A/C, idling, and battery issue
07-14-2016, 06:57 PM
#1
3rd Gear
Thread Starter
A/C, idling, and battery issue
My 1999 C2 is having some A/C, idling, and battery issues.
Over the course of a few weeks of normal daily driving, the battery slowing loses power until it can no longer crank.
The A/C blows kinda-sorta cold for a while (I'm in South Florida, so if it's not blowing hot air it must be doing something).
When I turn on the A/C there's a noticeable drop in battery power (see the gauge in the video below). Then the RPMs jump a bit and gradually start dropping below where they started, almost to the point of stalling. Each drop is accompanied by a clicking sound from the engine compartment. After I cut off the A/C, it still idles low.
I think some videos may help with this description.
Dash:
Engine compartment:
The first part is idling with no A/C, then you can hear it when I turn on the A/C. At no point am I touching the throttle - all those RPM changes are being caused (I think) by the A/C. The second video of the engine compartment with the A/C running so you can hear the clicking noise a little better.
The A/C was replaced a few months ago and worked well for a little while. I've also recharged and checked that the battery holds a charge when it's not hooked up. I've monitored the power draw when it is hooked up with the car off, which seems to be normal.
Any ideas?
Over the course of a few weeks of normal daily driving, the battery slowing loses power until it can no longer crank.
The A/C blows kinda-sorta cold for a while (I'm in South Florida, so if it's not blowing hot air it must be doing something).
When I turn on the A/C there's a noticeable drop in battery power (see the gauge in the video below). Then the RPMs jump a bit and gradually start dropping below where they started, almost to the point of stalling. Each drop is accompanied by a clicking sound from the engine compartment. After I cut off the A/C, it still idles low.
I think some videos may help with this description.
Dash:
Engine compartment:
The first part is idling with no A/C, then you can hear it when I turn on the A/C. At no point am I touching the throttle - all those RPM changes are being caused (I think) by the A/C. The second video of the engine compartment with the A/C running so you can hear the clicking noise a little better.
The A/C was replaced a few months ago and worked well for a little while. I've also recharged and checked that the battery holds a charge when it's not hooked up. I've monitored the power draw when it is hooked up with the car off, which seems to be normal.
Any ideas?
07-14-2016, 10:22 PM
#2
Sounds like the a/c compressor clutch is cycling, which is not normal as our a/c compressor has variable displacement and the clutch should engage and keep engaged as long as the a/c is ON. There are two pressure switches (low and high) that can cut power to the clutch. I wonder if your system is low in refrigerant. I think your best bet is to take it back to the shop that worked on it. The a/c clearly has problems.
Your voltmeter reading is on the low side (if it's accurate). You need at least 13.5v to charge the battery. At cold start, you should see about 14v and then it should be between 13.5v and 14.5v whenever the engine is running, with or without electrical loads. You may want to bring your battery to an auto parts store for load testing.
Your voltmeter reading is on the low side (if it's accurate). You need at least 13.5v to charge the battery. At cold start, you should see about 14v and then it should be between 13.5v and 14.5v whenever the engine is running, with or without electrical loads. You may want to bring your battery to an auto parts store for load testing.
07-16-2016, 07:16 PM
#4
3rd Gear
Thread Starter
I picked up an A/C recharge kit to check the refrigerant. Turns out it was way too full (WTF?). Almost 80+ PSI.
Getting that back to normal fixed the A/C and the idling issues. I'm now recharging the battery before digging further.
---
Pro tip: Be careful when bleeding the A/C. You may accidentally jam the valve and cover your garage in refrigerant. If that happens, unscrew the valve and pop the spring back in place. Then clean your garage.
Getting that back to normal fixed the A/C and the idling issues. I'm now recharging the battery before digging further.
---
Pro tip: Be careful when bleeding the A/C. You may accidentally jam the valve and cover your garage in refrigerant. If that happens, unscrew the valve and pop the spring back in place. Then clean your garage.
