings, and seals. Sure could be from something else though.
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post #7 of 7 (permalink) Old 05-08-2019, 08:30 PM Thread Starter
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Roger that, tom3, not to mention those flakes & chunks wearing on the gears themselves. Hope it adds a few miles, since its in pretty good shape otherwise. Still gotta do a drain and fill on the tranny. Got some questions to post on one of those threads...

Cheers!


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