Electrical short in relay connector?, Turn signals dont work with Headlights on?? Options

[Zaney]

After making the swap to Engman's wonderful new fuse panel I only have one gremlin to chase down. Using Haynes electrical diagram with a 1974 USA teener I have narrowed it down to the Fog Light relay. Previously, the relay worked fine however, in reconnecting the relays into the new panel a short has developed.

Is it possible for the connections to come loose in the relay connector? Or am I barking up the wrong tree? I think I have it narrowed down to the #30 wire which is the red/black wire connected with the #30 red wire from the horn relay. (Horn doesn't beep either only relay clicks) These two wires connect to fog light portion of the panel.

What is the next step?

I have tried different relays with the same result- LED fuse lights up when fog light switch is pulled on. (IMG:style_emoticons/default/help.gif)

Any suggestions are very welcome!

Thanks!

[jr91472]

Funny but I have experienced the same problem. I have not upgraded my fuse panel (however). Very intermittent fog light failure (although the light in the switch always works, sometime the fog lights wouldn't come on).

I chase it down to what I thought was a bad relay. I replaced the relay about 1 month ago and so far no other problems . But here is the kicker, the so called "bad relay" tested out fine. Meaning I put it on the one of the headlight motors and....no problem.

So I don't think I have fixed anything.

(IMG:style_emoticons/default/popcorn[1].gif)

[ahdoman]

It is possible to put the round relays in one pin off. They will fit (ask me how I know). That woould cause a failure of the device the realy is intended for plus anything downstream of the power buss. Make sure the relay is in correctly.

[Zaney]

Ok, I purchased a new relay and a new relay socket.

I used the electrical diagram in Hanes for a USA 74 for the fog light relay.

The socket has an extra wire not to be used. I tested the socket for continuity to correctly id the wires to pin sockets. Connected the socket wires to the appropriate wires in the fuse panel and... nothing.

When used the extra 87a wire instead of the 87 the lights would come on without the key in the ignition and the fog light switch off? (IMG:style_emoticons/default/screwy.gif)

Where and how should I trace any issues backwards?

Any help is greatly appriciated (IMG:style_emoticons/default/smile.gif)

[904svo]

Ok, I purchased a new relay and a new relay socket.

I used the electrical diagram in Hanes for a USA 74 for the fog light relay.

The socket has an extra wire not to be used. I tested the socket for continuity to correctly id the wires to pin sockets. Connected the socket wires to the appropriate wires in the fuse panel and... nothing.

When used the extra 87a wire instead of the 87 the lights would come on without the key in the ignition and the fog light switch off? (IMG:style_emoticons/default/screwy.gif)

Where and how should I trace any issues backwards?

Any help is greatly appriciated (IMG:style_emoticons/default/smile.gif)

White/yellow to 87 on relay (normal open contact)
Red/black to 30 on relay (power from fuse #1)
White/blue to 85 on relay (relay winding power)
Gray/red to 86 on relay (relay winding to fog light switch this lead gets grounded
when Fog light switch is operated #30 on switch goes to ground (brown wire)

87a is normal close contact on relay.

Hope this helps you.

[Zaney]

Thanks! I will put my patience hat on and dive into this.

Nate

[904svo]

PS

The fog lights only work when the Low Beam headlights are on!

[Zaney]

Could you clearify what the blue/white "winding power" does and/or connects to?

Muchas gracias!

[904svo]

Could you clearify what the blue/white "winding power" does and/or connects to?

Muchas gracias!

My mistake, Porsche used the ground from the high beam headlight, thats
the White/blue wire #85 on relay. the relay gets power to operate from the
operated Fog light switch Black/blue #15 on switch which come from the
headlight switch. When the high beams are turn on the relay has 12 VDC
on both side and goes to a non operated state (Fog lights off) when the Low
beams are turn on the Fog light relay operates from the low resistance ground
through the head lamp bulb. (Fog lights on)

Hope this clears the operation up for you.

[Zaney]

Thought I would bring this question back from the dead.

I am trying to troubleshoot the fog lights. I already adapted the JWest flasher mod and swapped the fuse box over to the Engman panel. I only have this little gremlin to chase out and I will be finished with the electrical work. Prior to the Engman swap the flasher mod and fog lights worked great.

I have followed the threads and advice of many people to isolate the issue but every time I pull the fog light switch I pop fuse #8.

The only other thing that is different is that I deleted the side markers and are waiting to relocate them behind the wheel wells with modern AUDI lights.

Thanks (IMG:style_emoticons/default/beerchug.gif)

NAte

[Zaney]

Ok, I purchased a new relay and a new relay socket.

I used the electrical diagram in Hanes for a USA 74 for the fog light relay.

The socket has an extra wire not to be used. I tested the socket for continuity to correctly id the wires to pin sockets. Connected the socket wires to the appropriate wires in the fuse panel and... nothing.

When used the extra 87a wire instead of the 87 the lights would come on without the key in the ignition and the fog light switch off? (IMG:style_emoticons/default/screwy.gif)

Where and how should I trace any issues backwards?

Any help is greatly appriciated (IMG:style_emoticons/default/smile.gif)

White/yellow to 87 on relay (normal open contact)
Red/black to 30 on relay (power from fuse #1)
White/blue to 85 on relay (relay winding power)
Gray/red to 86 on relay (relay winding to fog light switch this lead gets grounded
when Fog light switch is operated #30 on switch goes to ground (brown wire)

87a is normal close contact on relay.

Hope this helps you.

Ok, here is what I have found out,
According to the wiring schematic from PP for a '74 the wires should be as follows, at least what I can read:

For J5 Fog Light Relay

BLK/RED 30 to S10 fuse (HORN WORKS)
Grey/RED 85 to K terminal on fog light switch (switch works and lights up)
White/Blue 86 to S1 fuse (high beams and panel high beam light work)
White/Yellow 87 to fog lights (No POWER)

extra wire for 87a has power to it without the key in ignition

Before I pull the fog light switch, I have power at the 30 pin and 87a pin on the relay. When I pull the fog light switch, the number 10 fuse pops.

Possible related issue, everything else works with the lights except I do not have hazards or turn signals with the headlight switch activated. I am trying to divide and conquer but it is frustrating.

I have tried to research as many thread as I can find but am running out of patience.
Any ideas are welcome!

Thanks!
NAte (IMG:style_emoticons/default/beerchug.gif)

[904svo]

Try this, remove the bulbs from the fog lamps, then try to operate the fog lamp switch with the key on. If this blows the fuse remove the fog light relay and measure the resistance to ground on the white/yellow wire it should be open. If
its grounded you have a short in the wiring some were.

[Zaney]

Alright, I measured the resistance on the fog light wire from the relay to the fog lights and found the short.
So, I ran a new wire and FOG LIGHTS! (IMG:style_emoticons/default/smilie_pokal.gif)

However, when the headlight switch is pulled half or full: (IMG:style_emoticons/default/headbang.gif)

no fuses blown
no fog lights
no hazards
no turn signals
the signal and euro marker lights just stay on solid.

Without the headlight switch pulled everything above works without fail or fault.


I am taking a frustration break and going to reread some previous threads but any pointers are welcome!

Cheers!
Nate (IMG:style_emoticons/default/beerchug.gif)

[914Mels]

Sounds like you've checked you power wires, now look for a bad ground. If you've ever seen a car on the road where the the taillights dim when the brakes lites come on, that's caused by a poor gound. It sounds like your ground will only handle part of the circuit load.

[904svo]

Try this check the voltage on both sides of fuse #10 if voltage is present remove the headlight switch and check the red wire on terminal #30 if power is present you most likely have a bad headlight switch.

[Zaney]

I tested the #10 fuse and I have power on both sides of the fuse. Also, the headlight switch 30 pin red wire has power too so, I am looking for a new switch. Hopefully, this will be the end of my gremlins (for now (IMG:style_emoticons/default/barf.gif) ).

To be continued...

[904svo]

Before you go out and get a headlight switch, try this with the head lights on ( key
must be on) check and see if you have any voltage on fuses 1,2,3-4 with high beams on and off. If not check the combination relay that supplys power for the
high beams and low beam lights. You should hear the relay click as you cycle the
high beams off and on.

[Zaney]

Ok, in testing the last recommendation: I have around 9 volts at the 1-4 fuses with the headlight switch engaged.

Then, with the high/low cycles I found that I can only click to the high beams. Then, I cannot 'click' the turn signal lever to go back to low beams.

Does this mean a bad relay instead of headlight switch?

If so, would the Saab electronic relay be a good upgrade/change?

Thanks for the help!

Cheers!
Nate (IMG:style_emoticons/default/beerchug.gif)

[904svo]

You should have voltage on fuses 1-2 when the high beams are on. When the low
beams are on there should be voltage fuses 3-4 not 1-2 at the same time. If you have voltage on all 4 fuses at the same time, check your ground connections
in the trunk (brown wires) there's one for the left side and right side.

[Zaney]

I checked the grounds in both rear trunk locations and they seem to be Ok.

I did take the turn signal wires (grey/red and grey/black) off of the headlight switch and pulled the knob.(There is power at those terminals w/ switch engaged) With the headlight switch engaged and the two wires removed I have active headlights and turn signals. However, the foglights still do not work with the headlight switch engaged.

So, is it still a ground issue or a short?

I am almost ready to take it to the shop but I would rather learn something.

Thanks!

Nate (IMG:style_emoticons/default/beer3.gif)