Wiring setup for J type O/D

[Mioraet]

Having a problem with electrons going missing in the overdrive setup on my MK2 TC. The Haynes manual shows a rudimentary wiring diagram for the A type overdrive but nothing on the J type. I guess I just assume they are similar? Where do I find the overdrive relay (if my car has one) None of the wires are the right colour either so I'm guessing it has been "fixed" in the past. I want to re-wire it from scratch but I need to know it's meant to be wired..

[Alex]

No relay on a Jtype.

[Clive]

On other triumphs, and indeed my vitesse when fitted with j type saloon box, it ran from the same supply as the reversing light switch. J type only needs about 3A or so, so as Alex points out, no relay required. Would suggest its own fuse though, especially as the wiring gets a lot of abuse and has a nasty habit of wearing through the insulation :(
Also, don't forget to wire in the inhibitor switch!!
Clive

[Alex]

From memory the supply originates under the washer bottle (green wire and a green and yellow? wire).

[Richard B]

J'type the supply comes 'daisy chained' off of the reversing light switch on the gearbox.

Sometimes you need to unbolt the gearbox crossmember to lower the box to give you enough access to the wiring.

[Mioraet]

OK, so from the reverse light switch supply a wire should feed the gear lever switch, then from there to the inhibit switch, and then from inhibit switch straight to the solenoid?

[Richard B]

254 wrote:

OK, so from the reverse light switch supply a wire should feed the gear lever switch, then from there to the inhibit switch, and then from inhibit switch straight to the solenoid?

Yes but, easier to do;

reverse light switch supply a wire should feed the inhibit switch, then from there to the gear lever switch, and then straight to the solenoid

Make sense? and don't forget other side of Solenoid to Earth.

[Mioraet]

Richard_B wrote:

Yes but, easier to do;

reverse light switch supply a wire should feed the inhibit switch, then from there to the gear lever switch, and then straight to the solenoid

Make sense? and don't forget other side of Solenoid to Earth.

Oh dear... the way mine is set up now looks like the gear lever switch is live regardless of lever position, however i get power to the solenoid only in 3rd and 4th, the trouble is this is intermittent at best. I'm about to dive under the car again, but I recall from my last look, there seem to be too many wires. Maybe someone has done a real bodgy job in the past!

[Mioraet]

OK I've unwired it and have narrowed the problem down to 2 possibilities. Excuse the crude artwork but the pic is how it was wired up. The main problem was intermittent dropping out in 4th, it worked fine in 3rd, so I thought the inhibit switch was faulty. I can't replicate the fault with my testlight though, but the other day, the O/D dropped out and there was no power to the solenoid in any condition. There was power to the gear lever switch at all times so I suspect the bullet connector is responsible for this one. Do you think the inhibit switch could still be suspect? If it works fine in 3rd should it work equally well in 4th? Is it just an on/off switch or more complicated than that?

[Richard B]

Quite often it can be a dodgy connection in the Lucar connector or where the Lucar connector goes onto the inhibitor switch.

Are these after market 'crimped' connectors? Bear in mind this is an area that is oily & prone to vibration. Connectivity problems are not un-common. I would go for a soldered Lucar and make sure they are tight on the switch.

Also have you checked the earth wire from the other side of the solenoid?

[Mioraet]

Well it's taken me all day and I've had to jack the car up 3 times and lower the gearbox 3 times (whose idea was it to put the inhibit switch there?!!) but I have won!
At first i rewired the whole lot from the bottom of the gear lever but again it would only work intermittently, so i ripped all the wire out and started again. No joints anywhere, and all terminals soldered and protected with heat shrink and I even threaded new wires down the gear lever which was easier than I thought.
Finally I am overdriven! Now i have a big hole in the exhaust front pipe! Methinks a fracture from lowering the gearbox too much maybe. Sigh.... It never ends :X