Overdrive wiring harness woes

[Jason]

When I pulled the carpets and interior out of the TR the wiring that goes into the gearbox practically fell apart under the dash, the Lucas connectors are pretty corroded. Coupled with the gearbox removal and refit I'm left with a few wires hanging around to reconnect.  No problem I thought, until I came to put it all back together again!
On the gearbox, I've got the overdrive inhibitor /solenoid wire, that's OK but then I have the reversing lights to cope with, again from the gearbox there are two wires coming from the switch,  one green and one green/purple.
Then hanging out of the dash are 5 wires! OK two are black and I'm assuming they are just earths. There's a green, a green / brown and the yellow/green overdrive wire.
I don't know if it's because I've been staring at this too long or I've just lost the plot but I'm baffled. Does anyone have any reference pictures or words of wisdom for me?

[Richard B]

Well, two questins;

Is it a J Type or an A Type?

Does it have a relay fitted?

(or it might be a miss-mash/hodge poidge/ bowl of spagetti!  ;D


J Type (on Saloons, no relay fitted)

Green feed to reversing light switch, other side of swtich (Green/Brown) goes to the  reversing lights.

Green wire taps off of the green feed and goes to the inhibito switch,

Othe side of the inhibitor switch goes to the O/D control switch

Otherside of control switch goes to solenoid and the earth.




A Type  Relay fitted

Two wires go to reversing light switch, green and green/brown

From the relay, one wire goes via the control switch and the 3/4 inhibitor switch to earth to operate the relay.

From the relay, one wire goes to solenoid and then earth (this is the switched feed)

[Richard B]

Does this help?

[Jason]

Sorry Richard, it's a J type - the title of the post is misleading as I think the overdrive wiring is pretty simple now - one wire in from under the dash (the Yellow/Green wire) that goes to the inhibitor switch then to the solenoid and then out of the solenoid as a black wire to earth.
It's actually the other wires that had me stumped because there were too many for my small brain! So it's green from dash to green on box (that leads to the inhibitor switch) then out of the switch it's green/purple and that goes to green/brown under the dash. Am I right in thinking then that if I join the two wires coming out of the dash then the reversing light will come on? That's the Green/Brown and the Green?
I'll go to it fresh today and it will probably make sense!

[Jason]

Richard_B wrote:

Does this help?

Yes, but even enlarged on the printer and with my specs on I can't read it :-(

[Steve AKA vitessesteve]

Those colour wiring diagrams are also available from my website: http://www.vitessesteve.co.uk/Servicemanuals.htm

[Jason]

Thanks Steve that's helpful.

I do wish I could "get" electrickery, it's just one of those things that just passes me by. When it works I understand it but when it doesn't I'm lost!

[Richard B]

Jason wrote:

I do wish I could "get" electrickery, it's just one of those things that just passes me by. When it works I understand it but when it doesn't I'm lost!

Get a mult-meter and work through methodically, one part/problem at a time.

Yes, Green and Green/Brown should be reversing lights, put them together with the ignition on and see  if they come on.

Presumably you can do your testing of the wiring with the PI inhibitor switched and the coil disconnected?

If you get stuck I can come over at the W/E or in an evening. What year is your car? Where is the O/D switch, on the steering column or the gearstick?

[ferny]

Richard_B wrote:

Get a mult-meter and work through methodically, one part/problem at a time.

That's good advice. But if you don't want to buy one I've found licking the ends of the wires just as effective. ;)

[Jason]

Thanks Richard, I think I've got it now - it always helps if your reversing light earths are not crap - once found and fixed it all works as it should although I will have to remake all the connections. This car's previous owner seemed to lick Scotch Locks, I hate them and have been on a witch hunt for them in every car I've had.

I do also have two lights on under the dash that seem to be always on and they are now controlled by the door switches! Another thing to investigate I think.

Now I have the basic wiring sorted I'll fix all the connections and put it back together enough for an extended test drive as I can't hear the overdrive clicking in.

I've been testing with the pump off and coil disconnected as you say - far safer!

The was made in December '72.


Ferny licking things - it's an image I don't want in my head!

[Nick Jones]

Jason wrote:

Ferny licking things - it's an image I don't want in my head!

I tend to agree..... though the terminals of a fresh 9v battery might be amusing  :P  Electric fence is probably a bit unkind?

Just think of the wires as pipes, with the body of the car as the great big earth "tank" at the end.

Nick

[Saltddirk]

Ah,
and here i am thinking it was Smoke, not water running through the wires/pipes.. :)