5th & now 6th (🙈) MX5 & the beginnings of a Rocketeer build

[RichardFX]

Curious that the nice new “Negative” terminal in the second picture has both P and + symbols.

If it fits correctly with the right inside curve shape making snug contact over the whole surface, then not a problem.
But it’s strange all the same. Is there another P and + on the Positive terminal?

In the last picture, those are relatively low current wires.
Stick a pin into the wire close to the white block and measure the resistance between pin and the ground tag, or even the bolt head which usually makes excellent chassis connection via all the thread contact area.
There should be no difference between this reading and the reading you get with just the test meter probes shorted (usually about 0.5 Ohm)

[Roadster_Robbie]

I’d do as @999to5 says and buy some pre-made earth cables with ring terminals from Halfords and run a new earth cable from the battery to the existing body ground. Has that battery earth terminal not got a nut and bolt?

[Fivealive]

Thanks @RichardFX @Roadster_Robbie @999to5

I was hoping I could so something as below, using these ring terminals:

So run standard terminal from battery to ground, ending in ring terminal, then put another ring terminal on top of that joined to the main battery wire going to the PPF. Would that work?

[Fivealive]

[Roadster_Robbie]

I think that your concept is good (don’t connect the battery positive to the PPF though). If you can make good crimps with what you have then fine. I’d still use pre-made stuff though.

[Fivealive]

Ok, so I spent a couple of hours out there fiddling around with my earth points.

I checked the PPF earth and whilst the bolt areas was ‘OK’, the exposed copper looked like this:

Looks like burning to me.

So, with some hope that i’d found the culprit, I used a spare and brand new set of jump cables to make an extra length of wire to act as a new earth wire from the PPF to battery ground to battery.

Any exposed copper you can see was covered up afterwards with some self adhesive fabric tape.

Unfortunately, the car still did not crank, however I did notice that the temperature gauge now doesn’t move at all, when previously when I turned to on, the temp gauge would move from zero to halfway. I’m guessing that thats a good thing! So it seems like the new earth cable has solved one issue but not the issue of cranking. I guess tomorrow i’ll move forwards to the starter and alternator.

The further I go with it still not working, the more I worry this is far more serious and i’ve buggered the ECU (again) or something.

[Fivealive]

And another question is:

When I got it back from Rocketeer it started, albeit after lonnnnnnnnnnnnnng cranking.

But now it won’t crank at all even with a more powerful and definitely working battery.

So, does that sound like an earthing issue or something else?

Also - I just read on another forum the classic give the starter a whack a couple of times with a rubber mallet advice - is that worth trying?!

[RichardFX]

Good idea, but…

Those particular rings are a bit on the thin side, almost weedy. They will be the highest spot resistances on that cable. Consider how much the cross-sectional area of conductor has been reduced, and compare them with that excellent original terminal. The original cable also kept the strands going through without a join.

I would consider soldering those two rings together to improve the pass-through connection, before crimping them onto the cable.

Better.
If you can find some rings of a heavier, thicker gauge metal, comparable with the original, and with more width in the ring annulus, that would be worthwhile. Crimping with the correct crimp-pliers is the best way to make the connection secure.

Don’t be tempted into soldering the stranded cable into the crimp using a gas torch or soldering iron, it’s usually a bad idea for various reasons. Although it can be OK if done properly, ie quickly, with bright shiny clean fresh metal surfaces and using only just enough flux and an appropriate safe solder-pot.

The good old garage solder-pot.
This takes me back to my student days when we were fixing Mk2 Jags, Mk2 Zodiacs and PADx Crestas. These starter cables were always breaking strands at the solenoid end because of stress fracture where the sharp edge of the crimp terminal bit into the copper of the cable. (Bad design)

We found some copper pipe usually sold for heating (microbore?) which happened to be the right size internally. Stuck a drill shank in where the cable would be soldered to hold the shape, flattened an inch after that in a vice, and drilled the right size hole for the terminal bolt. Also drilled a small breather hole in the wedge shape where the end of the cable would be.

Paint it and the copper of the cable with the flux, squeeze it onto the cable enough not to drop off, and dip it in the solder pot long enough for the solder to run into it, you could see the level change a fraction. Take it out before the insulation began to melt or the solder wicked up too far into the supposedly flexible cable.

[999to5]

The guy who sells rhe cables for Ducatis gets them manufactured by a specialist company who mainly produce cables for the railway industry.
The terminals are heavy gauge copper crimped onto high quality cable with serious pressure.
There is a lot of current going through those cables and you want the resistance to be as low as possible if you are not going to produce excess heat.
With cheap properly engineered cables readily available, Im not sure why you’d want to try and make your own.
As for the non-cranking, it is a bit of a worry that it wont turn at all

[Fivealive]

Thanks @RichardFX and @999to5 - I totally agree regarding the proper cabling - this wasn’t meant to be a permanent solution, it was just for testing purposes whilst I had the materials available.

Does anyone know where the rear right trunk earth is? it’s listed on the diagram that @carl_s shared above but I can’t see one in my trunk in that position, only the one between the rear light bulbs.

Hope you’re having a good long weekend - thanks again for all the help, it is much appreciated - more than maybe you can imagine

[Roadster_Robbie]

I think that you’re back to basics here now. Have you got a permanent 12 volts at the starter motor (thick wire) and a switched 12 volts (thin wire) when turning the key to the start position?

[Fivealive]

Hi all, what a palava. Or as a friend (more of an aquaintance) once said, “what a pavlova”.

So, as @Roadster_Robbie suggested, I went out and checked my voltages.

12.92 at the battery, 12.92 at the starter.

I then - for no reason whatsoever - randomly tried to start it and fiddled around with the key in the ignition, 2 to start to 2 to start to 2 to start etc and then I heard an almost inperceivable crank sound. I then did it again and it fired second crank.

A couple of my neightbours were there, one works for Red Bull F1 and one has a history of tinkering on Landrovers. Between us we reckon that either the solenoid isn’t pulling back far enough to let the engine crank or I have an ignition switch issue.

I then took a look at my key:

Are those ‘cracks’ normal? I’m guessing not, so i’m going to replace my ignition barrel and keys as much for piece of mind as anything.

With the Rocketeer build, starter motor is an engine out job and I haven’t got the mental frame of mind at the moment to do that unless I really have to, so i’m going to try that first.

Thanks for all the suggestions and help!

[Benji93]

That cable looks corroded to me not burnt bit definitely worth swapping

[Benji93]

Get a new key cut asap before that snaps in the barrel

An engine out for the starter motor is woeful, but I’d be looking at your ignition side of things of you played with it and it got life, new barrels with keys are cheap and easy

[Fivealive]

Thanks @Benji93 - thats the plan.

I’ve already replaced the corroded/burnt out cable with a temporary solution.

I’m going to get some brand new battery cables ordered and probably get a brand new gen mazda barrel.

[carl_s]

@Fivealive

Does anyone know where the rear right trunk earth is? it’s listed on the diagram that @carl_s shared above but I can’t see one in my trunk in that position,

I think this earth is the main one from the battery to the body, that then carries on to the ppf. It’s the first 10” or so of the main battery earth cable

The starter apparently can be changed without taking engine out. I have been assured by some other owners

[Fivealive]

Thanks @carl_s

It keeps on starting, Very weird.

[carl_s]

This is the one:

[Fivealive]

Hello everyone, I hope you are well.

Sorry for the radio silence, i’ve been working 70 hour weeks and my health hasn’t been great…there’s probably some correlation there!

Anyway, quite a lot of progress has been made, so here goes.

Ground problems.

I’ve had ground problems for the entire length of this project so I set about changing everything.

I started from the battery and worked my way forwards. I stripped back the wiring at the battery and the PPF, not ideal - the PPF actually looked like it has burnt somewhat but it might be an illusion.

I took a wire brush to the grounding points and changed the connectors.

Unfortunately, this didn’t actually make any difference. But, it was good to know that the grounds were in tip top condition.

Starter Issues

As you’ll remember I was getting clicking but no cranking. I ordered a UV Joint socket extension to that I could fully detach the starter and gave it a wobble, then refitted it. It made a different noise! I went back and left it slightly loose, and result - it did what a starter should do!

Crank problems

This is a weird one and technically still ongoing. Once the starter started working, I assume i’d be home and dry (idiot) - as the car had always atrted before once it had cranked. Alas, no:

The weird thing about this is, the battery was 100% full (and a new higher cranking battery too), the ground issues clearly weren’t there. It took about ten attempts of the cranking above to even get a splutter, so it could mean some kind of newly developed fuel pressure issue somewhere.

Alternator squealing

After I eventually got it started, it made a hell of a noise so had to set about adjusting my alternator position, which is always fun! The kit comes with an adjustment bar, so once youve got the bolts in the correct position, the adjustment is actually pretty straightforward.

Interior

The interior is coming together now, after many reincarnations. I settled on the tillett B5, which is now fitted in the car along with new carpets. I’ve also had a go at some ‘retrimming’ myself and covered the door tops in alcantara. I’ve got a Momo gearstick to match my steering wheel, changed the tombstone for the extended JASS version and changed the air ■■■■■ as mine were a bit crusty. Anyway, possibly not to everyones taste but I like how it’s looking at last!

Exterior

I’ve changed the headlights for some crystal units and the sidelights for some sequential items from ILM. I’m not sure wherther i’ll keep them or not, but i’m leaning towards keep!

Hope you’re all keeping well!

Andrew

[Fivealive]

Hi all,
We’re almost at MOT time!

The only thnig that stands in my way is my reverse light which is stuck on.

When I turn my ignition to on, my reverse light comes on regardless of whether my car is in neutral or any gear.

It was working totally fine and it hasn’t been on the road.

I removed the switch connectors and reconnected
The switch on the gearbox is brand new.

It’s almost as though the live feed is now running directly to the reverse light rather than it being switched.

has anyone got any ideas? I’ve searched and the usual suggestions are a broken switch or a short, neiher of which are the case here.

So frustrating!