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.

Any suggestions are very welcome!

Thanks!

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.

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.

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?

Where and how should I trace any issues backwards?

Any help is greatly appriciated

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.

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

Nate

PS

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

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.

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

NAte

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

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.

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!

However, when the headlight switch is pulled half or full:

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

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.

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.

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 ).

To be continued...

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.

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

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.

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

Do the headlights work on low beams and high beams? The fog light only work with the low beams light on.

The fog lights do not work with the head light switch engaged fully. Fogs come on with parking lights (first click) but not High or Low beam

Check the wiring on your light switch sound like it wired wrong. Or the blue/white
wires are not connected to fuse #1. Also check that the red/white wire is connected to terminal #56 on the head light switch, this supplys power to the head lights and only works if the switch is pull out all the way.

Just went out and checked. Everything is wired correctly on the switch and Fuse #1. I used this thread to follow my wiring with PP schematic. ( I caught the mix up with the pic 58L and 15 swapped)

I also have the euro marker kit in the front markers too, that might be an issue?

Thanks!

Nate

Check the following on the light switch
58L should be 2 Gray/black wires
15 should be Red + Red/white wires
30 should be Red wire.

I am at a loss...
Those pins on the headlight switch are correctly connected. I am running out of ideas. I would like to at least get the turn signals to work when the lights are turned on. Fogs are secondary at this point.

Still, ideas are more than welcome!

Thanks!

Nate

Lets start from scratch, forget ever thing before.
Turn the key on.
Turn on your headights do they raise up?
and do the headlights light on low beam and high beam?

Sounds good!

Key on, head lights on and up. Low and high beams work. I did have to clean the relay because the turn signal lever would only engages it 7 out of 10 times. Now, it is fairly consistent.

So whats not working now?

I do not have turn signals or four-way hazards when the headlight switch is engaged (either position)

I do not have fog lights when the headlight switch is engaged to the low beam position (making sure the head lights are not on high beam) Fogs do work with parking lights (headlight switch in first position)

The never ending thread continues...

Ok, now I have solved the Fog Light issue but the only glitch that remains is:

LIGHTS OFF /KEY OFF - turn signals hold solid(euro normal setting), fogs off, 4 ways flash normally.

LIGHTS OFF / KEY ON - turn signals work normally, fogs work (with Mod), and 4-ways work

LIGHTS ON / KEY ON- turn signals flash very slowly and the turn markers are lit up with turn signal cancelled, 4 ways do not flash, fogs work normally.

I am using the PELICAN schematic for a 1974.
Wiring has been double checked against schematic and multimeter used to ensure continuity.

Question on schematic, E19 parking light switch (GY/RD and GY/BK coming from E3 headlight switch)

Where is the parking light switch physically in the car?

I have repaired the ground connection under the dash to ensure proper circuits but I am leaning toward a problem elsewhere?? In engine compartment or in rear trunk with rear lights?

Thanks in advance!
Nate

Can you post a photo of the backside of your fusepanel showing the wiring connections?

I am using the Engman upgrade panel FYI far left wire is a yellow replacement wire to FOG LIGHTS on fuse 1.

Click to view attachment

Let me know if this clear enough

Nate

Click to view attachment

Here is the other side

Arg!
Now,as I am bundling the wiring to be more organized I am popping #10 fuse, when turning on the FOG Lights.

Would that occur if the spades possibly brush another when connected to the headlight switch? Grounding out? If so, would a little electrical tape around the bare metal spades help?

With a week old new baby in the house my Brain is kinda mush. So, any wisdom is much appreciated.

Thanks!
Nate

First the yellow wire which you say is connected to fuse #1 is wrong. that should go to the white/yellow on the fog light relay terminal #87. It sounds like some body
try to wire the fog lights so they work on either low or high beams and screw up the wiring.

I guess I should have clarified myself at bit. The Yellow Wire on fuse 1 was the white/blue wire that goes from fuse 1 to relay J5 terminal #86.

So, I made a new original marking wire from old suby harness.

Now, the white/blue wire connects FUSE 1 to relay J5 at terminal #86.

Click to view attachment
I am using an aftermarket relay for the FOGS due to the original relay falling apart.

Click to view attachment

Click to view attachment

Here is the configuration for the replacement relay:
#30 red/black from J5(FOG RELAY) to FUSE 10
#85 grey/red from J5 to K on fog light switch
#86 white/blue from J5 to FUSE 1
#87 orange (replacing damaged white/yellow) from J5 to Fog Lights

Result= NO FOGS

I am appreciative of all the help!

Nate

Good News!!!

I resolved the issues with the FOG LIGHTS not working - NEW RELAY!

The marker lights staying on and slow blinkers was resolved by: checking all the bulbs. Found that the front turn signal bulbs were single pole rather than the duel pole bulbs needed!

I love simple fixes!!!

Thank you for all who have replied to this thread and offered their expertise!!

CHEERS!!

Nate