Turn signal fuse blowing

[Bob Kontak]

81 SC. High beam stalk is in need of replacement or tweaking as when lows beams are turned on they are "low" for a split second then revert to high.

That said, turn signal fuses are blowing - not instantly - but blowing regularly.

Can the headlight high beam issue and turn signal problem be interrelated?

I can track down a simple short, but if the stalk assy can cause both problems would be a nice heads up.

Thanks.

[Tippy]

I suspect there is correlation.

[86 911 Targa]

Originally Posted by Bob Kontak

81 SC. High beam stalk is in need of replacement or tweaking as when lows beams are turned on they are "low" for a split second then revert to high.

That said, turn signal fuses are blowing - not instantly - but blowing regularly.

Can the headlight high beam issue and turn signal problem be interrelated?

I can track down a simple short, but if the stalk assy can cause both problems would be a nice heads up.

Thanks.

Hope this helps.

If not, pm me.

Good luck,

Gerry


turn signal switch quick fix pictures

[Bob Kontak]

From the standpoint of being in the same stalk, definitely.

I have mostly seen reference to just finding simple shorts elsewhere but since the two problems happened roughly at the same time - was just checking.

Going to try replacing fuse and see if I can isolate the fuse burning up to skinny down the search.

[Bob Kontak]

Gerry,

Thanks - that is a good thread.

[boyt911sc]

Bob,

Your problem lies within the turn signal assembly. Either locate it by inspecting and tweaking the switch contacts or install a known good one (???). I wish I could send my spare unit to you but that's not feasible because where I'm now (down under). While it could be fixable tweaking the TS assembly, it would take a lot of sensitive and serious adjusting.

Tony

[dshepp806]

Look closely at the contacts and gauge their integrity,..while looking to do a little bending, if needed. She' probably needs replacing, especially if you see things melted in there.

Aside, the headlamp relay mod should be installed (if not already).

Best,

Doyle

[Bob Kontak]

Thanks gents! Will report back when opened. I bet it's toast or close to toast. Especially if melting has occurred.

Only 31 years old.................

[Bob Kontak]

Turn signal fuse blows when car is placed in reverse. The switch at the trans is fine but my connector ends that plug into it are beat and they short out when the switch is engaged. Any ideas on where to source the male connectors?

[timmy2]

I think they are NLA. Cut them off, carefully drill out wire and solder them back on the wires may be worth trying.

[Bob Kontak]

Originally Posted by timmy2

............Cut them off, carefully drill out wire and solder them back ...........

Thanks Timmy2 - Once in there today I found that I had repaired the connectors pretty well from an issue I had a year or two back. I had used the inside metal sleeve of a wire connector (plastic sheathed tube type) and squished and soldered the upstream wire into it. Fit into the switch pretty well then I zip tied the boot.

After isolating the front and back set of wires from the switch, I found no shorts. What I did find is that the back up light switch, when engaged - without wires attached - will short to ground. Disengaged, no grounding.

I also have an odd issue that I do not understand. With the negative battery terminal disconnected, key off and removed and back up wires disconnected, I get an audible MM signal between the connected positive battery post and random grounds inside the front trunk. It is about 7 ohms resistance. Negative cable to ground, no resistance. This seems odd, especially with the negative post disconnected. Also, many of the fuse hot sides connect to ground as well (cause they are connected to the battery, maybe?:-o). Is this a mini short somewhere? (maybe back to the high beam / turn signal stalk - which I have yet to touch)

[timmy2]

Could be a short in the stalk, could be your fuse panel on the back where the jumpers/buss bars connect. You may be seeing something through lighting and various control circuits to ground. (Remember, Porsche electrical here...)
I would isolate/remove all fuses and check every circuit to ground. Lift wires off of the fuse panel and trace and identify everything. Big job, but well worth the peace of mind. (Especially after the AH HA moment!)
Could the reverse switch be cracked internally and shorting to ground when it is activated through the case?
Put a ohmmeter on one terminal and the other lead to ground and actuate it. Do the same forthe other terminal.
Good luck, I hope you find it sooner rather than later.

[Bob Kontak]

Thanks much.

Not afraid of the toil as this is my hobby but your response confirms it ain't right.

Lemmie do some grunt work and report back.

[Bob Kontak]

Good God, this is going to be a learning adventure. I am fine with the aesthetics of the experience but, man, I am slow. I see all these relays and switches in the diagrams that the juice flow through and I struggle with putting it all together. Not an issue as I want to learn and it all makes sense eventually (one circuit at a time), but I am just slow.

I went to Lowe's and a Fluke is $140. I have a $50 Sperry that I am not happy with.

Timmy2 - I may be axin' for you phone number soon. Be advised. :-)

Re the trans switch - I lengthened the pin as it would not work after a Mayo Performance basic rebuild (2009). I may have made it too long and beat the snot out of it. i don't know.????

Here is a thread I started a couple years ago.

915 reverse light switch

[Bob Kontak]

Ok - Time to close the loose ends on this thread.

1. Reverse switch was not functioning until the make-shift pin I made reached the bottom of the internal switch spring travel. It was a real tight tolerance so I am sure I made the pin too long and I hammered the switch with the long pin until it failed internally and shorted to case blowing blinker/reverse light fuse.

New rev switch has correct engagement of switch "on" about half way through the spring travel. I put the shorter factory pin back in - all is well.

2. Did the Won procedure 86 911 Targa provided in post #3 for tired high/low beam switch. Was surprised at how just a little movement of the big beam made such a difference.

3. My reference to not understanding why fuse terminals (at least partially) grounded to the chassis was because I had the battery negative terminal disconnected AND the hood was up allowing continuity between certain fuse posts and chassis through the under hood (trunk) light. Hey, at least I found it. :-)

The end. Thanks to all.

[donagain1]

Hey Bob, I know that you put an official end to the thread here, but I did want to chime in just in case other readers stumble upon it while trying to troubleshoot their own woes.

It can be a futile exercise, and therefore not an ordinarily recommended procedure, to try to chase down a grounded "something" when metering resistance between the positive battery connector and ground when the battery is effectively disconnected. Not all electrical items are switched on/off, most notably the clock. Additionally, if the radio has been updated at some point to a newer one which has presets, there's a small amount of current flow required to keep the presets set... therefore a possibly higher resistance ground, but a resistance to ground nonetheless.

[Bob Kontak]

+ 1. Futile is a good word (see my #14 post).

Timmy2 also mentioned the clock to me in a PM while I was dumping my woes and "theories" on him offline.

I did get the MM audible signal to stop between fuse and chassis when I finally opened the closed luggage light switch but did not measure the resistance. I'll bet there was some resistance to ground (clock on same fuse) and more than with the luggage light ground path enabled. I don't know at what level of resistance the audible signal ceases.

Thanks for the clarity. Agree, the test requires being able to cut all know paths to ground (alarms/radios/open doors/clocks/engine lid lights - probably more stuff on newer cars)

[jluetjen]

I would recommend.

0) Download the wiring diagrams

1) Check that the wires going to the light switch as well as the ignition switch are connected to the correct leads. If they are, keep in mind that there are a few places to isolate portions of the circuits that might make it easier to trouble-shoot.

2) pulling the fuse that keeps blowing, and connect an ohm meter to a ground and the circuit side of the fuse block.

3) Watch the ohm meter and see if anything changes (or if the changes make sense given the wiring diagram) when you open the following connectors which are fairly easy to get to...

a) the firewall connectors under the dash
b) the connector for the indicator assembly under the steering column
c) the headlight fuses, or connectors for the relays (I don't remember know specifically how an SC is wired)

After much trial and error, I've found this an effective way to troubleshoot problems such as this after I had my electrical fire.

[Bob Kontak]

Good info jluetjen.

Multi meter (and time) is your friend and the later SC diagrams are pretty easy to use.

[86 911 Targa]

Originally Posted by Bob Kontak

Turn signal fuse blows when car is placed in reverse. The switch at the trans is fine but my connector ends that plug into it are beat and they short out when the switch is engaged. Any ideas on where to source the male connectors?

Try Blackbyrd on the used parts forum.