4 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHA/C, idling, and battery issue
Leading reported evidence
Replace a/c
Performed · outcome unconfirmed
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
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Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Performed · outcome unconfirmed · Original poster
The A/C was replaced a few months ago and worked well for a little while.
Leading evidence: 'Replace a/c' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Check refrigerant' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
Source reports, not a diagnosis or a success probability. Counts refer to discussions and can overlap.
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Discussions that contain suggestions
1
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Suggestion · Original poster
I picked up an A/C recharge kit to check the refrigerant.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
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0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion · Original poster
At no point am I touching the throttle - all those RPM changes are being caused (I think) by the A/C.
Counts describe captured discussions, not unique people or a diagnosis. Author identities are not reliably stored. Exact duplicate evidence is counted once across matching discussions; one discussion counts at most once per action/state. Multiple repairs reported together remain a combination. Suggestions and failed attempts do not establish a fix. Matches cover whole discussions and can include related faults, model variants and incomplete threads.
4 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
Rennlist: 1 discussions
0 evidence records excluded for query context · 0 excluded by outcome qualification · 0 adjusted by outcome qualification.
2 acknowledgements have no verified action link; they do not establish a repair result.
Outcome without a verified action link
I think your best bet is to take it back to the shop that worked on it.
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:
996 Dash - YouTube
Engine compartment:
996 Engine Compartment - YouTube
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?
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.
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.
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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.
This is a source reference. Confirm exact model applicability in the original material.
