PCA SDR

This one has me stumped.

85 carrera.

I washed my car yesterday. Afterwords, when I tried to
start it, it turned over a bit, but would not start.

Now it will not start at all.

The battery checks out fine with volt meter - 12.7 v.
But there is no electricity to ANYTHING.
no lights. no radio. and engine will not turn over.

if i connect a test light to the battery pos and to
the body for ground, light does not come on.
if i connect test light to pos and neg posts, it does come on.

anyone have any idea where to start looking?

I would start at disconnecting battery neg and cleaning the terminals at both ends of neg cable. then before connecting it back, do a resistance check of the neg cable from the part the battery connects to and some other ground nearby.

Thank you. I will check resistance, but what
result will show good resistance?

The battery is pretty new, so there is no
corrosion on posts or cables.

Any other ideas out there?

Should be almost zero resistance. If there is any resistance it means there is a bad ground connection.

My saga continues.

Checked ground strap at tranny.

Removed and cleaned ground strap at battery.

Battery sat disconnected for a couple of days.

reconnected battery, and luggage light came on.

turned ignition key and all gauges came to life.

engaged starter - CLICK - then all power gone.

is this possibly a bad battery? maybe with a short?

if you think the battery is bad, remove it and have it bench tested at you local kragen/sears/pepboys/etc.

Well, my local repair shop, All German, suggested
that I put jumper cables on the battery and try
starting it with another car. So I did.

When I first turned on the key, all gauges lit up.
But when I tried to crank the engine, everything went
dead again.

I am going to take the battery for a test next.

Is it possible that a bad starter could act like this?

johnrix wrote:Well, my local repair shop, All German, suggested
that I put jumper cables on the battery and try
starting it with another car. So I did.

When I first turned on the key, all gauges lit up.
But when I tried to crank the engine, everything went
dead again.

I am going to take the battery for a test next.

Is it possible that a bad starter could act like this?

John:

1) Check ground strap from (-) on battery to chassis. Rust? Weird spacer? Water after washing it?
2) Re-check (+) connections to battery ..... and check (+) connection at the starter. Actually, check all connections and wires at starter/solenoid. Clean? Corroded? Wet (shouldn't matter if wet, but look anyway)?

If you have a jumper battery, leave connected to your in-car battery and try turning starter/running engine with both batteries connected ... then disconnect batteries from each other (jumper from in-car). Engine dies?

Might be a bad cell in your in-car battery. One bad cell can cause weird electrical behaviors. Have you got another car to swap out a battery with? Try another battery (Loaner)?

I use portable batteries for work. I have a deep-cycle battery that appears to hold a charge when re-charged. However, after only 15-minutes of low-amp use, it drops to 8 volts (from 12.9). It use to hold a 12 to 10-volt charge all day. Final analysis. Battery is tired. Too many charge-discharge cycles. Time to replace.

Good luck!

the saga continues.
took battery to autozone and had it
tested under load. Checked out fine.

brought battery home - mind you it has
been out of the car for a few days - and reconnected
it.

Lights come on, dash guages come on.
Turn key, hear a click coming from the
rear of the car, and all is dead again.

So, when the elec. power is available,
something that has shorted out previously
has cooled off or whatever. But elec. to that
whatever causes it to short/fail again.
After some time (don't know how long) it
un-shorts, and elec is restored.

Not sure where click noise is coming from.
Will have to get my lovely helper to give me
a hand next time, so I can put my head in the
engine bay and see if I can tell where the click
comes from.

Any suggestions from you p-car lovers?

John Rix

Click most likely is from front of motor and is the starter solenoid clicking to engage starter gear, but not enough juice is passing to turn starter. Question, when you were jump starting the car, where were cables connected to?

well, the cables were connected to the battery,
in the trunk.

Is it possible that the DME relay would cause loss of
all electricity if it is failing.
I was just out at the car. In the past days, I could reconnect the
battery and the lights would come on. I just tried that, and no
light.
So I thought I would tap the DME relay. After tapping, I connected
the battery and there was light.

Problem still exists...

Help please

Removed battery, cleaned ground.
Took battery to AutoZone for a load test.
Battery tests out ok.

Next day, put battery back in car.
When I connected it, trunk light came on.
Turned ignition switch to aux position, and guages came on.
Turned key all the way.
Heard one quick click coming from rear
of car,
the guages, lights, etc went dead.
And, of course, the engine did not crank.

johnrix wrote:Problem still exists...

Help please

Removed battery, cleaned ground.
Took battery to AutoZone for a load test.
Battery tests out ok.

Next day, put battery back in car.
When I connected it, trunk light came on.
Turned ignition switch to aux position, and guages came on.
Turned key all the way.
Heard one quick click coming from rear
of car,
the guages, lights, etc went dead.
And, of course, the engine did not crank.

John,
Why don't you take the car to your local repair shop?
This has been going on for over 2 1/2 weeks now...
Wouldn't you rather drive it?
I decent Porsche tech would have that diagnosed in an hour on his hoist...
And you know what they say about free advice??
Well free advice on the internet is only worth half of that.

That being said I can't sit by while you waste another perfect weekend working on it instead of driving it. So here we go:

Car in neutral
Emergency brake on
Go the the back and remove the black plastic cover off the electrical board. (very left rear of car)
Remove the 14-pin electrical plug (be careful not to break it-its 25 years old)
Now make a jumper wire (12-gauge) to bridge pins #1 and #14
(They are marked and on opposite diagonal corners)

If the motor cranks when you bridge 1 & 14 the starter is good.
If it clicks and you get a big arc at the jumper you need a starter.

If the starter works with the jumper and not the key you have insufficient current getting to the starter from the ignition switch and you need to find and repair the bad connection.

This is just a rough outline and there could be other factors contributing to this problem. Be sure to check the engine ground strap which is hidden under the transmission mount and bolts to a stud on the chassis directly forward of the right transmission mount.

BTW- If it does crank with the jumper and not the key, you can turn the key on, use the jumper, and it will start. Then plug the 14-pin connector back on and drive it into your local shop and you will save the tow.

Good luck

Steve,
I knew if you finally read my thread, that you would
point me straight to what to check.

I followed your instructions, with the jumper,
and "click", then nothing. I did not see an arc,
but that may have been because my hand was
in the way.

Tried again, but at that point it did nothing. I assume
the "click" must be causing a short(?) that does not
un-do for a while.

You have saved my life - well, maybe just my sanity.
If I remove the starter, can I have it tested - or do
I even need to?

Thanks again, and I hope to see you, and the rest of
the members at AX this year. Have been going thru some
really tight times, but expect to come out of them this year.

John Rix