Discovered one or two interesting developments with the headlight wiring.

"BiTurbo228 - Dr Frankenstein of Spitfires" (biturbo228) 09/26/2018 at 16:27 • Filed to: Fix It Again Tony

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First off, the PO had wired in a relay to the headlight position switch which in effect changed the function so that the sidelights didn’t come on when the ignition was off. Presumably so you can have the headlights up and the rest of the car off. Fair enough, but it dangles around and hits my knees so that came out.

Second, we discovered that the positive for the dip beam had burnt out previously. No wonder seeing as it’s not relayed at all and the direct power goes through both the headlight switch on the stalk and the position switch. The PO had replaced that with various relays tapped off various wires so that the lights came on with the position switch. Again, fair enough, but we’ll redo it as some of the wire gauges are teeny-tiny for the load they’ll be carrying.

Lastly, we discovered that this relay assortment had been spliced into two relays in the fusebox which don’t appear on any of the wiring diagrams we can find...but are in a photo in the Haynes manual. What the what?! Oh, and half of the wires running to/from this relay appear to have melted. One of these goes to the fog lamp switch. The second output is plugged directly into the trigger feed so once activated it triggers itself. The next one shares a couple of wires (hopefully earths) and seems to go to the wiper switch.

These three revelations took all day to discover. Why? This is why:

W hy so many wires? There’s only a dozen or so electrical systems in the whole car. Why the world’s supply of wiring? At least they’ve got a good array of colours so it’s not a monotone nightmare to trace.

Oh, and if anyone wants to see a narrowly avoided vehicle fire, this is what one looks like:

Melted insulation all up the length of wire to the fog lamp switch which runs through big looms and adjacent to carpet. Also melted insulation on that weird triggers-itself-positive-feed. Current thinking is that the fog lamp system doesn’t have a fuse as standard and there’s a short somewhere further down the line. We’ll see tomorrow I suppose!

Oh, and also nearly managed to brick an £100 fusebox when we went to disconnect the main power in and the spade terminal came out with it! Pulled out of the circuit board within the sealed-ish box. Luckily we were able to carefully pry it open and solder it back on, but that was a tense half-hour or so :S

Isn’t wiring fun? ;)

Just Jeepin' > BiTurbo228 - Dr Frankenstein of Spitfires 09/26/2018 at 16:33

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Wiring is about the only work I’ve done on my Jeep this year. Installing new CB and GMRS radios, trying to identify a short that cropped up after 4 inches of rain when I was driving around topless, replacing a headlight, trying to replace a trailer plug, etc. Always more to do, always too few skills to do it.

farscythe - makin da cawfee! > BiTurbo228 - Dr Frankenstein of Spitfires 09/26/2018 at 16:36

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aaaaaaaaaaaaaah! nightmare fuel cable spider

i hate working on the lectrickerie in a car.... mechanicals make sense to me... lecktrickery is like magic...

RamblinRover Luxury-Yacht > BiTurbo228 - Dr Frankenstein of Spitfires 09/26/2018 at 16:43

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he sidelights didn’t come on when the ignition was off. Presumably so you can have the headlights up and the rest of the car off 

Quite backwards from how I remember my Mk. 1 Golf truck. In its case, the headlights were a risk to drain the battery, but one might need a parking light left on on the car after parking, so the parking lights would stay on and the headlights cut off with the key. Sensible and German, to my way of thinking. In my Mercedes, no such wise precaution because it’s got a chime... or so it should if it weren’t part of the very dodgy light control module and no good anymore. At least the Mercedes has the nice option of selectable left or right side only parking lights. Also rather German.

I’ve got no chime in the big Ford to warn me the lights are on, so I haven’t quite decided whether to rig an aftermarket headlights chime or a relay. The chime appears to be the more accepted or usual thing for a classic Ford. .

TheRealBicycleBuck > BiTurbo228 - Dr Frankenstein of Spitfires 09/26/2018 at 16:45

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“Presumably so you can have the headlights up and the rest of the car off.”

Ah, the smuggler /drug runner edition. The last Fiat Spider I looked at had a similar setup connected to the hazards switch. I guess that’s appropriate. Without the running lights it was a bit of a hazard.

BiTurbo228 - Dr Frankenstein of Spitfires > Just Jeepin' 09/26/2018 at 16:53

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Yeah I've learnt a lot doing this job. Still need to learn how to solder, but beyond that I think I'm good for wiring :)

BiTurbo228 - Dr Frankenstein of Spitfires > farscythe - makin da cawfee! 09/26/2018 at 16:58

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I used to be like that, but when my mate showed me that it’s actually little more that sticking a multimeter places to see what wire connects to what it's lost all its mysticism...

farscythe - makin da cawfee! > BiTurbo228 - Dr Frankenstein of Spitfires 09/26/2018 at 17:00

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lol tbh... i mostly hate it coz im exceptionally gifted at electrocuting myself

seriously... i look at a wire and get a shock

(and in one case a mate of mine thought it’d be funny to start the car whilst i was removing the starter engine... i no longer ask him to help me)

Wrong Wheel Drive (41%) > BiTurbo228 - Dr Frankenstein of Spitfires 09/26/2018 at 17:10

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Ive been wondering if the PO messed with the lighting wiring in my STi. Because the lights are on all of the time no matter what. I cannot turn them off while driving. The only way to actually turn the low beams off is to turn the switch to OFF and set the parking brake. Even still, the DRLs are on so long as the key is set to ON no matter what. I like that I never have to think about turning my lights on, it is rather convenient. But it doesnt seem logical to be that way from the OEM. 

davedave1111 > BiTurbo228 - Dr Frankenstein of Spitfires 09/26/2018 at 17:13

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How much of that is stock eighties Fiat?

Are you sure it’s not quicker and easier to start from scratch and rewire the lot? My guess is you’ll never track down every last problem in that mess. And that you can design a better wiring loom than stock.

lone_liberal > BiTurbo228 - Dr Frankenstein of Spitfires 09/26/2018 at 17:19

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No, no it is not .

BiTurbo228 - Dr Frankenstein of Spitfires > davedave1111 09/26/2018 at 17:19

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This thought passed my mind multiple times through this job. I could definitely do it with half the wiring weight...

BiTurbo228 - Dr Frankenstein of Spitfires > Wrong Wheel Drive (41%) 09/26/2018 at 17:29

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Yeah that sounds screwey, although if they are run off the ignition switch it would come on whenever the ignition switch is on.

BiTurbo228 - Dr Frankenstein of Spitfires > farscythe - makin da cawfee! 09/26/2018 at 17:39

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I find it helps to disconnect the battery before doing this stuff ;)

But yeah, don't get that mate to help ;)

farscythe - makin da cawfee! > BiTurbo228 - Dr Frankenstein of Spitfires 09/26/2018 at 17:43

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lol yeah... thats the other lesson i learnt that day

BiTurbo228 - Dr Frankenstein of Spitfires > TheRealBicycleBuck 09/26/2018 at 18:47

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From what I can gather the electrical system in X1/9s and Spiders is pretty much the same so that might well be the same thing. I do know there’s a ton of wires that go into the back of the hazard switch (more than I’d have guessed were required for a hazard switch).

BiTurbo228 - Dr Frankenstein of Spitfires > RamblinRover Luxury-Yacht 09/26/2018 at 18:55

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Yeah that’s how it’s wired up stock, but it was built as a show car so I reckon he rewired it so you could have the lights up at a show and not drain the battery. I’ve rewired it back to the stock setup. What I’d really like to do is intercept the wire for the popups at some point so that you can have the sidelights on but not the popups up, so in the dawn and dusk you can have running lights that don’t affect your aero. Project for another day though. I’d quite like to drive the thing...

Oh god please not a headlight chime. It’s one of my biggest pet peeves with cars. It’s so damn easy to wire in a relay to provide ignition-switched power to your headlights so they turn off when you turn the key off. Why more manufacturers don’t do it I don’t know. The Alfa does and it’s brilliant.

Never worry about leaving the headlights on again. In the winter I never even switch them off if I’m driving to and from work in the dark.

RamblinRover Luxury-Yacht > BiTurbo228 - Dr Frankenstein of Spitfires 09/26/2018 at 22:03

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The main reason to go for a chime would be that I’m enough if an absent-minded juggins when I do leave them on, it can be many hours before I’m back. Thus leaving the parking lights able to do the deed alone . Either a relay or a chime is quite easy, though, since it uses a floor mounted beam level switch.

Actually, reckon I could do both at the same time getting into the circuit and bin the chime if I ever get annoyed. Or leave a switch on. Or wire it also to the door so it only rings if the door is open, lights are on, *and* key off. Provides juggins protection, but ought to never  hear it in normal course of things.

BiTurbo228 - Dr Frankenstein of Spitfires > RamblinRover Luxury-Yacht 09/27/2018 at 04:55

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Ah yeah parking lights. A chime might work well for them.

Or an entirely different parking lights switch so you can just ignore the headlights and just press a different button on the rare occasions you actually need parking lights...

Highlander-Datsuns are Forever > Wrong Wheel Drive (41%) 09/27/2018 at 16:54

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That’s a subaru thing. All subarus have DRL/low beam on all the time. That’s probably why the lenses on my impreza yellowed in 7 years.

Wrong Wheel Drive (41%) > Highlander-Datsuns are Forever 09/27/2018 at 17:00

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I just can’t comprehend why there is even a switch then. It makes no sense to have an on off switch that the only purpose it ends up serving is to dim/brighten the radio and gauge lighting. I guess in 2006 they didnt want to use a light sensor to control that since it would have cost too much to implement. But it still seems silly that the light switch doesnt change the lights. I always feel bad when I pull up to a guard booth of some sort with a sign that says “DIM LIGHTS” and I want to apologize for my undimmable lights. I have the HID cutoff height adjustment switch which is neat but it doesnt really do enough notches to be all that useful. 

Highlander-Datsuns are Forever > Wrong Wheel Drive (41%) 09/27/2018 at 17:02

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It’s dumb, but the cool thing is when you turn the car off, the lights turn off too. My outback is the same way. I’ve caught myself driving at dusk thinking my lights were on when it was really the DRLs.

Wrong Wheel Drive (41%) > Highlander-Datsuns are Forever 09/27/2018 at 17:08

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Well the DRLs are slightly different though. Those of course are always on but the low beams themselves are what I can’t turn off. I am not sure if the DRL on my car is really a DRL. It is impossible to see that it is on, even in a dark garage. I only have noticed by seeing the reflection in a mirror in the dark. But the HID low beams are always on any time the parking brake is off, regardless of the switch. And I cant imagine replacing HID bulbs is as easy as normal halogens. I know the owners manual says something to the effect of “ONLY REPLACE HID BULBS AT THE DEALERSHIP”. Which I think is balonga since I will DIY everything!

davedave1111 > BiTurbo228 - Dr Frankenstein of Spitfires 10/01/2018 at 05:09

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In all seriousness, given the extent to which you’re already going it might be a lot quicker. You could lay out whole new wiring runs in the time it takes to trace one wire.

BiTurbo228 - Dr Frankenstein of Spitfires > davedave1111 10/01/2018 at 07:51

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Very true. I’ve sorted it now, but it did take quite a bit of sitting there thinking about where the hell these wires could be going to even start tryi ng to trace them...

Cé hé sin > BiTurbo228 - Dr Frankenstein of Spitfires 10/01/2018 at 08:55

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The K12 Micra does that too. Open the door with the lights on and ignition off and the lights silently extinguish themselves. If you want to keep them on you turn them off and on again.