A/C inop - compressor clutch is bad?

WAYWARDSON

MEMBER
1998 LINCOLN CONTINENTAL
V8
FWD
AUTOMATIC
130,000 MILES

This is my mother's car. The a/c stopped working. Suspected it might need an R134 charge, so I picked some up. When I opened the hood, I heard a clicking noise at approximately 5 second intervals coming from the air compressor. On a hunch, I hooked up a gauge to the valve. After a click, the pressure would go to the normal range. After the next click, the pressure would drop to the low range. I watched it do this for 5 or 6 cycles.

Does this mean the compressor clutch is bad? Or could it be the climate control processor sending bad signals, cycling the compressor clutch on and off? How do I check?

1 Reply

KASEKENNY

MECHANIC
18,907 POSTS

I suspect you are using the gauge on the can to show that it is low when the compressor clicks on.

If this is the case, then I would add freon until it is in the normal range when the compressor is on.

Basically, when the compressor comes on it will create the pressure difference in the low and high side and if the freon is low, this is when it will show up. If it is extremely low, then it will show low all the time.

https://www.2carpros.com/articles/air-conditioner-how-to-add-freon

The best way to check this is to use a gauge set and check both sides of the system when this is acting up. That will tell us what the issue is.

https://www.2carpros.com/articles/re-charge-an-air-conditioner-system

I am attaching a chart below that will help with this based on pressures.

Let me know if you have questions.

Thanks

Image (Click to make bigger)