So, electrics might not be witchcraft after all...

"BiTurbo228 - Dr Frankenstein of Spitfires" (biturbo228)
09/20/2018 at 19:43 • Filed to: Fix It Again Tony

Well, there has been progress with the exxy. Turns out I wasn’t quite as nearly done as I’d hoped...

Couldn’t get the brakes to bleed properly, but managed to find a set of Montecarlo 38mm calipers. Same design including the handbrake, just a bigger piston. Rebuilt them, fitted and still won’t bleed. Read somewhere you might need to have the handbrake cables loose for them to bleed properly. I’ll try that next.

While it was outside I thought I’d have a go at fixing the alternator. Replaced the junky old wire from alternator to starter, and thought I’d take a positive feed to make a relay for the starter solenoid as about about half the time it wouldn’t engage (not enough juice unless the battery was freshly charged).

Old and busted/new hotness:

Original solenoid wire now triggers a relay which takes power straight from the positive post on the starter rather than potting power straight through the ignition switch (terrible idea).

Worked beautifully! Starter engages every time, and spins quicker too. Perfect...except that it wouldn’t start now.

Oh.

Bit of troubleshooting and it would seem that the ignition ECU and coil weren’t getting power. After lots of chasing the loom around and trying to puzzle out gow the PO had spliced together the X1/9 and Uno Turbo looms we discovered that he’d powered both the ignition coil and ECU through the old dinky ignition coil wire. Really didn’t like the idea of having the power for an old and expensive Italian ECU come directly from a noisy coil.

The answer? Fusebox and more relays!

So we’ve got a positive feed from the starter going to a fusebox, with separate relays for the coil, ignition ECU and fuel system tachometric relay triggered by the old ignition coil wire, and the aforementioned starter relay.

Works a treat!

Now I’ve just got the same thing to do with the headlights which have started blowing fuses and have a similarly confusing wiring setup...

At this rate I might get an MoT this month!

DISCUSSION (31)

lone_liberal > BiTurbo228 - Dr Frankenstein of Spitfires
09/20/2018 at 19:56

Nicely done! I hate dealing with old wiring so much I ripped all of it out and replaced all of it with a new harness. It was a pain, but not nearly as much a dealing with 50 year old wiring that had been hacked at. Of course it might be slightly easier finding a new wiring harness for an American pony car than an X 1/9.

BiTurbo228 - Dr Frankenstein of Spitfires > lone_liberal
09/20/2018 at 20:10

Yeah I came pretty close a couple of times. I was only really stopped by the fact that there’s so much wiring in an X1/9. Honestly, I don’t know how they managed to pack so much wire into a car that only has lights, popups, and electric windows.

I can’t wait until I wire up my Spitfire. It’s going to be so simple and neat.

One fusebox at the back next to the battery for all of the electrics at the rear (all relayed off the ignition switch). One fusebox at the front for all the electrics there, taking power from the positive post on the starter. One big fat cable and maybe two triggering wires from the ignition heading fore-aft. No metres and metres of cable for no real reason. Tachometric relay running the fuel pumps instead of one of those inertia cutoff switches that kill the car if you hit the curbs on the ‘ring. Discrete looms for each system wrapped together and then cable tied to other discreet looms if they head in the same direction (no chasing a fuel setup through one single clumped together loom if I want to change to EFI ).

Yeah. it’s going to be really nice to work with :)

arl > BiTurbo228 - Dr Frankenstein of Spitfires
09/20/2018 at 20:41

Good work!

Wiring is not my thing and I truly admire people who can understand it and fix it.

Distraxi's idea of perfection is a Jagroen > BiTurbo228 - Dr Frankenstein of Spitfires
09/20/2018 at 20:47

When the headlights started blowing fuses on my X1/9, it turned out to be a diode in the wiring harness down by the headlight, FWIW. Fixed it by soldering in a random diode from an electro ni cs shop.

Future Heap Owner > BiTurbo228 - Dr Frankenstein of Spitfires
09/20/2018 at 21:23

Mmm, that wiring looks good!

I am scared of seriously investigating the giant bundle of wires and relays in the footwell of my truck, s ince one of them is a Hella lights relay and it seems to have a wiring harness from a different model year(?!) .

Akio Ohtori - RIP Oppo > BiTurbo228 - Dr Frankenstein of Spitfires
09/20/2018 at 22:51

Do you have flex hoses and if so have you replaced them? When I first got the Saab I couldn't bleed the rear brakes. Turns our the flex hoses had degraded in such a way that they wouldn't allow fluid through.

BiTurbo228 - Dr Frankenstein of Spitfires > Akio Ohtori - RIP Oppo
09/21/2018 at 04:33

It’s got braided hoses on the back. Not new, but not old either. It’s definitely letting fluid through, but there’s bubbles each time I go back to it. No visible leaks of fluid either.

If the handbrake cables thing doesn't work I'll see if there's any leaks in the hidden bits of brake pipe.

BiTurbo228 - Dr Frankenstein of Spitfires > Future Heap Owner
09/21/2018 at 04:36

Thanks :)

And yeah wiring harnesses that are different from the wiring diagram sounds vaguely terrifying. We’d be lost without the wiring diagrams for the Fiat.

That reminds me actually. Must do a diagram for the bits I've changed. It's pretty straight forwards, but I'll probably still forget!

BiTurbo228 - Dr Frankenstein of Spitfires > Distraxi's idea of perfection is a Jagroen
09/21/2018 at 04:37

Thanks for the tip :) I'll definitely investigate that once we've made sense of the changes the PO has made :S

BiTurbo228 - Dr Frankenstein of Spitfires > arl
09/21/2018 at 04:42

Thanks :)

Wiring really isn’t my thing either, but it’s really not as hard or complicated as I’d thought.

Making your own wiring is pretty straight forwards and quite satisfying too :)

Chasing down wiring problems isn’t as nasty as I’d thought either, it just takes a bit of time. All you really need is a multimeter and to methodically check the connections from the start of the circuit to the end.

Lots of info to hold in your head while you’re doing it, but you can always write it down in a little diagram as you go :)

tl;dr I didn't understand wiring either, but it turns out it's not as witchcrafty to deal with as I thought :)

davedave1111 > BiTurbo228 - Dr Frankenstein of Spitfires
09/21/2018 at 05:24

Electrical fault finding is a simple enough process. But it’s incredibly annoying if you can’t find a wire you’re following .

It’s odd, though. If I pull out a multimeter and check a circuit for continuity or something, people look at me like I’ve done some kind of magic.

davedave1111 > BiTurbo228 - Dr Frankenstein of Spitfires
09/21/2018 at 05:30

With the brakes, have a look at the master cylinder - seals etc. - if you continue to have trouble. If you have bubbles coming through to both sides, it’s unlikely to be the slave end that’s leaking.

( IME new rubbers are no guarantee of anything on cars as old as ours , if they happen to be undisclosed new old-stock where the rubb er has lost elasticity they can blow out the first time you press the pedal. If you’re really unlucky it’ll be a leak too small to see easily. )

Akio Ohtori - RIP Oppo > BiTurbo228 - Dr Frankenstein of Spitfires
09/21/2018 at 08:57

Ahh OK gotcha. I also had that problem once... no idea what I did to solve it. Possibly just ignored it haha. I want to say it was a loose bleeder hose or the nipple was letting air in or something silly. Either way, good luck!

Tareim - V8 powered > BiTurbo228 - Dr Frankenstein of Spitfires
09/21/2018 at 10:46

At this rate I might get an MoT this month!

is it not MOT exempt by now?

BiTurbo228 - Dr Frankenstein of Spitfires > Tareim - V8 powered
09/21/2018 at 17:15

Nah that’s only pre-1960. This is an ‘87 so relatively late on in X1/9 production. Lqte enough in fact that the Haynes wiring diagram doesn’t quite match the actual car (joy of joys...)

BiTurbo228 - Dr Frankenstein of Spitfires > Akio Ohtori - RIP Oppo
09/21/2018 at 17:20

Yeah already gone through the ‘bleed nipples not done up tight enough’ rodeo :S

BiTurbo228 - Dr Frankenstein of Spitfires > davedave1111
09/21/2018 at 17:30

Yeah we’ve got that now with the headlight setup. Not only has the PO hacked about splicing wires, but it’s got two mystery relays that don’t appear on any wiring diagrams. Yay.

And yeah I was part of the ‘multimeters are wizard-equipment’ crew until about 3 days ago when it all sort of clicked :)

BiTurbo228 - Dr Frankenstein of Spitfires > davedave1111
09/21/2018 at 17:38

Yeah replaced the master cylinder and it’s not showing any leaks. Resealed all the calipers too and they seem dry too. There’s a couple of splitter blocks too which also seem dry.

I'm hoping the handbrake cables sort it as otherwise I'm pretty stumped :S

Tareim - V8 powered > BiTurbo228 - Dr Frankenstein of Spitfires
09/22/2018 at 01:45

Its a rolling 40 year now (so up to ‘78) , but didn’t realise the x1/9 was that recent

BiTurbo228 - Dr Frankenstein of Spitfires > Tareim - V8 powered
09/22/2018 at 07:02

Ah that’s tax exemption. I thought MoT exemption was only pre-60.

And yeah the early X1/9s make it into tax exemption (‘77 of ‘76, I can’t remember when the first came out). They made them for ages though. They made them until 1989, meaning you could have cross-shopped a brand new X1/9 against a brand new MX-5!

Tareim - V8 powered > BiTurbo228 - Dr Frankenstein of Spitfires
09/22/2018 at 14:36

MOT exemption is now on the same rolling year basis as tax (new law came into play may ‘ 18)

BiTurbo228 - Dr Frankenstein of Spitfires > Tareim - V8 powered
09/22/2018 at 17:28

So you're right! Managed to miss that. Awesome :)

davedave1111 > BiTurbo228 - Dr Frankenstein of Spitfires
09/26/2018 at 16:57

My dad still uses his old analogue multimeter from the 70s(?) that’s the size of a shoebox, and probably way more accurate than our shitty modern digital ones. I borrowed that once or twice before I had my own, and if regular ones are wizard-equipment, that’s full on bubbling-test-tubes mad scientist.

The dial has a parallax mirror and everything - but try to explain to people why you’re carefully lining up a sight and they really will think you’re mad.

Then again the only time I can remember measuring anything except circuit continuity since leaving school was to check resistance across a misfiring injector. Oh, and I’ve checked the voltage of random batteries found in the back of drawers.

It’s kind of depressing they give us pointy hats for this stuff. But encouraging that at least they don’t burn us for witchcraft anymore.

davedave1111 > BiTurbo228 - Dr Frankenstein of Spitfires
09/26/2018 at 17:08

It must be in the bits in common if it’s both sides - is it affecting the rears as well?

I have no real idea how, but when the F’s clutch slave cylinder was leaking, it was sucking in air without leaking fluid noticeably. That kind of leak is somewhat annoying to track down through inspection , but obvious enough when you think it through.

Talking of the F, that reminds me, I was looking in a box the other day and found two zero-loss valves. Do you still want one? I’m assuming if you’d paid me for it already I’d have heard complaints by now :)

BiTurbo228 - Dr Frankenstein of Spitfires > davedave1111
09/26/2018 at 17:12

Awesome. I wa nt one!

I think I checked the resistance of a water temp sensor as it heated up once. The rest has been continuity checking.

I wonder if that's what the head wizzards with their degrees do as well...

BiTurbo228 - Dr Frankenstein of Spitfires > davedave1111
09/26/2018 at 17:36

Oh yeah that’d be great! Let me know the payment details ;)

And yeah it might be something like that. It’s certainly not visibly le aking, but it still feels spongy. Plan is to drive it for a bit and see if it's pads, or if it fails its MoT get the garage to give it a bleed :)

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

I should really try and get out in the F for a longer run while the weather’s still not too bad. We could try and meet up somewhere?

BiTurbo228 - Dr Frankenstein of Spitfires > davedave1111
10/01/2018 at 07:20

Sounds good to me :) I’m pretty all-in at the moment getting the Spit painted before the weather turns, but I’m definitely up for that :)

davedave1111 > BiTurbo228 - Dr Frankenstein of Spitfires
10/01/2018 at 10:22

What are the chances you’ll be anywhere north of the river any time soon? Or if you’re going to be in central London that’s easy enough.

Otherwise, there are some nice driving roads down your way from what I remember. How far are you from the south end of the Woolwich Ferry? Obvs no fun trip involves the Dartford crossing...

BiTurbo228 - Dr Frankenstein of Spitfires > davedave1111
10/02/2018 at 06:33

Not any time I know about yet, but I’ll let you know if I am :)

I’m about halfway between London and Brighton. Something at Goodwood of Brands Hatch maybe would probably be a neat thing to meet up for :)

davedave1111 > BiTurbo228 - Dr Frankenstein of Spitfires
10/05/2018 at 09:11

I have a vague recollection we’ve got to this point before, and that’s why I still have your valve :)

Are you anywhere near a Thameslink station? There’s some interesting stuff round that area on Easycarclub :)