White Whale

Hello, all--

A few days ago, I started up my '87 Carrera and it was hesitant at first... starter didn't kick in and I had no "click" from the solenoid. After a second attempt, the car fired up after a few engine rotations. It's been cold here in New England, so I figured the battery might be going dead. The car was fine for a day or so, then one morning, the car was DEAD and wouldn't start. I immediately assumed the battery was finally shot, so I installed a new one. (As it turns out, stupid me, the old battery actually seems OK... reads 12.5 volts. I should have checked, and not just assumed.) A couple days later, same thing. Car was dead -- wouldn't start. When I hooked up jumper cables to a running car, my trunk light did NOT come on, nor did the car start. After a second or third try, the car started, and all the lights came back.

Here's what else I've found: When I open the doors, the electrical things such as dome lights work. I measured 12.5 volts with ignition off (I'd measured about 14.5 with engine running before.) Also, headlights never dimmed... from these things, I assumed the alternator is OK... it appears to be charging. When I try to start the car now, the starter tries to turn ONCE, then everything goes dead... like a weak battery. Everything in the car then dies... even the dome lights. Oddly, the battery still measures 12.5 volts. Here's the bizarre part: If I wait a few minutes, the dome lights will come back (even headlights will work), but car still won't start. If I try again, everything in the car dies AGAIN. But the battery still isn't dead... it still reads about 12.5 volts! Maybe there just isn't enough amperage available?

I considered a faulty ignition switch, but people usually describe a bad switch when talking about hard-to-turn keys, or flickering headlights, etc. Other things on the list of possibilities are starter solenoid, voltage regulator (although it's not overcharging), or alternator. Right now, the car doesn't want to start at all... although it might if I jump it.

Any ideas?

Conked out in Connecticut,

--Steve

1987 Carrera
1979 Les Paul 25/50

PorschePhD

Steve,

Try this first.....Have you checked you grounds? This sound just like a ground issue where there is enough corrosion to cause a current routing issue. It will get of one or two runs then once gets hot looses connection or can not supply enough current to deal with the amperage coming across. Check the main ground coming off of the battery as well as the cable of the positive. Even though the ends may look good I have seen where corrosion works its way up into the shielding and through the strands.

The more I reread this post I say it is a current issue with corrosion as the main culprit. <img border="0" alt="[jumper]" title="" src="graemlins/jumper.gif" />

White Whale

Stephen--

Thanks for the lead. I should check other ground issues, too, such as transmission ground straps? The battery wires are actually in great shape... and they have good contact with the battery, especially since I just put a new one in.

I'll check this out more thoroughly, though.

Thanks,

--Steve

P.S. I'll bet your 996 must be an absolute blast!

Porschephanatic

Stephen gave you some good advice. You stated that "the battery still isn't dead,it still reads 12.5 volts." If you have someone to help you, read the voltmeter before, during, and after your assistant tries to crank the engine, putting the battery "under load". If it holds reasonably steady @10-12.5VDC,(there will be some drop) your battery is probably fine. If it drops to 0VDC, it's shot. Hope this helps.

PorschePhD

Definitely check the other straps, although the entire car going dead would indicate a current issue at the main leads in. Also don't forget a battery can have 5 good cells and showing 12.5 yet when a load is applied the 6th cell goes to H in a hand basket. The only way to truly tell if it is all good is to test with a load tester and see what stable volts are under load as well as amperage. You have a new battery so you should be fine there.

White Whale

Hi, guys--

Previous owner installed one of those quick-release ground strap disconnects off the battery... for shutting off battery during long storage periods. It proved to be loose/separated slightly, just enough to cause current continuity problems. I think the culprit has been solved. Thanks for the good leads!

--Steve