Let there be light!

"BiTurbo228 - Dr Frankenstein of Spitfires" (biturbo228)
10/01/2018 at 07:34 • Filed to: Fix It Again Tony

Managed to suss it out. Apparently on later UK X1/9s Fiat added a fog light system using two relays that don’t appear on any other wiring diagrams. These relays fit inbetween the headlight popup switch and the column switch with wires that traipse all the way from one side of the car to the other and back again. The first relay is just used to trigger the second and power the foglight switch (through some dinky little wires which is why they were melted). The second relay powers the headlights through a resistor (again, on the opposite side of the car and back again) so you get dim bulbs for your foglights when the lights aren’t on.

Here’s the wiring diagram that doesn’t appear anywhere else on the web:

That did mean that we had two free relay sockets and a fuse holder within the factory fusebox to repurpose to allow a relayed feed for the dip beams and a relayed feed for the foglight (you only need the rear one and a warning light for the MoT).

A bit of cutting and crimping and here’s what we came up with:

Oh, and here’s the wiring diagram for the starting and ECUs:

Now if only the clutch slave hadn’t just let go we’d be getting somewhere!

DISCUSSION (15)

pip bip - choose Corrour > BiTurbo228 - Dr Frankenstein of Spitfires
10/01/2018 at 07:44

you’ll sort it o ut one day

BvdV - The Dutch Engineer > BiTurbo228 - Dr Frankenstein of Spitfires
10/01/2018 at 07:57

Looks like Tony spend a long time designing the most complicated headlight system possible ;p

BiTurbo228 - Dr Frankenstein of Spitfires > pip bip - choose Corrour
10/01/2018 at 07:58

Yeah it’s really fighting me at the moment. I’ve actually replaced the clutch slave, but it won’t bleed so we’re suspecting the master cylinder now (makes sense give it’s the same vintage as all the rest of the hydraulics which have given up the ghost).

I’ve ordered one so we should be able to test that theory soon :)

BiTurbo228 - Dr Frankenstein of Spitfires > BvdV - The Dutch Engineer
10/01/2018 at 08:02

Yep. Very odd. I think the original wiring layout was pretty damn good for the era. The whole headlight popup setup is really quite smart, using a bunch of interconnected relays as sort of a mechanical computer to trigger various bits and pieces.

The foglight setup feels like a bit of an afterthought compared to that. Probably because it was, given that it was a new requirement very late on in the product cycle. I bet they gave the job to the new guy ;)

Oh, congrats on your thesis by the way. Don’t think I’ve mentioned it :)

Manwich - now Keto-Friendly > BiTurbo228 - Dr Frankenstein of Spitfires
10/01/2018 at 08:03

“ I’ve ordered one so we should be able to test that theory soon :)”

Who’s ‘we’? Isnt it just you working on it?

Wait a second... this car is starting to cause you to lose your mind, eh? You know... about your friend Tony who suddenly appeared. .. HE’S NOT REAL!!!

/jk

pip bip - choose Corrour > BiTurbo228 - Dr Frankenstein of Spitfires
10/01/2018 at 08:05

makes sense, when the clutch slave in my car shat itself years ago ended up replacing the clutch master cylinder one week later.

BiTurbo228 - Dr Frankenstein of Spitfires > pip bip - choose Corrour
10/01/2018 at 08:07

Yeah I read somewhere that if you replace the brake master you should do the clutch at the same time while everything’s out.

Really should have done that...

BiTurbo228 - Dr Frankenstein of Spitfires > Manwich - now Keto-Friendly
10/01/2018 at 08:14

Haha, the royal ‘we’ ;)

Or at least, that's what I tell the labcoats when they come asking questions...

BvdV - The Dutch Engineer > BiTurbo228 - Dr Frankenstein of Spitfires
10/01/2018 at 08:15

That does sound pretty smart!

It does sound very afterthought like, but then again you never know with Fiats :p

Thanks ! I have a interesting job interview planned for tomorrow (a job which actually has a really good connection to my master thesis topic , which is rather surprising ) , so I’m curious what the result of that will be.

davedave1111 > BiTurbo228 - Dr Frankenstein of Spitfires
10/01/2018 at 10:27

There are various bits of software that can do circuit-diagrams easily for you. Bit neater, and a lo t less faff than drawing it all out by hand.

BiTurbo228 - Dr Frankenstein of Spitfires > davedave1111
10/02/2018 at 06:36

Yeah I tried one and it bugged me (you couldn’t get the lines straight j us t by dragging it around). I do need to find one that works as I think I made about 10 of these things before I got one that lined up right and I didn’t make a mistake on.

Either that or start it in pencil...

BlurpleToyotaDishwasher > BiTurbo228 - Dr Frankenstein of Spitfires
10/02/2018 at 15:06

That’s the first picture of it I’ve seen since the repair, it looks a fantastic job - if I hadn’t seen the ‘before’ I wouldn’t have realised it had been done at all .

BiTurbo228 - Dr Frankenstein of Spitfires > BlurpleToyotaDishwasher
10/03/2018 at 16:12

Oh awesome :) yeah it’s worked out really well. You can still see some dents and dings, and if you look under the skin it’s obviously been repaired, but from 5 feet it looks brilliant :)

Closer even if you thought someone else had dinged the wings ;)

facw > BiTurbo228 - Dr Frankenstein of Spitfires
03/03/2019 at 12:53

BiTurbo to the white courtesy phone please: My wife is a killer; X1/9 advice needed

BiTurbo228 - Dr Frankenstein of Spitfires > facw
03/05/2019 at 09:25

Haha thanks ;) I’ll weigh in!