TR6 Need Help on 71 TR6 Overdrive Wiring

[hondo402000]

I have an A type over drive transmission going in when my engine gets back, I am in the process of replacing the front wiring harness and I am trying to figure out how to wire the OD, the challenge is in the wiring diagram for a 71 TR6, in the optional overdrive box in the corner of the diagram shows and says a N(brown wire) W(white wire) from fuse box. the question is where do they plug in to the fuse box. Would they plug in to the same locations of current White and Brown wires? I know they are both provide power to the OD circuit, the white looks like it engergises the relay coil and the brown wire pulls the solonoid in(which pulls more amps)

any help would be appreciate(Wayne)

Hondo

 

[angelfj1]

I have an A type over drive transmission going in when my engine gets back, I am in the process of replacing the front wiring harness and I am trying to figure out how to wire the OD, the challenge is in the wiring diagram for a 71 TR6, in the optional overdrive box in the corner of the diagram shows and says a N(brown wire) W(white wire) from fuse box. the question is where do they plug in to the fuse box. Would they plug in to the same locations of current White and Brown wires? I know they are both provide power to the OD circuit, the white looks like it engergises the relay coil and the brown wire pulls the solonoid in(which pulls more amps)

any help would be appreciate(Wayne)

Hondo

Hondo: The simplest approach - solid brown - un-switched and un-fused. Connection points are your fuse box and ammeter. White is ignition - un-fused and switched by ign switch, you can tap at fus ebox or back of ign. switch.

Be sure to say 'hey' to all of my TCC friends (the old f-arts) who might remember me - founding member #4.

good luck

 

[hondo402000]

Thanks, that helps

Hondo

 

[TR3driver]

I suggest adding a fuse to at least the brown wire.

The solenoid used on the A-type OD has two internal coils, a pull-in coil and a holding coil. The pull-in coil draws close to 20 amps, but is supposed to operate for only a fraction of a second each time the solenoid is engaged. Normally when the plunger hits bottom, it presses an internal rod that opens some contacts hidden under the end cap, taking the pull-in coil out of the circuit.

If for some reason that doesn't happen, like the solenoid is misadjusted, or the lower stop falls out, or even a piece of rock finds it's way inside the solenoid; the pull-in coil will quickly burn up and ruin the whole solenoid. Replacements were not cheap, last time I looked. I have also once had the little plastic pushrod break, which would have been easy to replace if the coil wasn't burned up.

But with the in-line fuse, instead of the solenoid burning up, it will just pop a 50 cent fuse.

I use a MDL-8 (8 amp, slo-blo) just because I've got a box of them. But I believe an ordinary fast blow 5 amp (eg AGC-5) will work as well.

 

[simpson]

Wiring: I think the OD switching goes thru a proper relay by the fuse box, as well.

 

[HerronScott]

Hondo,

Not sure about the TR6 but for the TR4A I thought that the connections for the relay were already in the harness and you just needed to buy/find an overdrive subharness?

Scott

 

[hondo402000]

Scott
the OD switch on the column plugs into the separate OD harness 2 wires go to the fuse box and the rest go to the switches on the transmission. So nope on the TR6 its totally separate

Hondo

 

[DNK]

Hondo, There is no relay for the A type overdrive?

 

[sail]

The Quantum installation kit for the A type has a relay: Quantum kit
but you don't want my advice wiring it.

 

[HerronScott]

Hondo,

Not sure if this helps but this was posted on vtr.org regarding the electrical wiring for installing an overdrive.

" Next I mounted the overdrive relay. Since my car already had two relays (horn and hazard flasher), I put the o/d relay next to them (on the sidewall next to the wiper motor). The wiring diagram in the Bentley manual is good here, except that it just shows both the brown and white wire going to the fuse box, without telling you where to connect them. The brown wire goes to a fuse box terminal that is always hot, while the white wire attaches to a switched fuse terminal only hot when ignition is ON). "

There's more here on the rest of the electrical connections as well (no pictures unfortunately).

VTR TR6 A-type overdrive installation

I did find this picture showing the overdrive relay and horn relay mounted but that doesn't really help you with the connections on the fuse box.

Scott