Test AC Clutch / Compressor
- Thread starter mjonesjr84
- Start date
No clue what I did, but it works as it is supposed to now with the relay installed. It's blowing ice.
IOwnCalculus
TJ Enthusiast
Probably had a poor connection at the relay itself. The clutch needs a decent hit of power to actually pull in. I went chasing down a similar rabbit hole on my WJ. On that I'd confirmed 12V at the compressor with a digital meter, but I hadn't checked with a real load, and thus wasted time and money replacing the clutch/compressor when the real root cause was a poor connection upstream.
When I did finally verify that, I discovered that with a real load the 12V I was seeing at the compressor would drop to zero with anything more than a digital meter on it. Found a loose mid-harness connector, cleaned and reseated it, and it worked perfectly from then on. If swapping relays did this then that was probably where your loose/dirty connection was.
When I did finally verify that, I discovered that with a real load the 12V I was seeing at the compressor would drop to zero with anything more than a digital meter on it. Found a loose mid-harness connector, cleaned and reseated it, and it worked perfectly from then on. If swapping relays did this then that was probably where your loose/dirty connection was.
I have seen relays that have continuity read across the relays contacts, but will not hold when a load is placed on the magnetic coil inside the relay.
Then there can be oxidation problems with the female receptacle where the relay plugs into which cause the relay to not engage or stay engaged.
The fact that your relay stays engaged now can be a indication of dirty (oxidized) copper relay terminal connections; after the removal and reinsertion several times has scraped the terminal connections to allow electricity to flow.
I'm considering picking up a new relay for the AC. I'm going out on a limb that every relay is the factory installed ones.
Before spending the money on the relays; you should examine and clean the relays receptacles and terminals to ensure a good electrical connection.
I purchased a '93 Toyota LandCruiser 3.5L 5 cyl diesel overseas and had to go over all the fuses, power connections and grounds, and still have problems periodically with oxidized connections due to the humidity affect on copper connections.
Everything looks good as far as cleanliness on the terminals. I wouldn't be surprised if the relay was just weak.
In hindsight, the AC not working is why I got the TJ as cheap as I did.
In hindsight, the AC not working is why I got the TJ as cheap as I did.
You can measure the resistance on the magnetic coil windings of the relay; my experience is if... the connection reads more than 80 ohms the resistance can be too much with electricity applied to the circuit causing the resistance to increase and the coil to drop out due to overheating.
Relay contact could have been bad or dirty . Run it see how it acts.
My buddy paid next to nothing for a nice explorer, had a blown fuse for the transmission
I did that to a 98 GC 5.9 Limited. It wouldn't drive. Come to find out it had a busted transmission cooler hose and was out of fluid.
I got my TJ for $3k. The AC was one reason and the transmission grinding into 2nd was the other. After changing transmission fluid, the grinding went away too.
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