TR4/4A TR4 overdrive relay position

[Adrio]

Now that I have the mechanical and electrical part of my "new" overdrive worked out for my TR4A, I have a question. Where is the overdrive relay suppose to be located. I am looking in "obvious" places trying to find holes that match the relay mounting holes but no luck.

 

[Alan_Myers]

Hi Adrio,

The relay mounts on the cockpit side of the firewall, just above and to the right of the gearbox cover. It's sort of, but not exactly on the internal side opposite the starter solenoid mounting point. You should find one or two short, unused studs there. I'm guessing without looking that they are #8 or #10 NF threaded.

The wiring comes out through an approx. 1/2" diameter hole in the gearbox cover, near the front and slightly off center to the right. I imagine there was a rubber grommet in that hole to protect the wiring and that it just sort of snakes out from under the gearbox's carpet cover up near the firewall.

Have fun!

Alan Myers
San Jose, Calif.
'62 TR4 CT17602L

 

[Adrio]

Thanks Alan. I will look for the spot. My gear box cover does not have the hole in it (yet) as it is a new poly one I got.

I am torn between making a wire loom for this and installing it with a temporary switch while I wait to find a used (or buy new) and get delivered switch or just waiting and doing it once when I have all the parts. I only have two more months of driving this summer so I am leaning towards the temporary option as it gets the car back on the road sooner.

 

[Alan_Myers]

Hi again Adrio,

I bought the wiring harness that goes from gearbox/OD to the relay. It's not expensive and I wanted the properly color-coded wires. On the other hand, it wouldn't be hard to make one up if you had the bullet connectors. I added a couple clamps to secure the wiring on top of the gearbox.

I think the steering column switch wiring is already present as a part of the main harness. However, I really can't confirm this since I'm using a custom switch and wiring (in the shift knob).

Alan Myers
San Jose, Calif.
'62 TR4 CT17602L