Weird electrical problem!

[fowljesse]

I just got a new battery for my key fob. Until now, the door locks worked, but the LED indicating the alarm was on was not working. It has always taken about 3 turns of the key to start the car; the first couple of times, it didn't click, or do anything. On the 3rd or 4th time, the car would start fine. The car started once, after replacing the fob battery, but barely had enough juice to turn over, after a short drive. I push started it, and on the way home, the tach, and speedo cut out intermittently, at the same time, and the clock goes dim at that time, too. After turning the car off, it doesn't have enough power to turn over, but it barely tries.
What the Heck?!

[crazycanadian]

Sounds like your battery crapped out... Better check your charging system as well...

[fowljesse]

Yeah. I had the battery recharged, and checked, and they said it's fine. It runs now, but died twice after about 10 minutes of idling, but started right back up.
Could the speedo, and tach problems be from a weak battery?
I ran it for about five minutes after disconnecting the battery, so I guess the alternator is fine. However, the battery shows 12.4 volts while the car is running, and about 12.5, when not.

[crazycanadian]

Yeah. I had the battery recharged, and checked, and they said it's fine. It runs now, but died twice after about 10 minutes of idling, but started right back up.
Could the speedo, and tach problems be from a weak battery?
I ran it for about five minutes after disconnecting the battery, so I guess the alternator is fine. However, the battery shows 12.4 volts while the car is running, and about 12.5, when not.

When the car is running with a multimeter your voltage should never drop below 13V at idle with all your factory accessorys running... If you are lower then that you have a problem with your alternator..

Fix it before tackling anything else... Low voltage problems do all kinds of screwed up things...

[wytbishop]

Yes the speedo and tach are related to the battery problem. It's almost definitely a charging problem.

[fowljesse]

Thanks, guys! I haven't experienced this before. It's always either worked, or not at all. It seems like it's charging a little bit, since it ran for a few minutes with the battery disconnected. I guess I'll get the Millenia alternator.

[fowljesse]

I took the alternator from the stock car, and everything is good Now, back to tuning, and replacing my broken motor mounts. It turns out that my alternator was putting out 12.6 volts. Just enough for me not to pinpoint the problem. This is how electronics treat me.

[wytbishop]

it's not personal. electrical hates everyone. electrical is a bee-otch!

[crazycanadian]

I took the alternator from the stock car, and everything is good Now, back to tuning, and replacing my broken motor mounts. It turns out that my alternator was putting out 12.6 volts. Just enough for me not to pinpoint the problem. This is how electronics treat me.

12.6V with the motor running is the dead give away that you have a charging system problem... I bet if you turned on all your factory accessories at idle your voltage would have started dropping...

When you really get to know electronics you'll figure out that they are pretty easy...

[fowljesse]

I meant that the problem wasn't noticeable until I put a multimeter on it. It kept just enough charge to run. I even disconnected the battery, and it ran fine for a few minutes. You're right, though; it didn't produce enough current to run anything.
The part of my brain that would understand electronics took a few hits, physical, and chemical. I've trid to understand.. So far, I get that it's like water pipes, and voltage is like the amount of water going through, and amperage is the pressure, or the other way around. I'm trying..