Help: good battery no juice!

[Barenecessity]

I am terrible with electrical stuff. I got into my 83 911 SC this morning and there was no power to any instruments when I turned the key. Nothing worked, no fuel pump, nothing. The parking and dashboard lights worked when I pulled on the headlight switch. The dashboard clock worked as well. I hooked up the multimeter to the battery and it read 12.64 volts. The battery was well connected.

Anyone have any suggestions and pictures of where I should look next? Could it be one of the ground straps?

By way of background, I just had the engine removed by a local (good) mechanic to replace some of the hoses and gaskets in the rear of the engine. I got the car back three days ago and it's been running beautifully. I ran it yesterday with no problems. Today . . . all dead.

Thank you for your help
BN

[midnight911]

definitely check the ground strap by the tranny carrier. i had weak starter and battery and this was the culprit...was loose.

[Por_sha911]

Check the ignition switch

[ossiblue]

Originally Posted by Por_sha911

Check the ignition switch

+1!

First, check that the five prong plug connector is securely in the back of the switch (look under the dash.) The fact you have lights and clock means some of the electrical is good. Everything you describe as non-functioning is related in some way to the ignition switch. Also, check the 14-pin connectors in the engine compartment.

[Barenecessity]

Thank you for your responses. Ossieblue do you have a picture or diagram of the 14 pin connector in the engine bay?

[boyt911sc]

Originally Posted by Barenecessity

Thank you for your responses. Ossieblue do you have a picture or diagram of the 14 pin connector in the engine bay?

Bare,

I'll reserve my offer until we hear from Larry.

Tony

[tdw28210]

Ground strap...check it...that is my bet

[Joe Bob]

I'd be on the phone to your local (good) mechanic Monday AM.

[ossiblue]

Originally Posted by boyt911sc

Bare,

I'll reserve my offer until we hear from Larry.

Tony

Tony,

No need to wait. I have no pics to post and you're more experienced with later cars. I was just offering simple areas to check and not even sure if the 14-pin would account for a complete electrical/ignition shut down but since it's in the area where the work was done, it's a suspect.

[cdrik915]

A battery can shows a good voltage , but can have a bad amperes level.

Just try to replace it with a friend's one.


You'll see if i'm right or not.

[dave 911]

This sounds JUST like what happened to me last week, and it was a dead battery. The only electrical I had was to the clock, no warning lights or anything. The battery wouldn't charge at all, the charger kicked off when I hooked it up, but the battery did show voltage across the posts w/ a voltmeter. I took the battery (which was 12 years old btw so no surprise) to my FLAP and they confirmed it was bad.

Replaced the battery and all is good now....

[wwest]

Sometimes a "crust" will form inside a battery connection that is not readily visible. Small current loads get through but the 100 amps to run the starter will not. Remove the connections, clean and burnish the battery posts and the inside of the connectors....

[Barenecessity]

After much trial and error, I whittled the problem down to the ignition switch. I checked all of the grounding wires and connections in the engine compartment. Now I have to decide whether I buy the simple electrical switch for $117 or break down and spend a small fortune for the whole assembly ($700+).

Thank you Pelicaners for your help.