Fuse box layout help

[oregonmon]

While trying to switch the wires to run fog light only, yeah I know silly, I must have moved something wrong because now my brights will not come on.
What did I do wrong here. Notice 7 does not have wires at the top.

[oregonmon]

Uploaded another photo, first one was the wrong side.

[oregonmon]

[BlueWing]

Off the top of my head on position 5 you have a gray wire and I think it should be empty as the hi/low headlight positions are bussed behind the fuse block. Was that a wire you added?
If that is the case maybe your sending 12 volts to that position.

Hope that helps.

Terry

[oregonmon]

Thanks.
I didn't add any wires but I don't remember which ones I moved.

[BlueWing]

I don't know if this will help but this is a pic of my 79SC fuse panel. I know somewhere I have better details as I was messing around with mine and always try to document before and after. So if you need Ii can look further.



Terry

[oregonmon]

Yeah I have a grey wire in number 5 and 7 is empty on top. According to Bentley 5 is low beam right, I took the wire out if the top and lo beams still worked but still no hi beam.
By bluewings photo there's no other fuse without wire on top. But my 20 and 15 do not have a top wire. I've also got 3 more relays than yours. ??

[BlueWing]

i'm still working on some wires a PO player with. He added a radio circuit and fog lamps. I have a no option car so the only relays I had were fuel pump and horn. Last week I added two relay sockets for headlight control and added the 3 position fuse block to fuse the wires returning from my dimmer switch,added protection. My dimmer switch would smoke if I used the headlight flasher so i knew I needed to add the relays for the headlights.

Here is the kicker, from testing and trying the system out when I finished up I have high beams only. After scratching my head and retracing all my work it turns out my dimmer switch gave up it's ghost and failed. I also have a failed steering column bearing so when that arrives this week off with the wheel and repair the bearing and switch, covered well here in my searches. So be certain your dimmer switch is still ok.

On the fuse block position 5/6 and position 6 has the white wire from the dimmer stalk are bussed under the fuse block on top with fuses to the yellow (pos. 5) and green/yellow (pos. 6) on the bottom for the high beams.

Position 7/8 has a yellow wire on top from the dimmer stalk in position 8 and is bussed under the fuse block with fuses to the white/blue and blue wires on the bottom for the low beams.

You can remove the yellow and white wires one at a time, secure safely so not to short and read 12 volts with the dimmer stalk in their respective positions.

Terry



Terry

[ossiblue]

One thing to remember is that wires entering from the top are feeding current to the fuse block from a switch, the battery, a relay or some other source. They may even be wires (like at the top of fuse 5) that are receiving power from the buss in back of the block. The wires at the top are not affected by removal of the fuses. Wires from the bottom are load wires carrying current to a device and are affected by the fuses. Not having wires at the top of some terminals may not be important because (a) your car does not have a particular device to activate, or (b) the fuse is bussed behind the block to an adjacent fuse, as mentioned by BlueWing.

As far as your problem goes, I'd also suspect the stalk switch or the dimmer relay as well as the connector under the dash for the high beams. You will need to do a little sleuthing to track down the problem. From your photo, your light wiring looks correct but it would help if you could let us know exactly what fuses/wires you were moving around.

BTW, according to the schematic: Fuse 6 is yellow wire and is bussed with fuse 5. Yellow and yellow/green leave fuses 5 and 6 and feed the low beams.

Fuse 7 is a white wire, is bussed with 8. Blue and blue/white leave fuses 7 and 8 at the bottom and are high beam.

The white wire at the top of fuse 7 might be your first stop to see if power is there when you activate the switch on the stalk.

[Canada Kev]

While I can't help with your problem of getting your headlights to work they way they're supposed to, I may be able to help with running your fogs only.

I have my fogs set up to be able to turn on at any time that the ignition switch is on. Some have managed to move some wires about on the fuse panel to be able to run their fogs without the headlights being on, but I wasn't able to replicate their success.

I did this by simply moving the fog light relay trigger wire (grey one) from terminal #56 of the headlight switch (headlamp circuit) to pin #75 which is hot at any time the ignition switch is on. All this wire does is energize the fog light relay so that it will operate with the fog light switch on your dash. It carries no current for the actual fog lights.

There are some thoughts here on running fog lights independent of head lights. And a matrix of what all the terminals on the headlight switch do and when they do it: fog lamps operation

[Wil Ferch]

There are lots of problems here.....

First....because it's the most dangerous...Terry....you have NO 5A fuses at all in your fuse block. Danger !.....there are a number of locations where an 8A (white) fuse is shown where there should be a 5A ( yellow). Maybe you did this....maybe the PO did this.....doesn't matter, but fix this. I know the yellows are HARD to find....and some say 8 is only 3A more.....but you have to look at this as being 60% more than 5A.

As to proper wiring, most all Porsches 74-89 are *basically* alike in the major portion of the fuse block. There are some insulation-color conventions that also doesn't make sense by the Original Poster. YELLOW feed wire ( fuse panel TOP) is typically low beam, not high beam. Fuse position # 6 as you count from the front of the car ( *typically*), is feed to low-beam. Position #6 and #5 are internally-bridged on the feed-side. WHITE wire is typically power feed to high-beams. Typically enters top at position # 7. Positions #7 and #8 are internally-bridged on the feed side.

I am also attaching 3 attachments that may help visualize this, with detail on the fog light wiring. The last attachment is from the factory manual how to add fog lights for cars that never had them. The third attachment, para 7....tells you how to attach the grey wire for fogs. The reason there is a difference for US cars is US law requires fogs to be "on" only when low-beams are "on". When wired this way as sugested for US...the fogs also drop out when hi-beam is activated. I would suggest instead to wire per the instructions for the Euro cars. It allows independent operation of the fogs whenever you want to....regardless if low/high beams are on or off. Disregard some of the hand-written notations on this sheet as some of it is wrong.

[BlueWing]

Will, thanks for the heads up, your 100% on the white versus yellow current percentage. I do have at least 2 yellow (very pale) fuses there I believe are for my city lights but I am going to do a full inventory of the whole mess. I was in there lately to remedy a smoking dimmer stalk. When I first got the cat I must have removed 8 lbs. of wires from the Ungo box and other unterminated ones, still have 2 that are not hooked up and I need to find the other ends. I am also removing a fog light system the PO installed. I might have my high/low confused as I'm going from memory and my old pic.

Thanks for the input and I'm saving your attachments for further reference.

Terry

[Wil Ferch]

No problem.... hate to see wiring fires..... seen enough of that....so I'm sorry if I come off less than Emily Post etiquette on this topic. Like to see us guys get it correct if we can....

The attachments should be enlargable once captured.

For reference:

Blue= 25A
red= 16A
white= 8A
yellow= 5A

BTW...if we use the factory arrangement for 79 model year....the Tech/Spec Porsche books says it follows exactly my fuse convention I show for the 85 in my first attachment. Reading front-of-car....to back....and saying front-most is #1--->

1-foglites 16A
2-license plate lites 5A
3- fr/rr parking lites right ... 5A
4- fr/rr parking lites, left...5A
5- low beam ,rt...8A
6-low beam, left...8A
7- hi beam, rt...8A
8- hi beam , left..8A
9- fr turn signal, rt...5A
10-fr turn signal left...5A
11-l/r stop lights, flasher relay, backups...16A
12- rear defog relay,blower, rear defog indicator lamp.. 25A
13-windhield wiper/ washer ...25A
14- sunroof, rear wiper...16A
15-Aux heater, cig lighter, blower switch indicator lamp...16A
16-power windows..25A
17-emergency flasher...16A
18- interior lite, clock, glove box lite, trunk lite...5A
19- headlight cleaners, etc...25A ( 16A in 76, 16A in 78, 25A in 83, 25A in 85).. ????
20- A/C, A/C blowers, P/S...... 25A
21- P/W, sunroof, seat htr, 25A ( 16A for 76, "fuel pump" ?...???)

[oregonmon]

Thanks Will,
Voltage tester shows no power on high beam fuses at 7&8.
This sucks. A buyer is coming to pick up this car tomorrow morning and is driving it from Portland to LA. I really don't want him not to have hi beams.

[oregonmon]

Another pic of the whole panel.

[oregonmon]

Should there be a wire feeding into the top of 7 from the right?

[Wil Ferch]

Oregonmon:

Look at the schematic....first link....I show in post reply #11 above.
White incoming power gets fed to postion #7....and we know #7 and # 8 are "bridged" or bussed from behind or internally. So,....this incoming power is split to feed fuse positions 7 and 8....each being the high beam power for each of the 2 headlights. The incoming wire can just as correctly ( wiring-wise) be attached to #8, and not #7...since they are linked or bridged from behind.

I'll attach a photo of my previous 85. Notice it too shows incoming white ( white "band" on blue wire...since I was using the headlight relay kit that used blue wire insulation for both hi/lo)....on fuse position #8, instead of 7. That's the way I found my unmolested 85 with the original incoming white wire.... and that's how I re-used that position as I added headlight relays.

[Wil Ferch]

Whatever grey wire you have on top of positon #5 is being fed by #6 incoming power next door. I notice I have no wire on top of #5.

[oregonmon]

So I tried moving the grey wire from 5 to 2 because I see yours has two grey wires on top of 2.
Before, when I went to turn brights on both headlights and fog lights went off. What this did was when I went to turn brights on the headlights went off again but the fog lights stayed on. So that is even more wrong. He!
I'm not getting power to my hi beams, we know that much but why?
Thanks Wil for all your feedback.

[ossiblue]

Originally Posted by oregonmon

So I tried moving the grey wire from 5 to 2 because I see yours has two grey wires on top of 2.
Before, when I went to turn brights on both headlights and fog lights went off. What this did was when I went to turn brights on the headlights went off again but the fog lights stayed on. So that is even more wrong. He!
I'm not getting power to my hi beams, we know that much but why?
Thanks Wil for all your feedback.

If you're getting no power to the hi beams (white wire at top of fuse block), you need to trace back its source--the dimmer switch on the stalk and the connector under the dash.

The behavior of your fog lights and headlight was correct before you moved the grey wire. The low beams and fog lights would go out when the switch to the highs is activated (U.S. wiring.) Your stalk switch is working to the point where it breaks the circuit for the low beam/fogs but you cannot be certain it is completing the circuit for the high beams.