Hilux 4x4 Forum

How do I wire my tach into my system? The guy who owned my monster before me decided to rip apart all the wiring, and it isnt wired into anything. The wiring from the tach leads to no where, and there are no loose wires running off the motor.

HELP!!

aftermarket or OMe tack

Its the ome tach. It has two wire running off of the dash/speedo/tach loom that do not attach to anything and I am assuming that these are the wires for the tach. It does get power because when I turn the key it jumps ever so slightly. This is before I actually crank the motor.

One goes to the negative on the dizzy.

Where would the other go? How do I know which is the neg on the dizzy? I have a multimeter, just dont ask me how to use it!!

Limey

This is a section of the wiring diagram from the standard wiring. I would assume a OME would be wired the same. The right colour of the wire would be black with the Tach (no 27) connected to the Coil (no 4) and the Dissy (no 5). As far as I can see it is only a negative wire that connects it all.

Someone please correct me if I'm wrong.

Ok, just been scanning around - coming off the dash loom (and here I am assuming its for the tach) are two wires (with a connector) one wire is green with a yellow thin stripe and the other is a white with a thin black stripe...

And I cant find my damn coil!! Am I being dumb or what?!?

Ok, ignore all I said about the 2 wires - just pulled the dash apart, and those 2 wires dont do much.
Anyway, the guy who had the vehicle before me shredded the wiring, and if I could just find where the coil is, then I can take it from there. AND I HAVE NO DAMN IDEA WHERE THE COIL IS!!!

Which distributor do you have, the old mechanical one or the newer Electronic one, which has a built-in coil?

Can you post a photo of the relevant part of the engine?

-F_D

Going to take a pic. will be back in 10 minutes!

Here is the offending bit....

Heres the engine bay

Oh Shucks you have the electronic ignition with the incorporated coil as Eric Mentioned. He will have to tell us where to pick up the signal for the rev counter.

If you look at the back of your instrument cluster you will see that the rev counter has 3 screws where the terminals of the rev counter connects to the tracks on that plastic board with the tracks. If you trace the tracks you would be able to see which one of these 3 is the common earth between the different gauges and lights etc. (if everything is still connected and not broken that is) You can use a multimeter to test continuity between (zero ohm) on the resistance setting the vehicle body and these 3 pins to find the earth(according to Scooters diagram it may be marked pin 26).

You say that if you switch on the ignition there is movement on the gauges. So next select the V(dc) setting on your multimeter and measure which pin has 12-14volt on it when you turn on the ignition (according to Scooters diagram it may be marked 4 pin 28).

The remaining terminal (most probably the middle on maybe marked 27) would then be the signal wire which needs to sense the pulses from your dizzy/coil. Mine was also the middle so I ran a wire straight from it to my coil as the existing wire got "lost" during the engine conversion when they wired in my EFI. I also added an extra earth wire onto mine as mine was going dead intermittently and that seemed to sort out my problem.

You have the electronic ignition, not quite electronic, but "pointsless".

Here is a photo of mine:



If I remember, there were only two wires going to my distributor, as can be seen in the front (one red, can't see the other colour clearly, hopefully black). According to the schematic posted by Scooter. The "Pick Up Coil" would be my guess, but this is a guess only. Perhaps try test that first with a small test lamp, in order to eliminate possible damage while slow-idling the motor. If this is the correct point, the globe should flicker. Be difficult to see this, so if the globe does not quite reach full brightness, I would guess we're on the right track.
Use only a small 12v instrument type globe for the tester, or you could buy a nice tester complete at Midas or AutoZone for about R20 or so.

Not very helpful, I'm afraid.

-F_D

Well if the Dizzy only have 2 wires it can only be the 12V mains feed to the coil (should be the red one :? ) and the other would then be the signal wire for the rev counter. This unit will earth through its metal base that sits in the motor. So test to see which wire goes positive (12-14volt/ or lamp going on) when the ignition is switched on, that will mean the other wire would be the signal wire.

The signal wire may not switch the test lamp on if it switches negatively (to ground) as I suspect it does. You may need to put the other wire of the test lamp on the positive terminal of the battery and not the negative.

Eric if the ignition system uses points to sense engine rotation and position it is a mechanical ignition and if it uses a pick-up coil which drives an igniter chip do the sensing and fire the coil it is an electronic ignition. It might be basic but it is electronic.

Eric if the ignition system uses points to sense engine rotation and position it is a mechanical ignition and if it uses a pick-up coil which drives an igniter chip do the sensing and fire the coil it is an electronic ignition. It might be basic but it is electronic.

True... but about as electronic as the old days when I used a Crystal set with a Cat's Whisker to tune in to the local radio stations Also "electronic" rather than mechanical, but hardly complimentary to the refined electronics of today!


-F_D

So I think I've come to the conclusion that:
A) I wont be able to use the tach on my "pointless, anti-electronic" dizzy ;)
B) That I actually need a new dash/speedo/tach unit.

Anyone think its possible to use a newer model dash in a really OLD Hilux??

Thanks for all the answers guys...

No Limey why do you say that? The second wire on your dizzy as described above should provide the pulses to drive your Tach.

So it would be a case of having 12V+ from your ignition (so that it switches on and off with your key) to the pin 28 on the tach, having a earth wire connected to pin 26 and the ire from the dizzy running to pin 27.

Ok, so I tried the light and I got a full bright light, no flickering. Perhaps it flickers at such a rate that it seems to be solid.... the light does come on when touching to positive....
So anyone got any ideas now?

You seem to have the same coil setup that I have; I have just gone and looked again at mine. There are only two wires leading in/out of the dizzy. It's difficult to trace them because of everything else that's in the way but you can see the two wires in the photo I pasted. It appears there is a red wire, and a black one. The sketch above indicates a black wire leading to the tach.

Try this: Take a normal pin and by 'pricking' through the insulation, connect this black wire wire hanging from the distributor to to the (black?) wire from the tachometer. The other wire from the Tacho should (presumably??) go to switched positive from the battery.

If that doesn't work, then I'm at a loss

-F_D

Hi all...

Just a follow up - I sorted it out - wired the tach direct to battery and to dizzy - works fine... sorted out the wiring, and now its running fine.

Thanks for the help all!!

Limey wrote:Hi all...

Just a follow up - I sorted it out - wired the tach direct to battery and to dizzy - works fine... sorted out the wiring, and now its running fine.

Thanks for the help all!!

Liimey

If you wire it directly to the battery it will drain the battery if the vehicle stand for a while. It should be powerd via the ignition switch so that it switches off with the key. If your power wire run straight to the battery you can move it over to the red wire on the dizzy as this will also switch off with the key and then you do not have to strip the dash again 8) 8)

Glad you came right

Good thinking Bennie!!! Will do that right now....

Now I need to sort out my fuel guage.... need a new one - any ideas on where to look and how much?

Limey wrote: ↑Sun Sep 16, 2007 6:15 pm Good thinking Bennie!!! Will do that right now....

Now I need to sort out my fuel guage.... need a new one - any ideas on where to look and how much?

did your fuel guage previously stay where it was when switched of or did it go down to zero,mine yesterday when switched of stayed at just above half.Iremoved it put little q20 and worked the needle up and down.At first it was quite stiff but the movement is now quite smoother but it still does the same

It's normal for the fuel gauge to remain in its position when the ignition is turned off