I posted about a "pulsing" problem while idling in my truck. As someone suggested I checked the alternator by disconnecting the battery with the engine running and accelerating a bit (with the car stopped, in "park" and e-brake engaged). Anyway, the truck ran fine and the alt needle went to the "charge" side of the gauge and stayed there. It actually did much better than with the battery connected.
When I went to reconnect the battery, I noticed a strange clicking noise while the engine was running. I connected the battery and saw that the AC compressor was cycling off and on when the click sound happened. The AC was turned on in the cab. Also, the compressor makes some strange noise when engaged. I took a short video of it.


I also took a video with the AC turned off. to show the difference. It runs much more smoothly of course. I'll take it out and see if the idling problems still occur. (please ignore the ice cream truck music)


BTW, I've been having issues with the AC not working too well. Lately it's gotten much worse and it barely blows cooler than the ambient temp.

Any input from those who know?

Thanks

 

You're lucky you didn't fry the alternator. It wouldn't surprise me if it went out soon. You're not supposed to disconnect the battery with the truck running. A/C might need a charge.

 

Well, I had asked a friend who's a mechanic and has been making a living for years repairing cars. He suggested doing that to test the alternator. I thought he might be knowledgeable about these things...

I am taking the truck to a shop tomorrow to have the AC checked for leaks. I guess there is also the possibility that the switch which controls the clutch might be going bad..

 

You used to be able to test them like that, but not anymore. Your friend needs to get with the times.

 

That is the classic sign of a A/C system low on freon. Have it checked for leaks and then recharged.

 

I agree with all said above.....even though I'm not "with the times" I still tend to disconnect batteries on occasion. Anyways, sounds like low freon.....the "pulsing" idle is just the computer compensating for an increased lowed on the engine.....it's completely normal. Like already said, have your ac system checked.

 

hello from the video I would sugest that the A.C is low on refigerant have it leak tested & recharged.The A.C. should cut in & out about every 30 seconds even when not switched on this is a design issue to keep oil circulating during non use.

 

It's only been a year and a half. I hope it's fixed by now.