View Full Version : TR2/3/3A Winter Project-Wiring Harness

10-23-2013, 09:49 AM
I think I am going to yank all the wiring and electrical and replace it this winter - 59 TR3. Any suggestions on which harness to buy? Also, any recommendations on a nearby therapist to talk me out of this?

Also, since I'll have the dash off, what was the factory treatment for the dashboard?

10-23-2013, 11:45 AM
I am interested to see which harness you select. Seems to me that with the ability to use LED type bulbs and the grounding requiresments etc. there might be better options available than the traditional cloth or vinyl with just the basics but more than likely you'll be installing a seperate wire for the ground.

I was told that a good method to use when removing the wires is to use tabs to mark the wires as they are being removed and to lay the old harness adjacent to the new one to mark the new wires. The system is to use three tabs; one is put on the wire being removed, the second is used on the location it was removed from and the third is attached to the new wire harness, lay the new nest to the old and put the tabs on.... Does that make sense? It was further recommended to install the wires to the gauges through the dash and re install the dash afterwards. I think the dash is painted with "crinkle" paint, mine is black matching the interior color of the car.

I am looking forward to reading what the expert advise as I am going to be doing this soon unfortunately I did not get this advise prior to removing my wires from my car when I began the restoration 20 years ago...

10-23-2013, 02:06 PM
I did mine with a factory harness many years ago. I didn't mark anything prior to removal, at least that I recall. The lay of the harness and the color codes on the diagram got things nicely into place and, as I recall, it only took a couple of days. Note that there are a couple of sub harnesses, one for the trafficator through the steering column and for the lights and horns for example. I don't know if they have to be ordered separately with the new reproduction harnesses.
All the later cars had the black crinkle finish on the center dash section. Early ones were the same vinyl or leather as the rest of the dash.

10-23-2013, 06:04 PM
No computer ribbon cables, no multi pin connectors, TR3 harness is a piece of cake! The biggest set of connections is at the dash cluster. Pull your cluster out, cut the harness at the connections so you can remove the original harness and still tell what color the connections are and then start at the front of the car and disconnect, and then re- connect matching the wires color. It's a pretty simple process with these cars. Try the Roadster Factory sale. They have "correct " harness' at good prices. I have put two harness's in and I can tell you it was easier..............and a whole lot cheaper........than the engine harness I just had to replace in my wifes Acura!

10-24-2013, 08:30 AM
The other alternative if you're not into having the car bone stock is to install the harness offered by Advance Auto Wire. His harness uses multiple relays and fuses along with higher ampacity wiring. It's a lot more work installing it, but I feel it was worth the effort. Besides that, I like doing that kind of work.