Fun with Electricity, PO Stuff #5 in the series, or is it #6? Options

[Spoke]

I figured out it was the left turn signal.

Keep in mind that the flasher relay doesn't know which side turnsignals are on. If the flasher relay works with the right turnsignal then the flasher and the wires to it are likely ok.

I had a guy stop by with similar issues with his left running lights on his '86 911. He put in a 25A fuse and it wouldn't blow but it would get hot. Fronts were dim and the rears were out.

Luckily with the 911, separate wires from the front running lights and rear running lights terminate at the fuse. Pulled both wires off and the fuse didn't get hot. Put the front wire on only and the running light lit up as expected and fuse didn't get hot. Put the rear wire on only and the fuse got hot and no lights in the rear. Turns out he had a short to ground on the rear light bucket.

Moral of the story is you likely have a short in and around the front or rear light buckets. Maybe try removing the wire to the left turnsignal in the rear and front turnsignal as well. See if you blow fuses. If you don't blow the fuse, then the issue is the front or rear light bucket.

With both front and rear wires disconnected, remove both front and rear bulbs and check resistance to chassis for the front and rear buckets. Both should be infinite.

[Tbrown4x4]

I have had good luck finding intermittent shorts by replacing the fuse that is blowing with a sealed beam headlight wired to the fuse panel. When the short would blow the fuse, instead it lights the headlight. When the normal circuit load is flowing, the filament passes the current without lighting.
I hope I explained that well enough.

Interesting idea. I have been looking for something creative like this so I can "see" what is going on.
I guess I would have to look for escaping smoke too since the headlight would take more than the amps rating of the fuse?

No smoke. The bulb filament is now part of the circuit and replaces the fuse. This allows normal current flow until the circuit shorts to ground, the the high current from the short circuit that WOULD pop the fuse, merely lights the bulb. Sealed beam headlight or fog light only.

[NARP74]

So the latest is that the fuse has stopped blowing, a couple of possible fixes for that one. An intermittent short in the trunk wiring for the tail light assembly, and I might have fried a relay. Will test the relay later. Got those both sorted.

I decided to put the incandescent bulbs back in the front turn signal housing and guess what? Things started working as I would expect. The LEDs are all still installed in the rear, incandescents up front. The blinkers function normally with no other lights on, 1 blink per second and both dash indicators are bright and flash at the same time. They also function correctly with parking lights and head lights on.

Looks like it might be something with the LED bulbs in that front position. I have no idea why they work in the rear but not the front. Same bulbs I think, just a different color in the back. I will swap and see what happens.

I can't be the only one trying to use LED bulbs for the front turn signals.

And here is one more oddity, with the LEDs in the front, no keys in the ignition, no lights on or anything running, if I hit the turn signals in either direction, there is enough current leakage to faintly light the LED bulbs, no blink, just a faint light. I get that they use less voltage but is that normal? Does that point to a turn signal switch issue?

And for the dial gauge indicators, are the arrows both supposed to light up no matter which way the turn signal is moved, or are they supposed to mirror the direction of the switch? I thought I had seen a previous discussion on this question.

[VaccaRabite]

Its the switch. You need a switch that is designed for LED bulbs. The LED bulbs draw too little power for the old switch to realize they are turned on, causing unexplained issues. There is a modern switch you can put it that might cure your issues.

I have full LEDs. On my car the switch won't blink the indicator on the dashboard. I have the new switch to install (and have had it for years now) but I have not gotten around to installing it.

Remember that LEDs are also Diodes. Incandescent bulbs are not, and don't care how they are wired. If there are crossed wires in the front somewhere the LEDs won't work.

Zach

[NARP74]

I have talked to a few people and verified on another car, that the lights do turn on when not running and no keys in the car. Just move the turn signal and running lights and warts if you have them illuminate. I never knew this.

[campbellcj]

Buying NOS or used old ones on Samba? Any good new sources? Do they still make them? I read a review of a cheap knockoff that sounded pretty bad. Who else has them?

Someone mentioned that a 75/76 Mk 1 VW Rabbit/Golf switch was compatible and I got a NOS one for $80 or so which worked perfectly.

Prior to changing the switch the specific symptom I had was that the hazards blinked and worked normally, the parking lights also were fine, and the Euro 'park mode' of the turn signal also worked fine, however in actual turn signal mode the lights would not blink.

[Spoke]

And for the dial gauge indicators, are the arrows both supposed to light up no matter which way the turn signal is moved, or are they supposed to mirror the direction of the switch? I thought I had seen a previous discussion on this question.

@NARP74

What year is your car? I've heard that for some early? '74 cars with single L/R indicator, some '73 tachs were used and both L and R were wired together. Have you seen yours before light separately? When going to LED turnsignals with the OEM flasher, both L and R indicators will light together and there's a chance that the opposite side turnsignal will light gently.

If using LEDs on all turnsignals, you need an LED-compatible flasher like EP26 with the K2 pin modded to ground.

[NARP74]

Car is a 74, but... it has a Gates dash conversion and I don't know anything about the gauges, if they are 911 or 914, could be some of each. I will have to take one or two out soon to answer some other questions anyway. I don't recall if the indicators ever worked separately or not.

I do have the EP26 that I purchased from you, 2 actually. I was going to do the LED upgrade on 2 cars if the first one went well. So much for that. I am going to put the 2nd relay in just for another test comparison. @Spoke do you do any mods to the EP26 or are they all the same?

It looks like 3 options at this point;
The switch, looking for a spare to test
The relay, easy to test since I have another
The LED bulbs, I could try another set

I have seen info on adding a load resister to non LED circuits. Is that in play here?

[Spoke]

Car is a 74, but... it has a Gates dash conversion and I don't know anything about the gauges, if they are 911 or 914, could be some of each. I will have to take one or two out soon to answer some other questions anyway. I don't recall if the indicators ever worked separately or not.

I do have the EP26 that I purchased from you, 2 actually. I was going to do the LED upgrade on 2 cars if the first one went well. So much for that. I am going to put the 2nd relay in just for another test comparison. @Spoke do you do any mods to the EP26 or are they all the same?

It looks like 3 options at this point;
The switch, looking for a spare to test
The relay, easy to test since I have another
The LED bulbs, I could try another set

I have seen info on adding a load resister to non LED circuits. Is that in play here?

@NARP74


Sounds like you do have funky things going on with your lights. If LEDs didn't work in the front but incandescents do, then it might mean the ground is not making contact in the front. Check to see if both filaments light up with turnsignals. Do the running lights work with bulbs and LEDs?
EP26 from me are modded for early tachs with separate L and R indicators and for later tachs with a single R/L indicator. The EP26 mod has to match the tach type.

The load resistor thing is for cars using LEDs with OEM flasher relays designed for incandescent bulbs. Not needed on your 914. You should be fine with EP26 as it can drive LEDs or incandescents.

[Spoke]

It gets worse. Why was this cut and bypassed?

The Blue/White wire goes to K2 which powers the common connection of the tach indicators. This is set up like OEM and IF your car has separate L and R wires going to the indicators, this wire needs to be reconnected to the socket. IF you car is set up to have both indicators flash together, then the cut is ok.

You need to pop out the tach and see where the wires to the indicators come from. One wire from each should connect together then to the Blue/White wire. If the other 2 are connected together, then your car is set up for both flashing together.

[majkos1]

Don't you have Five gauges ?
That's a Getty set-up

[NARP74]

Don't you have Five gauges ?
That's a Getty set-up

Yes I do and yes it is. I'll start another thread on the gauge, cut blue wire, turn signal issue. I want to finish the blinkers actually working issue first.

[87m491]

I can't be the only one trying to use LED bulbs for the front turn signals.

Nope just went nearly 100% LED (no headlights yet) in my 74 a few months ago. I had a problem with cheap dual "filament" brake tail light bulbs but fixed with better bulbs. The fronts worked right off. Is your/did you make your flasher relay LED compatible?

[NARP74]

I can't be the only one trying to use LED bulbs for the front turn signals.

Nope just went nearly 100% LED (no headlights yet) in my 74 a few months ago. I had a problem with cheap dual "filament" brake tail light bulbs but fixed with better bulbs. The fronts worked right off. Is your/did you make your flasher relay LED compatible?

I bought the flasher relay from Spoke, all ready to go, plug and play. I do have 2 of them. I will test the 2nd in the next day or two.