electronic speedo drive into a 1990 Mk2 mechanical drive?

[Bev]

Hi There everyone!
I'm just wondering if it's possible to wire in an electronic speedo drive into my mechanically driven speedo mk2.

I'd obviously have to take my cluster out and remove the speedo and put the new electronic one in. From what I can see from the Mk2 wiring guide I'd need to do nothing in my engine bay other than removing the old drive cables, fitting the electronic sender, then putting the plug on. The rest of the wiring looks like it's in the boot.

However, what else would I have to do on the car side of the wiring to get this to work? My mechanical drive is really starting to piss me off :rant:. The needle is getting jumpy. Plus, my car is on 17" wheels so the speedos reading under what I'm actually doing, and I'd loooooove to be able to use one of these to adjust my speedo.... :)
http://www.jaycar.co.nz/productView.asp?ID=KC5435&CATID=&keywords=speedo&SPECIAL=&form=KEYWORD&ProdCodeOnly=&Keyword1=&Keyword2=&pageNumber=&priceMin=&priceMax=&SUBCATID=

P.S. If any of you poms want one of those, me or anyone in auz could probably post it to ya for cost plus postage. Looks like a pretty handy gizmo. ;) Jaycar is an Aussie and Kiwi diy electronics store. They've got some pretty useful stuff.

Bevan

[OlberJ]

Think Woodsy did this very recently, he'll be able to tell you exactly.

[robwsurf]

cant you just get a later dash to work with the electronic drive yes that box will work to alter that i have a simillar one to try and get s2000 dash working in mine

[Bev]

yeah, I can get the later dash easy as can be. It's the car loom side of the wiring that has me a tad worried....

Bev

[Paul Woods]

yes i just did this for the first time the other day,in fact the way i did it was a bit of a first.

It was,however,not simple.... the electronic speedo unit will not fit inside the rev1 mechanical clock housing,so i had to cut the back of the clocks away very carefuly from the rest of it to leave a big square hole for the electronic board to recess into.

Now there were various bits i had to trim and adjust to get this to fit,it took around 4 hours in total but i finally managed to get the electronic speedo head into the rev1 clocks.

Next problem is wiring,the rev1 body harness will not have any of the elctronic speedo wiring in it,you will be able to plug your v6 speedo plug in to the electronic drive and that will leave you with a pink and a light green wire in the boot (earth and signal wire respectively).The power wire to the electronic speedo in the gearbox is already present.

You need to earth the pink wire and to get the light green signal wire forward to the dash you need to run a wire from the boot to dash or just steal an unused wire in the loom.

Now all you need to do is supply the electronic speedo head with three signal wires,forget the multiplugs,you need to put ring terminals on three wires and join them straight to the speedo board.They are earth,12v ign,and the signal wire from the rear.You can trace the circuit board on your rev2/3 clocks to find out which pins are which.The fourth pin on the board is signal out,the purple/white wire that usually feeds the ecu,we dont need this to go to the rear anymore,but you will need to feed this terminal to the purple/white wire on the clock plug,this will keep your power steering working.

In all it works,you end up with an electronic drive in the box and an electronic speedo head thats standalone from the rest of the clocks.The other way to do it is to fit the complete rev2/3 clocks into a rev1,this has been done before but it requires a repin of the 3 clock plugs,you have got to know exactly which pins go where to do this,pretty easy if you have both diagrams at hand.

Hope that helps!

[Marksman]

What do you think the fit would be like in the MK1 clocks Paul?

[Paul Woods]

good question...probably a no go but somebody needs to have a play with that idea.... a mk1 without a speedo cable is speedo utopia!

[Marksman]

That it would be :thumbsup:

Anyone got a MK2 rev2 or higher speedo or instrument cluster lying around? :pray:

Wouldn't mind having a look at this myself if so...

Cheers,

Owen.

[Paul Woods]

Wiring it in is a doddle owen,so all thats needed is a good physical fit.

[Marksman]

Sounds promising, I seem to remember Jimi giving some info on unused wires running from the front of the car to the rear so easy to sort that bit too by the sounds of it. If it works well I'll supply a mounting bracket / adaptor thingy. Might solve an age old problem. Could possibly combine it with a V6 rev-counter conversion for those who need both...

Just need the clock now, oh and a sender too methinks. Anyone?

Owen.

[Paul Woods]

Which car is it going into owen? or rather which tranny?

As for unused wires,you just need to use power and earth already behind the clocks,and then use the purple/white speed signal wire that runs from rear to front if its a v6 mk1 as its not used.

[Marksman]

Not sure which car, will have to pick one! Paff and I are sorted with mech drives on our tubby boxes and lyn has a mech drive for her MK2 NA on V6 conversion, but if it helps the members we could convert any of those to electric to get the ball rolling. Probably start with Paff's as that's running rather well now.

Cheers for the wiring info :thumbsup:

Owen.

[Bev]

Thanks for that Paul! I'm definately going to give this a shot. Do you know of any spare wires running from the boot to the cluster in the gen1 MK2? How about this unused purple/white that you talk of? I take it this used to feed the ECU for speed cut? Would certainly save me a fair bit of time rather than having to run a completely new wire all the way forward.

First things first though, I need to sort out my brand new, but leaking rear main oil seal. Of all seals, why that one?!?! WAAAaa...... Out comes the engine again. New oil, new coolant, new gearbox fluid.... more $$..... I really don't feel like trying to remove the box with the enigne still in.

Bevan

[Marksman]

If all the fluids are recent why not drain them into clean containers and reuse?

Owen.

[Bev]

Yeah, I guess I could. I've never done something like that before though. Safe enough you reakon?

[Marksman]

Providing nothing has gone wrong with the engine (like headgasket failure where coolant has mixed with oil) and you use clean, dry containers with good seals (2 l plastic coke bottles are good for example) then sure not a problem :thumbsup:

Owen.

[Bev]

Sweet! Got a full recycle bin around with me being a coke-a-holic. I'll give it a shot. No doubt I'll still make a huge fookn mess with coolant and oil everytwhere though.

[Marksman]

It wouldn't be any fun if you didn't!

Owen.

[Paul Woods]

Bev id just remove the gearbox in situ,its easier than you think and its a load more work to remove the whole engine.

As for using the purple/white wire to run the signal forward to the dash.... its normally used to run the speed signal from the clocks back to the ecu for the speed limiter,but it also branches off at the dash to go to your power steering ecu.Now if your car doesn't have PS then i dont see any reason why you can't use this wire to run your new signal through,but if it does have PS then im not sure what the actual differences are between the gearbox generated signal and the clock generated one.If they are the same then no problem,but id suspect not.... why would toyota run the signal all the way forward then return it all the way back to the ecu if they could just pick it up from the gearbox? They must be different.

Short answer is if you don't have PS then use it,but if in any doubt just run a fresh wire because you will never know 100% if a loom wire branches off somewhere naughty.

[Bev]

Rats. I've got power steering I'm affraid. That's a fair point about running it all the way forward, just to double it back. Guess it's time to run another wire then if it comes to it.

As for removing my gearbox off my 3vz, what's the easiest way to drop the heavy bastered down (and get it back in there for that matter? Any ideas? I'd love to not have to drain my coolant. Would save me one hell of a headache. So far I've done the conversion with just a set of 3 ton axle stands and a boot jack.... I've got an engine crane too if it'll help.

Bevan

[Bev]

Actually, I might just drop my engine again. I wouldn't mind installing a walbro while I'm at it and I hear it makes it a hell of alot easier. Only extras to unhook that I can think of are the fuel, coolant, throttle and electrical. Plus, it allows me to put another lower timing cover on. I accidentally dropped a 1/4" ratchet down the front end of the motor when I was pissin around with my timing belt cover bolts with my engine running. Being the idiot that I am, it went down onto the alternator belt/ ac belt, and got fired onto the timing belt cover and took a fricken big chunk out of it, which kinda pissed me off. :(

Bevan