Re: Weather change and battery drain

by Mcarlo77 Tue Jul 09, 2013 11:33 pm

You need to measure across the battery terminals and see what you get.

by JiMi_DRiX Tue Jul 09, 2013 11:43 pm

Mcarlo77 wrote:You need to measure across the battery terminals and see what you get.

I've done that, thats what I meant when the battery was reading 14v when the car was running, and 11.8v yesterday before I started it, I was testing both terminals. In the picture I was checking for a "draw", but I dont believe I'm doing it right, no way is there a 11v draw and my battery isnt dead the next day. Something isnt right, and either its something simple that just went right over my head, or...

by thatfnthing Wed Jul 10, 2013 10:25 am

JiMi_DRiX wrote:Heres a picture of what I'm doing.. setting the multimeter to DCV, and putting it line with the disconnected + terminal, and this is my reading. The reason why I think I'm doing something wrong is that I get the same kind of reading doing the same test in the other Monte.

JiMi_DRiX wrote:I've done that, thats what I meant when the battery was reading 14v when the car was running, and 11.8v yesterday before I started it, I was testing both terminals. In the picture I was checking for a "draw", but I dont believe I'm doing it right, no way is there a 11v draw and my battery isnt dead the next day. Something isnt right, and either its something simple that just went right over my head, or...

Yep, that's what I was describing. After looking around, it looks like most guys do it by checking for DC amps. Volts is the electrical "pressure" (i.e. speed of water through pipe) while amps is the "volume" (i.e. diameter of pipe), so amps should more accurately reveal how much juice is actually flowing. It might be 11.8 volts at a fraction of an amp, which amounts to a fast-moving trickle. I always used volts because amps on my meter was fried some time ago. Maybe time to get a new one... Smile

Also, take a look at this -- some good info here.

by pila Wed Jul 10, 2013 10:34 pm

At least it's an older car. Late models with electrical problems are 10 times worse to find problems.
I had one car years ago, that had draw from a bad wire in the trunk light. Pulling fuses one at a time can sometimes isolate the problem, but not always of course.
The headlight switch has it's own circuit breaker, so pulling fuses wont isolate head light stuff, or a bad switch .
Hope you find the problem.....

by JiMi_DRiX Wed Jul 10, 2013 10:55 pm

when the rain and lightning stops sometime this week, I'll test it again the right way by checking for amps not volts.

by JiMi_DRiX Thu Jul 11, 2013 10:05 pm

I did another test, this time the right way using Amps, and I got a reading of .02. the standing voltage was a little over 12v and the alternator is working well. maybe I don't drive it enough and it's being rough on the battery.

anyone have suggestions for nice battery cables and a cleaner way to connect accessories?

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