TR2/3/3A Options for TR3 Wiring Harness?

[Lbp]

I'm thinking about re-doing the wiring and investigating options for my newly acquired '57 TR3A. I was wondering if anyone has experience with Advance-Autos PowerBlock wiring harness that uses relays to take the load off most of the switches? Any other suggestions or tips? How about conversion to negative ground?

Bill

 

[TR3driver]

Not a bad setup at all; but I wound up keeping the original harness and just adding the features I wanted. The fan relay came incorporated with the adjustable fan control, so I didn't need that relay in the "Power Block" and I don't have an electric fuel pump, so that relay wasn't needed. The original solenoid on a TR3 draws very little current, so I don't feel a second relay is needed there either.

Then on the headlight wiring, I wanted a circuit breaker for each side (so only one side goes dark if a breaker opens). (Unless it has changed recently, the AAW setup provides no overcurrent protection for the headlights. The early kit I got didn't even have connectors so the front apron could be removed, although I understand the connectors are now 'optional'.) Since relays are cheap, I wound up using a relay for each filament (4 relays in all).

I also dislike Dan's suggestions for how to wire an alternator. My current TR3 is still wearing its original generator, but on the previous TR3A with the 60 amp Ford alternator, I added a shunt to the back of the ammeter, to recalibrate it to roughly 60 amps full scale. I'll do that again if I ever get around to installing an alternator.

Negative ground was a no-brainer for me. Just makes thing so much easier if you ever add electronics (like a stereo, alternator, cell phone outlet, etc).

All just IMO of course, others will no doubt feel differently.

 

[Geo Hahn]

I prefer the look of an original harness -- having the choice of the older lacquer/braided style and the vinyl version I went the the latter as I thought it might be easier (or at least more familiar) to work with.

I added relays and fuses where needed but did not convert to negative ground as that was not needed just yet (and can be easily done later if things change).

Randall's wiring looks good, mine was a disaster -- replacing it was the only option, though I drove 18 years with it like this:

A new harness does a lot for reliability and ease of maintenance.

 

[TR3driver]

Randall's wiring looks good, mine was a disaster

That photo was the 3A after it got wrecked. The current TR3 looks a lot worse, as the cloth colors are simply gone and the cloth itself is falling apart in many places. I also had to patch up some of the indiscretions committed by the previous owner.

But this is definitely not a show car and never will be; I'm much more interested in function than form.

 

[martx-5]

I put in the Advanced Auto Wire harness. It is a project that will take at least a full weekend, probably more like two or three. I'm very happy with the results. The instructions and wiring schematics are very good, as are the materials used, although I bought the kit when when Advance was still owned by Dan Masters. There were some extra items that I had to purchase, such as the plastic corrugated harness wrap that I used and some extra bullets and shrink wrap tubing. It would be best to have a digital multimeter to check things as you go along. I like this kind of work, so it was a lot of fun for me doing this job, even though at times it seems to be in utter chaos...I also located the power block assembly under the bonnet instead of the recommended location inside under the dash.

 

[PeterK]

It looks much easier to re-wire when the car is apart.

My 58 came to me with a new harness which the PO made in all red wire. It's oversized wire so at leat that part is good. Wouldn't recommend all red wire d'oh.

I have a brand new harness from Britishwiring.com sitting in a box waiting to install. Maybe this winter if I can get the shop warm enough this winter.

It look to be a pain no matter how simple it is so I keeping putting it on the back burner.

 

[Geo Hahn]

...Wouldn't recommend all red wire d'oh...

Ever seen one done entirely in lamp cord? At least it's pretty handy for paired connections.

When my TR3A went thru its last resto the body was in the shop for more than a year. Desperate for an occupation I laid out my new harness on the floor in the shape it would assume once in the car and them made my own, very literal, wiring diagram. This forced me to learn and confirm every connection. I also made a cardboard mock-up of the dash to have all those connections ready and the sub-harnesses prepared.

At that time I also tinned the ends of the bare wires (screw connectors on the early 3As).

I spent the equivalent of several weekends fussing over the details -- but when the car returned and reassembly began the installation of the harness took no more than a couple of hours with everything working correctly first time around.

...Maybe this winter if I can get the shop warm enough this winter...

In my case most of the work was done indoors (in front of the fire) so perhaps winter is the ideal time to tackle this.

 

[TR3driver]

Desperate for an occupation I laid out my new harness on the floor in the shape it would assume once in the car and them made my own, very literal, wiring diagram.

I gotta tell you, Geo, I can't quite imagine being in that situation. I have so many irons in the fire that my only problem is which one to pick up first (and the fire going out)! This probably explains a lot as to why your TRs are so beautiful, while mine are perpetual rolling restorations/projects.