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davidhasper · Joined: 28 Jan 2005 Posts: 6 Location: NH

when I turn the key I hear a loud clicking and a busing coming from the back, can any1 help me figuer this out?

Smoothie · Posted: Fri Jan 28, 2005 9:28 pm Post subject:

The click should be the starter solenoid activating and the buzz'd be the fuel pump/s. Might just be a discharged battery - try a charge or jumpstart. If jumpstarting, let it charge a couple minutes and rev up the host vehicle to speed up the process before trying to start.
If that doesn't work, then you might need a new starter solenoid. Another possibility is oxidized connection/s at the battery or starter inhibiting current flow to the starter.
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"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

davidhasper · Joined: 28 Jan 2005 Posts: 6 Location: NH

Thank you for answering me. We jump started it and I kept the revs up for a minute then let it idle and it seemed fine so I drove it on the freeway {lights and radio off} thinking if the battery was low, I could charge it by driving it. Would that hurt the alternator? Anyway, I drove it on the freeway for about 5 minutes and didn't notice any power loss or shuddering like it was about to stall. I parked it and then tried to start it and it wouldn't go. Same problem... I guess I can have my battery tested and then go from there. The battery is almost 4 years old which I think is old for a car battery.

Smoothie · Posted: Sat Jan 29, 2005 1:45 pm Post subject:

Yeah it's most likely a worn out battery and can't hold a charge.
_________________
"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

davidhasper · Joined: 28 Jan 2005 Posts: 6 Location: NH

Smoothie · Posted: Sun Jan 30, 2005 8:47 am Post subject:

Your alternator's probably fine - apparently it's putting out sufficient current and the voltage's being regulated since you were able to drive it. -But it wouldn't hurt to monitor the running voltage to be sure. If you don't have a volt gauge, just temporarily hook up a multimeter. I use a cigarette lighter plug - attach the multimeter leads to it and plug it in.
As far as I know it is possible to wreck an alternator with a really bad battery - like one with a lot of internal resistance. I recently did some bench testing of a spare alternator and found the voltage output varied wildly and went way high while testing it alone, but when I added a battery to the circuit and tested again, the voltage stayed within appropriate limits, so the battery acts as a kind of buffer in the charging system. If it's not there (or if its' internal resistance is way high which would be similar to it not being there), then the voltage can go crazy (even with a good voltage regulator) and it's easy to conclude that running too long like that could damage a variety of electrical components in the car as well as the alternator itself. -But given that you were able to drive it and things weren't blowing up in your face, it's safe to say the batterys' internal resistance hadn't yet gone high enough to cause serious problems. Just install the new battery and check the running voltage. If it's good, you're good.
_________________
"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

numbbers · Posted: Mon Jan 31, 2005 10:26 am Post subject:

Five minutes is nowhere near enough to charge your battery. A completely discharge battery may take up to two hours to recharge off of the alternator.
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1980 924 Turbo