I removed the relay and bypassed the relay with a jumper wire, added coolant with the wire on, compressor sucked some in but within a minute the clutch got super hot, had to turn off engine. Very strong clutch burning smell. Now the "bypass trick" don't work, clutch just gets hot & smelly. Any hope the clutch may work with a garage charge? Better to put new compressor than repair clutch (if needed). Was I supposed to immediately remove the jumper once the clutch starts? Last year the clutch wouldn't turn on to suck in the coolant, a garage drained added & coolant everything worked fine all summer. A very slow leak through the winter. I have a 2003 4runner. Please help, very frustrated.

  • 1
    Welcome to Motor Vehicle Maintenance & Repair! It's pretty easy to add too much or too little coolant -- did you put the system under vacuum before adding coolant? And how did you decide how much coolant to put in? By weight? Till it felt right?
    – Cullub
    Jun 9 '19 at 19:37
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    Every spring for several years just added a small can of Duracool on my 92 4R. Pressure is at 85 psi (red zone) & I think it was already in red zone prior to my adding attempt. It was blowing hot. Previously the pressure would go up then settle down as the engine kept running. I'm assuming it's the clutch that's overheating within seconds (it's hot) or could it be the compressor itself? Thanks for the welcome, much appreciated!
    – user1988
    Jun 9 '19 at 22:54
  • It could be either, and putting too much refrigerant into the system could cause the clutch to go too. What is a "garage charge" from your post?
    – Cullub
    Jun 10 '19 at 2:45
  • Actually, reading that again, I'm guessing that that's taking it to a mechanic for them to fill it up. They do it similarly to the way I show in the link in my answer below, so you can take a look at that. (I'm in north central US, and here a garage is where you park your car overnight. We talk about taking your car in to the "Shop" for an oil change.)
    – Cullub
    Jun 10 '19 at 2:56
  • To me, that sounds like your compressor seized. Grab the clutch hub with your hands (engine off and keys in your pocket obviously) and try to spin it around. Does it spin easily with a slight uniform resistance across one whole turn? You weren't supposed to charge the system that way from the start. It's very hard on the compressor. While it's running with low refrigerant, less lubricant is flowing through it than with a full refrigerant charge inside.
    – Al_
    Jun 11 '19 at 19:18

To me, this sounds like your clutch, which is lucky because that's a (pretty) easy thing to replace (you don't generally have to replace the compressor at the same time, and therefore won't have to drain the system). That said, your entire setup does sound pretty hacky, and I'd suggest fixing it the right way.

First, having a jumper for the system should not be needed. The point of the electronics is to turn off the compressor if the system is in an unsafe state. If there's not enough refrigerant, it'll turn itself off to protect the compressor from getting dry. If there's too much refrigerant, it'll turn itself off to protect the clutch from trying too hard. And if it's too cold, it'll turn the clutch off to protect the evaporator from freezing.

Here's my guide on recharging A/C systems, which might be worth a read, even though it looks like you're already familiar with a lot of this. If you have to add refrigerant that often (once a year), you definitely have a leak. If you'd just like to replace the clutch and see if things work themselves out, that might fix your problem for now, but generally old O-Rings are your problem. The connection between the compressor and the pipes generally has one of the few o-rings your A/C system uses, and it's a common culprit. After 5-10 years, those can start getting old, and by 10-15 years, it's good to replace them. You do have to drain the system to do that though.

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