AC woes continue on 67 Riv

[rocky5517]

I tightened the belt once, no good. Tightened it a second time, it caught, but sporadically. Tightened it a third time and it worked but was a little noisy, like a bearing. But it worked. Until this morning. My question is, would I damage anything it I ran a jumper straight from the battery to the AC clutch, and grounded it properly? This would hopefully eliminate the fan switch as a problem, although it is working on all speeds.

  

[rocky5517]

Follow up question; I see evidence of some freon leak/ would low freon knock out the compressor or prevent the clutch from engaging?

[1965rivgs]

Hi Rocky.

  Sending 12 volts unprotected shouldnt bother the clutch unless there is a short in which case I`m sure there would be smoke or heat. Why not use a test light?

  The AC compressor should engage without regard to the refrigerant level in an old car such as yours. Getting into the `70`s was a different story but not in the mid to late `60`s.

  It is rather common for both the pulley bearing to fail as well as the clutch to become "weak" in this model compressor. You could be facing one or the other or a combo of both, assuming your electrical connections are proper including a good ground.

Tom Mooney

 

Edited August 2, 2018 by 1965rivgs (see edit history)

[JZRIV]

Have you determined the clutch is engaging and staying engaged for certain? This is very important so you aren't chasing wrong cause. jumping direct 12V to clutch will eliminate possible wiring issue causing low or no voltage.

 

If the clutch bearing is failing you will hear it even when the clutch is not engaged because it spins all the time.

 

Make sure you have the RIGHT belt with correct pitch/angle so it seats with full contact in the pulleys. Sometimes a belt and pulley can get glazed on the surface. Especially if its been slipping awhile. If suspect, get a new belt, or get a can of belt dressing and apply to belt.....though that's not solving root cause, it will stop a slipping belt for awhile.

[rocky5517]

Thanks guys; am bringing it to mechanic's home tonight.  Will keep you posted. I don't hear the clutch bearing unless it's engaged. I can spin it by hand fairly easily.

[rocky5517]

I jumped the clutch and it seems to be working fine. It snaps in and out. Now for some more R-12.

[1965rivgs]

Rocky,

  If you jumped the clutch and all seems fine there must be an issue with the switch or associated wiring responsible for directing voltage to the clutch when calling for AC...or you have a ground issue

Tom

[rocky5517]

Problem solved. All it needed was a charge of Freon. The switch that senses the pressure shut down the compressor. We jumped it, it engaged, and it took a few lbs of Freon. The noise from the compressor went away as soon as the Fren filled up. But the valve (POA?) wasn't making good connection so he put new connectors on it, taped them up, and off we went. Thanks to all.

[1965rivgs]

Rocky,

  Very, very surprised the `67 system has a pressure switch which interrupts the compressor clutch circuit?!?!  Has your system been modified with some sort of a clutch cycling arrangement?

  Can anyone familiar with the `67 system comment? Or maybe I need to take a look at a `67 schematic...dont recall encountering such a pressure switch until well into the `70`s??

Tom

[1965rivgs]

Took the initiative to check the `67 shop manual heat/AC circuit schematic, see below. According to the original wiring arrangement there is no pressure controlled switch which interrupts the AC compressor clutch circuit. The only switch present should be the AC control switch which is part of the control panel with the slide levers...and this is a mechanical switch not incorporated into the refrigeration system.

Either your system has been modified (which is implied based on your reference to the connections at the POA valve ??) or it is coincidence that your problem has disappeared.

  Tom

 

 

Edited August 7, 2018 by 1965rivgs (see edit history)

[rocky5517]

We installed a "POA UPGRADE" or something similiar from the guys at Cold Air about 5 years ago.. Not sure why but it obviously works. Interesting that when we jumped the switch to allow the freon to enter the system, the clutch was noisy but quieted down after a minute.  Mechanic did the "squeeze test" on the wiring because the clutch was still engaging in and out. Seemed the connections on the POA valve were a little dirty. When he isolated the problem , by squeezing the wires at the POA valve, clutch went on and off. New connnections, taped up, and away we went.Apparently a simple system; when the pressure drops, the continuity breaks at the switch and disengages the clutch. Didn't take much for it to work properly. Seems to be a good idea, to protect your system from damage if you run out of freon, I guess. System is running on R-12.

[rocky5517]

Follow up; as you can see from the pix, the upgraded system has a black "boot"with green wires that clip onto the switch. As most of you know, when the switch is open(?) the clutch is dis-engaged.If the system shuts down no freon can be pumped in until you jump the two connectors, which then closes the switch and engages the clutch and opens things up. If you have one of these upgrades and are having trouble with your system, pop the black boot off, check the connections and make sure they're good and tight. Apologies for the primitive descriptions herein. And God bless the wrench spinners of the world.