C3 Turn signal short?!

Kap142 · 07-07-2010, 10:32 AM

OK gang this is Ken's puzzle for this month is.........

I keep blowing turn signal fuses. Let me tell you what I've done and found (or not found) so far. I'll replace the fuse (with the engine off) and the turn signals will function as intended. I start the car and the turn signals work just fine for several miles, but (it seems) that when I turn the ignition off something causes the fuse to blow. When I again start the engine turn signals are gone and the fuse is now blown, again.

I can find no damaged or grounded wire, as a matter of fact I have replaced several older poor splices that some bubba had done just in case.

I can find no super heated or melted wires.

Part of my confusion comes from the fact that they will initially work after fuse replacement and being driven then malfunction and blow the fuse.

Any ideas guys?

vettejack · 07-07-2010, 11:55 AM

In some cases, maybe like yours, 'Bubba' may have installed the wrong amped fuse. If things work fine with no 'load' (engine running only), and things start to go haywire when u actually drive, then additional loading of the fuse could be taking place. You might have to bump up from a 5 amp to a 10 amp for example. Let others chime in and see if they agree with my humble assessment before you try changing fuses Ken. Gotta protect Goldie first...opinions and/or technical advice/suggestions like mine need to be colaborated!

Just my 2 cents...

Kap142 · 07-07-2010, 01:10 PM

Thanks my friend. I am running the perscribed 20amp fuses but something is f*ckin goofy here.

palmbeachvette76 · 07-07-2010, 05:51 PM

If I remember correctly the directional lights share their fuse with the back up lamps so you may want to check the backup light switch and the lamps themselves. There might be a short there that isn't related to the directional lamps that's causing the fuse to blow. Might even want to try disconnecting the wire to the backup lamp switch and see if it does anything, but your right this is a very odd problem, hope you figure it out.

The only other thing I can think of is something rubbing inside the steering column when the key switch is turned off, doesn't make sense but seems to be the source of the short, or at least when the short occurs. of course this only applies if your key switch is in the column and not the dash

Kap142 · 07-08-2010, 11:16 AM

Thanks Palmbeachvette76. With the help of your advise and some direction from the national C3 forum I did exactly as you said. I unplugged the connector, replaced the fuse and everything works just as the factory intended (except, of course, the back up lights). Now I just need to figure out if it's the switch or something else in that circuit and remedy that.

Thanks,

Ken

palmbeachvette76 · 07-08-2010, 12:58 PM

Right on brother, glad it worked out, well at least narrowed things down and who needs those pesky backup lights anyway

vettejack · 07-09-2010, 12:57 PM

If u haven't tried here...

http://www.c3vr.com

go to that website, of which I'm a life member. Its a dedicated C3 site and they have answered just about every question I've had to post in the past.

Good bunch of guys. Just post your questions in the appropiate arena, as in "C3 Electrical", and I'd betcha you could get your answer!

Kap142 · 07-09-2010, 05:34 PM

Since we were over I have become a part of the C3 Regrestry too but even another great source is Corvette Forum. It, too is nationwide and has some deep experience bases.

Now I just need a simple way to figure out if it's the wiring going to the back up lights, the switch itself or the receptacles.

Thanks Jack.

Ken

palmbeachvette76 · 07-09-2010, 06:34 PM

To track down the switch or wiring you'll need either a test light or a multimeter. If you have a multimeter you can use the ohm setting and put one lead on each wire from the switch and see if it works or not. One way it should show no reading on the meter and when you switch the switch you should get continuety.

Another simple thing would be pulling the rear lamps and inspect the bulbs for starters then remove the bulbs and use your test light or meter to check for power when the switch is engaged.

I never asked, but is your car an auto or manual trans

Kap142 · 07-09-2010, 07:46 PM

Alrighty here. It's a manual 4 speed but pls realize that ohms are what my dope smoking buddy in college 40 years ago used to talk about.

Ya gotta get far more step by step and detailed before my (I'd rather look at a cute figure) then figure out an ohms brain will understand. I do have an ohm meter but really don't know how to have it tell me anything that would roughly translate to english.

I do so appreciate the help. believe me.

Do I need to reconnect the back up light connector to test as you've suggested above? Bulbs look good and I don't see any real corrision in the sockets them selves, nor at this point do I see any fried wires.