Both turn signal indicators flashing??!
 

Ok,
This has been an ongoing peculiarity for as long as I've owned the car so I may as well ask this question while dealing with my recent other electrical woes.

Why do the indicators initially indicate correctly then suddenly both flash at half the original intensity (like hazards)?

Also, my license plate lights have suddenly quit working. Recent bodywork was accesed through the left rear tail light lens opening and I've found a wire (two whitish ones in in one with a rubber plug on the end) were broken and the guy just stuffed it up inside the bumper to hide it... To top it off, alternator light won't extinguish for first time ever...jeez.

Any suggestions? :(

Ryan

bump. come on guys, somebody's seen this before!

Turn signals flashing half power - missing ground Brown.
There was a similar post a couple of days ago, but it's prob on page 5 by now!

It sounds as though you have more than one prob.

I suggest cleaning your two 14 pin plugs, clean with alcohol
then put dielectric grease on them (a conductive grease)
Then one fuse box at a time, take the fuses out lay them in a line so they go back correctly, clean the fuses clean the fuse holders, put the the same dielectric grease, also check tension of the fuse holders.

Then check all the elctrics if something still doesn't work post again
Jeff
911T

Jeff,
Thanks for replying...guess I need to go look for that post, huh?!
You mention 'ground brown'...what exactly do you mean? I have a poor ground somewhere and the wire should be brown?

I didn't think I had but one 14-pin connector, the one in the engine compartment. Where's the second? I checked my 14-pin tonight and it looked good and the row of fuses in the trunk are all ok, but I didn't try checking their contact points...

Have any idea what fuse the license plate lights are on? I was suspicious of the voltage regulator causing my other problems, but I checked the battery (between 10 and 11 volts due to repeated starts without charging) and when started put my voltmeter across the overhead light on the driver side...just popped it out...and the voltage didn't change. Doesn't sound like I'm charging, huh? The belt tension is fine.
:(
Ryan

Start with the most serious first.
 

You have so many electrical problems happening simultaneously, the only way to start is to isolate the problems. They could be related.

I would pull the fuses to the turn signals and to the license plate lights, and anything else electrical that is not working correctly.

A grounded circuit on the hot side of one of these could pull down the battery leading to the alternator light issue. Recharge your battery and see if the altenator light goes out. Keep the fuses out while you check this.

If this solves the alternator problem, move to the others by replacing one fuse at a time. I'd start with the turn signals and see if they work without the license plate light powered. Use the wiring schematic on this site as an aid in troubleshooting. You'll need a volt/ohmeter to do some checking. I'm assuming the turnsignal and the license plate light are on separate circuits. You can verify this by looking at the schematic.

I'd save the license plate light for the very last since it's the least critical.

Post back what you find.

Autobohnrun,

Thanks. Good point. I think they're going to be found to be related as well. Here's a theory to follow-up - my car just came back from the body shop Friday (what a coincidence). They had to pull the left side rear tail light assembly to access the rear quarter panel. Tonight I pulled out the assembly to see what might have happened. Sure enough, I found a hollow black wire (conduit?! can't think of the right word) with two whitish wires inside. They were broken off from whatever they attached to and it had a black rubber 'nipple' plug for fitting it somewhere into the body. I don't think these are for the license plate lights, I can see those both going where they're supposed to go and they're not for the taillight itself, that one is there and they are working.

My battery is only showing in the neighborhood of 10 volts now and this battery was purchased just a month ago, so eliminate 'old battery' syndrome. Are you suggesting that if the battery has been significantly discharged that they may be the reason why my light hasn't extinguished quickly as it ordinarily should? My only problem with this is that I tested across an interior light with a voltmeter with the car running, expecting to see regulated voltage (i.e. higher than battery) and found it was the same as battery...revving the engine higher had no effect. Now what? Thanks for getting involved...may need to visit my wrench tomorrow morning.:(

Ryan

Had the same problem on my 914 (first blink was OK then both interior blinkers blinked at half intensity). Replaced the turn signal relay and it went away.

But with all the other problems it sounds like a bad ground somewhere.

Jim

Jim,

Where's the turn signal relay on the 911?

SmileWavy

Ryan

Unfortunately, I'm speaking from SC experience and your model may be different. The alternator light works on the voltage difference alternator output and the battery. No difference, no alternator light. The battery is used to bootstrap the alternator field when you first start it. That's why the light comes on initially then goes out once the alternator output and voltage at the battery are the same. Click on "Alternator", then the "Alternator troubleshooting table" link on this page and it describes what I'm speaking of.

http://www.pelicanparts.com/catalog/shopcart/911M/por_911M_electr_main.htm

Once you get the battery charged back up with fuses removed from potential drains, then you will be able to see if it is charging. I'd hate to try to troubleshoot an alternator charging issue if there are shorts somewhere in the load wiring. Isolating the issues by pulling fuses will help.

I'll take a look at the schematic and see if anything else is apparent.

The two 14 pin plugs are both at rear left of car
They are either side of the plate on which your relays sit.

I higly reccommend you clean them both. many present faults can be cured and many future ones prevented.



Ground - Brown ....... All the ground wires are brown, if a ground is missing the 12v supplied to the bulb will travel through the wiring to another component and to it's ground to complete the circuit (in this case the other component is the other turn signal)
You now have two bulbs in "series" both are 12v bulbs but as they are in series they will "share the 12v ( 6 each) and glow accordingly.

The advice of autobonrun is good, forget about the number plate light for now.

Jeff

Ok, I have a Haynes schematic in front of me now. I don't have one for a 74, this is for a 77 but maybe someone can verify if the wiring is the same. Just adding some more information to my previous response.

As mentioned, the ground wire which is brown could be the problem. Unfortunately, the ground on the left front turn signal is shared by the left parking light, and left head light. The left rear turn signal shares a ground with the left stop/rear light. Likewise, the right signals share grounds. To check that you have a good ground (0 ohms), lift the brown wire at the left front turn signal and measure from the wire to a good known chassis ground. Do similarly for the right side.

However, your description of "dim lights flashing" points to the emergency flasher switch. Lights will be dim if either a socket is corroded or an additional load is added (eg. four bulbs rather than two intended). According to the schematic, the hazard flasher relay also functions as the turn signal flasher by supplying power through the hazard switch to BOTH TURN SIGNAL LIGHTS. The only way I see power can go to both left and right side turnsignals simultaneously is through the hazard warning switch; assuming your hot wires are not shorted together. Normally, activating the turn signal applies power just to one switch at a time. A quick check to see if the signals are being loaded down is to pull one of the turn signal fuses and see if the brightness of the other returns to normal.

With respect to the license plate lights, according to the schematic, they receive their power from fuse 2 (verify) on two grey wires. This should be the wires you say look white. Each bulb should have a separate brown wire that connects directly to ground. This problem should be unrelated to the turn signal issue.

Once you resolve the alternator issue, I'd take a quick look at the hazard switch contacts and make sure they are making and breaking. Again, get a wiring schematic and you can more easily follow this convoluted response. I don't want to send you on a wild goose chase and would feel better if you checked out this advice.

good luck

Thanks so much guys,

You've given me a lot of information to try and track down this problem(s). I've found the electrical schematic mentioned on the pelican website (65- cars) and studying it. I'll let you know what turns up tomorrow. I was supposed to take the car back to the body shop in the morning because the guy accidentally scratched up the top of the rear bumper with the taillight assembly while doing bodywork in the rear quarter panel. He didn't notice it until after shooting the panel...:(

Anyway, I think this electrical problem is going to take priority over 'pretty'. First things first, right? :D

Thanks again for your time on this,

Ryan

don't worry about the "pretty" part. i just spent a year making my targa a solid platform and am now selling it to build a turbo'd rs replica :D
once the bugs are out of your 911 you'll REALLY start to appreciate your german masterpiece.....reguardless of how it looksSmileWavy

I had the exact same problem... you would indicate and then a second later both flashed on in the dash at half intensity... Then I decided that for a 25 year old car... it might be an idea to overhaul the entire electrical system... so I did.. Interesting to see what kind of corrosion etc the electrical system suffers. I am sure you probably don't want to go that far but I am sure if you don't have a stock car, with the number of alarms and crap that gets put into a 20 year old car, the electrical system feels the strain...

Dana,

Replacing the entire electrical system sounds like a good investment to me. Mine's a daily driver...could afford a much more reliable car, but that just wouldn't be very fun at all now would it?! :p

Did you do the job yourself or did you have a shop perform it? I'd be curious of what the cost would be to have it done right...I live in the Midwest (Arkansas - Porsche capital of the U.S...)

I've gotta get to work this am, so I think I'm going to take it to the wrench for help with troubleshooting. I hate to do that but I'm time limited this week. :( Wish I could quit the job and just work full=time on the P-car!:D

Ryan

Ryan,

Can't remember without looking at the car but it was a 914. I think it was on the relay bd in the engine bay. Round relay. But listen to the other Gurus on this board, they know more than I.

Jim

The owners manual says that when your turn signal indicators do the half intensity flash it is telling you that you have a bulb out somewhere. Perhaps a short will also cause this?

Samokin,

It really said that somewhere in the manual?! I have my '74 owners manual and thought that I had read it cover to cover by now and don't recall that. I'll look again...after I get the car back from the wrench. :( Maybe the alternator light will be fixed by replacing the brushes...wrench says it will be a 3 hour ($180) job for the labor. Damn I wish I had my tools back! Divorce and no tools or garage is a PIA!

Turns out the brake light on that left side is out too...be careful when you take your car to the bodyshop. I'll bet the wires hanging down in the back of the quarter panel have something to do with the brake light and maybe the license plate lights as well. Maybe the electrical schematic for cars '65 and later on the pelican site will help...of course my wrench should figure it out.:rolleyes:

Ryan

Please let me know what the verdict was...

Rick

Me too! I've got the same "double signal" and no license plate lights.

My kids thought something was wrong with the signals, I thought they were supposed to do that (like if you leave the signal on and turn off the car the light burns steady (it is supposed to do that isn't it?)). After all, the driver knows which way he signaled!

You got it guys! As soon as I get word I'm, posting. I had a feeling I wasn't the only p-car driver seeing double! Of course I've only been experiencing the license plate lights problem for a coupe of days, so not related I would think..

Ryan

I had the problem with my directionals blinking fast. I swapped out the relay/flasher with one from Autozone. It slowed them down, but then both indicators were flashing even though only 1 side at a time was externally. I bought the original Hella relay/flasher and my flashers are back to normal.

Hmmm,
From what I've been reading on search threads and this one, most of the fixes have involved replacing the turn signal relay or tracking down poor grounds, as if they may start to signal correctly, but as soon as the bad ground is hit the turn signals are suddenly taken out of parallel and put into series, thus dividing the voltage (and thus the intensity) to each...and they both wind up illuminating. Slicker 'n snot... ;)

Ryan

Just spent the last 2 months going through each circuit on my 72 targa and yes I too started with the reported double blinking.

Things to check:

-bulb sockets, I cleaned mine with a bit of sand paper often dirty

-replace the turn signal bulbs with new ones, often the base or side terminals become coroded or may be sloppy in the socket after all these years

-check the fuse for dirt/corrosion at the contacts

-double check all your gounds

My solution was to change the bulb after all that work with a new one and B I N G O. The new bulb had a nice tight fix and perfectly clean to boot.

Pete

This may sound like a dumb question, but which bulb(s) did you change to solve the problem? All 4 bulbs for turn signals on the corners?

Ryan

I was lucky, one of the bulbs was not as bright as the others so I went for it. Do yourself a favor clean and inspect all of them, you will find all kinds of stuff in the sockets!

Pete

I had the same problem, 77 911S, it seemed to only happen at low rpm's. I blamed it on low output from alternator. It was worse when other electrical draw on the system ie wipers, radio.
I purchased a yellow top optima deep cycle battery. Fixed!:)

rsa,

Hmmm...I'm starting a rebuild on my alternator this afternoon...it will be interesting to see how this affects it. Interesting to me that a new battery fixed the problem. Once the starter engages and the alternator comes online, the voltage regulator should maintain voltage at 13.5-14.5. Battery should just be there for starting unless, like you say, at low rpm's the alternator drops offline momentarily forcing the battery to carry the load temporarily. I'll certainly let everyone know if the problem is related to this.SmileWavy

Ryan

I know this is an ancient thread, but I had exactly the same issue. All exterior turn signals worked fine, but usually the interior left and right turn indicators both flashed simultaneously at a dimmer level. The user manual says this indicates one of the four exterior bulbs are out. Mine were not out. Saw in another thread that replacing the flasher relay (located behind the fuel/oil level gauges) fixed the issue for one guy. Thought I would try just removing the relay and ‘polishing’ the four contacts on the bottom first. Removed it, polished with some sandpaper, re-installed the relay and viola, my interior turn indicators started working properly.

Thanks for this, Tom.

Both my turn indicators “flash” simultaneously so dimly that they are nearly impossible to see.

I’ve been putting off digging into the issue due to travel, but your post (and resurrection of this thread) has motivated me to take a stab at a fix sooner rather than later.

Of course, I’ll clean up all the grounds as part of the project as well!

Cheers!

Actually, I have the very same problem with the indicator lights. Will have to try this, too.

Also check your earth. I spent the weekend sorting out my lights and at one point the tail light flashed when the indicator was activated. I connected a new earth and everything works. I don't quite understand it but weak earth can get a lot of strange issues as well.

which year is the car in question? Maybe I missed it.

Older cars used bimetallic strips that complete the lamp circuit when cold (signals always started with “on”) and when they pass current they heat up and curl to break the circuit. How much current = how much heat = how much time to cool off. So losing a bulb blinks twice as fast since they do not get as warm. (half the current in a 2 bulb circuit for example)
If your lights are going dim and blinking slowly, you are drawing more current than you should be and the ALT light going on just confirms this. That sounds like a short of some sort, and it would appear to be between the blinker unit and the bulbs. I would check the housings first for damage or mixed up wires. They take a beating from accidents and weather/dirt.
You can isolate front from rear by pulling the fuses or just popping the bulbs out.
The front turn signals (i only have some g-body exp) are wired from the headlamp buckets with a ground (brown) lead, and then a lead for parking/marker lamps and a lead for the turn signal filament.
Good suggestions above around cleaning up/checking your grounds and pulling fuses to see what stops the current draw. Identify, isolate, annihilate.
If you can ID the year I can take a look at that diagram (assuming it exists) and find more targeted suggestions. Gd Lk!