Turn signal voodoo

[spidklr]

Two turn signal questions -

In trying to isolate the cause of a very occasional dead battery I noticed that sometimes the right turn signal gets stuck on (constant, not flashing) when the ignition is off (picture)


One Eye'd Hilde

Provided the driver (mostly me) remembers to look, this can be fixed, but circumstantial evidence points to this as the dead battery cause. Do they all do this?

Question 2 - all three drivers of this car noted that it seemed strange how far you have to turn the steering wheel to cancel the turn signal - about 190 degrees, aka half way around plus a bit.

When I had the steering wheel off the car to straighten it a few months ago I noted that the wee metal prong whose job it is to cancel the blinkers is at driver's left in the steering column, whilst the arc-shaped metal what-cha-ma-call-it that does the cancelling is at driver's *right* when the steering wheel is straight ahead. It struck me that perhaps that was backward or upside down, and that if the metal arc were at driver's left, the turn-signal-cancelification would happen at about 30 degrees rotation instead of 190.

Is that hunch correct? Should I try to flip or rotate the part that travels with the steering wheel 180 degrees?

[darrin]

as to issue 1, that's by design -- it's a parking light that can be illuminated when parking on narrow european streets at night.

Not sure on issue 2 -- but agree that the turn signal should disengage a lot quicker.

As to dead battery, does your interior dome light work when you open your driver's door? The switch that activates the dome light can go bad and when it does on a Carrera (not necessarily true on earlier 911s), it leaves the electric window circuit activated, which can slowly (over a few days) drain a battery. Of course, leaving the parking light on can do the same thing too.

[spidklr]

Now that is interesting. The dome light itself works but only if I manually turn it on by rocking it into the on position - the door switch to turn it on doesn't make the light illuminate.

[porschenut]

The parking light comes on when the turn signal stalk is set in the left or right position with the ignition switch in the off position. If the stalk is centered the parking lights should not be illuminated.

Hard to imagine how a dead battery can power a light bulb, don'tcha think? I'm not buying that theory.

You need to specify when you post that you have a targa. The dome light operation is different in a targa than it is in a coupe. Consult your owners manual to make sure you know what position is ON and what position is activated by the door switches. I don't have my targa anymore but as I recall it is only intended to illuminate the back seat area, which I found annoying.

[spidklr]

Thanks!

Yes, it's a Targa (though I imagined the turn signal operation to be the same across the body styles. The idea about the dome light was darrin's, not mine)

In terms of the battery the theory was that, if left to sit with those lights on, the light bulbs use up the battery to the point where the starter won't engage.

So, um, yes, a dead battery would not power a light. I get that. While the lights are on, however, I'm fairly sure electrons are leaving the battery, and it's slowly draining. :-)

[RSBob]

You probably need a new turn signal stalk/switch.

[targa80]

Several questions come to mind with your dead battery issue since leaving the marker lights on overnight should not kill your battery if the electrical circuits are all functional.

1. What is the charging voltage when engine is running? Should be ~14.5 volts.
2. How old is the battery? I owned an Optimum battery that went bad in less than a year and would not hold a charge. I had to jump start the car, had the battery tested and sure enough it had a bad cell.

The best way to isolate a power drain would be with an amp meter set in series with the battery. Leave the ignition off and remove fuses/relays one at a time while watching the meter reading. Be aware that there is always a minimum drain from circuits that are always on like the clock, and or car radio station memory or any after market add one.

[spidklr]

Thanks all - I have done a little troubleshooting but not much. Meter in series with the battery neg terminal, engine off, didn't show anything more than barely measurable trickle, and the charge seems to be fine based on measuring voltage across the two battery contacts with the engine running. Both the alternator and the battery are new in the past 6 months (alternator was replaced b/c shop found the bearing starting to bind, rather than a charging issue. The previous battery seemed short-lived. It came from the PO and was undated, so I can't be certain - but it was most definitely dead/ruined.)

It seems to be an intermittent thing - maybe a loose connection instead of a constant drain. It's happened 2-3 times in about 6 months. I had fallen into a habit of just ignoring it :-)

[Charles Freeborn]

These old cars spring leaks of all kinds.... I've taken to disconnecting the battery when parked for more than a day or so, and putting it on a battery tender pretty much all the time it's parked. If there's a short of any magnitude it will blow a fuse and then you've got a search on your hands. The Bosch harness is pretty darned logical and reliable. The most likely cause of electrical problems is aftermarket stereo / alarm installs. Ask me how I know...

The turn signal cancel device is held onto the back side of the steering wheel by 3 screws and can be positioned at 120º intervals. As I recall, you want the prong at 9:00. As said, you want the signals in the off position when parked, unless you want the parking light on.
-C

[Bob Kontak]

Originally Posted by Charles Freeborn

These old cars spring leaks of all kinds.... I've taken to disconnecting the battery when parked for more than a day or so

This type of bayonet jobbie works well for me.

Knife-Blade Switches - Wirthco Engineering, Inc.

[Charles Freeborn]

Yep. That'll do it. Or you can go all racer and get the handle on the dash/cable operated type. I think they run about $150.

[spidklr]

Well, you guys inspired me to fix my dome light. Nice to have it working - and now that I know how it works, that can't be the battery drain :-).