Register or Log In To remove these advertisements. |
|
|
|
Thread Tools | Display Modes |
06-25-2009, 12:41 AM | #1 |
Registered User
Join Date: Nov 2008
Location: Tempe, AZ
Posts: 9
|
Volts drop when A/C is on
Newbee here, I have a 1987 SWB when I turn on the A/C my volts drop big time could the reason be the altenator.
|
06-25-2009, 05:17 AM | #2 |
Registered User
Join Date: May 2007
Location: CO
Posts: 474
|
Re: Volts drop when A/C is on
If it's at idle, that's to be expected. Does it rise with some more RPMs? If so, you should be ok.
|
06-25-2009, 06:39 AM | #3 |
Arrived on a Pale Horse
Join Date: Mar 2007
Location: SnagTown Indiana
Posts: 2,524
|
Re: Volts drop when A/C is on
Some drop is to be expected at idle as Prong said. Are you measuring the volts with the stock guage or a voltmeter? The volts shouldn't go down a lot like down into the 10 or 9 or 8 range, definitely a problem if it goes that far. Welcome to the site too, by the way.
__________________
Jason 87 V30 350TBI/400 White w/Boss V-plow 89 R3500 CC SRW |
06-25-2009, 08:35 AM | #4 |
Registered User
Join Date: Apr 2005
Location: Austin, TX
Posts: 1,224
|
Re: Volts drop when A/C is on
The short answer is yes, it could be the alternator. But it could be a lot of other things too. Need a lot more details before a definitive answer can be given.
__________________
- Greg |
06-25-2009, 09:17 AM | #5 |
On a budget like Fred Sanford
Join Date: Oct 2005
Location: Topeka, KS
Posts: 2,031
|
Re: Volts drop when A/C is on
The a/c and hvac fan both pull a significant load on the electrical system. Like said above, unless volts are dropping below 12V then it's nothing to worry about. I've got a 100amp alternator on my truck and when the a/c is on max/high and the electric radiator fan is on, my voltmeter drops to 12.5V at idle (I normally see 14V at idle).
__________________
'85 Silverado swb: 383 stroker, 10.5:1, vortec heads, 232/238 roller cam, RPM air gap, performer 750 carb, stainless longtubes, 3" duals/super 44's, T56/4.11 383ci build / exterior refresh thread '98 Camaro z28: 370ci twin turbo 370ci build '01 Tahoe LT 4x4: 5.3, longtubes/ory, magnaflow duals, custom tune....wife's DD |
Bookmarks |
|
|