XJnDixie
NAXJA Forum User
- Location
- Alabaster, Alabama
'90 XJ Limited 4.0
Well I noticed yesterday that my ammeter drops drastically when I switch over to defroster.... I could hear the a/c kick on, and I understand why it does, but the voltage drop seems drastic to me because I have a low idle problem....and that may be my whole problem is the low idle (possibly in need of a TPS adjustment).....Ammeter at idle is usually around 14V - when I switch to defroster the compressor kicks on and voltage drops to roughly 11v - almost in the red..... Idle is around 300 (low huh?) but jumps up to around 750 when the compressor cycles on.....and my lights dim as in the post below....
Would bumping up the throttle stop adjustment screw help any?
Anyway - I did a search and found this thread and since there was no follow-up, I was wondering if anyone had done this - and if it caused any problems??
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Crown 01-13-2005 10:14
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Defroster / A/C question
Hi all,
Evidently, when the defroster is on, it also cycles the a/c on & off to help keep the windows from fogging up.
Every time the a/c cycles on, the volts momentarily drop from 14.5v to 12v, and the headlights momentarily dim/flicker, and the idle drops.
Is there a way to disable the a/c cycling on / off? I thought about pulling the a/c fuse for winter, but wasn’t sure if it would mess anything up in doing so.
BTW, it is a 99 Sport 5-speed.
Thanks!
jldiaz 01-13-2005 10:49
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Re: Defroster / A/C question
The compressor is controlled by the PCM, and that can't be user-modified. It signals the Idle Adjusting Motor at the same time so that RPMs are sustained. Is your IAC Motor allright? How long is "Momentarily"?
If you pull fuses or otherwise disconnect the compressor, you may get a MIL (Check engine light) that should go off after a few driving cycles. Otherwise, do you have a way to turn it off afterwards (scanner)?
Well I noticed yesterday that my ammeter drops drastically when I switch over to defroster.... I could hear the a/c kick on, and I understand why it does, but the voltage drop seems drastic to me because I have a low idle problem....and that may be my whole problem is the low idle (possibly in need of a TPS adjustment).....Ammeter at idle is usually around 14V - when I switch to defroster the compressor kicks on and voltage drops to roughly 11v - almost in the red..... Idle is around 300 (low huh?) but jumps up to around 750 when the compressor cycles on.....and my lights dim as in the post below....
Would bumping up the throttle stop adjustment screw help any?
Anyway - I did a search and found this thread and since there was no follow-up, I was wondering if anyone had done this - and if it caused any problems??
_____________________________________________________________
Crown 01-13-2005 10:14
--------------------------------------------------------------------------------
Defroster / A/C question
Hi all,
Evidently, when the defroster is on, it also cycles the a/c on & off to help keep the windows from fogging up.
Every time the a/c cycles on, the volts momentarily drop from 14.5v to 12v, and the headlights momentarily dim/flicker, and the idle drops.
Is there a way to disable the a/c cycling on / off? I thought about pulling the a/c fuse for winter, but wasn’t sure if it would mess anything up in doing so.
BTW, it is a 99 Sport 5-speed.
Thanks!
jldiaz 01-13-2005 10:49
--------------------------------------------------------------------------------
Re: Defroster / A/C question
The compressor is controlled by the PCM, and that can't be user-modified. It signals the Idle Adjusting Motor at the same time so that RPMs are sustained. Is your IAC Motor allright? How long is "Momentarily"?
If you pull fuses or otherwise disconnect the compressor, you may get a MIL (Check engine light) that should go off after a few driving cycles. Otherwise, do you have a way to turn it off afterwards (scanner)?