• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

Wiring Harness Installation TR 3

Share this page

Tinkerman

Tinkerman

Darth Vader
Offline
I'm about ready to start the installation of my wiring harness. I have a new British Wiring Inc. harness, wiring diagrams, one color coded. My problem is physicaly where do all the branches go?

Has anyone done this and taken a bunch of pictures of what they did? If someone did and has some pics I would really appreciate you posting them or emailing them to me.

Thanks, Tinkerman

tinkerman@charter.net
 
I just did the harness on my TR3 not too long ago and it was a lot easier than I thought it would. Lay out the harness in the apporoxament location and strech out the branches to the proper location the harness will be a little stiff. All went together fairly easy the only problen that I had is where the harness goes thru the firewall . Two people will make that part easier. I also did all the wiring of the guages before I installed them in the dash. I fed the harness thru the dash. That saved a lot of time and agony from laying on your back and twisting to do the connections behind the dash. Also if you see other photos of a TR you can use them as referance.
Dan
IMG_9486.jpg
.photobucket
IMG_9463.jpg
.com/albums/pp94/tinman1958/IMG_9459.jpg[/IMG]sh!
 
Pulling out the dash and gauge panel and installing it on the workbench is a great idea. I am going to do a wiring harness installation for a friend of mine and that tip is priceless. Thanks, Bill C. Mesa,Az
 
Don, will you kindly post about grounding blocks on new
wire harnesses?

Packing for our move to Leadville, CO. Gonna take
up prospecting for silver mines. I might run a Faro
table or two as well.

d
 
I did a cardboard mock-up of the center panel to locate all the bits and connections, made the installation of that area dead simple.

wiring3.JPG


Also -- I laid the new harness out (in the shape of the car) and made my own diagram directly from it. This was a sure-fire check that everythings was correct (it was) and got me familiar with every connection. I tinned the end of each lead (pre-TS60000 with screw connectors, not Lucar).

I was so well prepped (had several months wait for the painting to complete) that the install took just an afternoon and everything worked the first time.
 
I think you guys are making this way harder than it really is. The switches and lamps can all be wired up (and tested) with the panel entirely removed, as they all install from the back. Then the electric gauges can be wired (and the switches/lamps installed) with the panel still several inches away from the dash. Then you install the panel, choke cable, temperature gauge and (last but very important) connect the oil pressure line to the gauge. Pop the speedo & tach lamps into place while you're under there, and you're done.

BTW, Geo, the in-line fuse holder (found only on later cars but a good retrofit to earlier ones) is supposed to clip to the bottom edge under the switch. Looks to me like yours is too short.

IMO, the factory was dreadfully stingy with ground wires. I don't know that actual ground blocks are required (I don't have any), but I do recommend adding ground wires for the fuel gauge (on a TR2-3) and all the rear lamps. For my rear lamps, I made up a single wire that attached to a fuel tank bolt, and then visited each lamp in turn. They all have the connectors for a ground wire, but the factory relied on the screws into the body to provide grounds.
 
:iagree:
I installed a new harness on a TR3 a number of years ago. It was one of those jobs that turned out to be easier than I had expected. I had labelled the old harness before I removed it, so I had that as a reference. However, the simple wiring diagram in the Haynes workshop manual was good enough to sort it all out (apart from the windscreen wiper motor that was different from the diagram).
As has already been recommended, start at the bulkhead, lay the harness out roughly where it needs to go - tail lights, dip switch, dash board, fues box, wiper motor and horns. Then as you wire up each component make sure that the harness is neatly routed.
 
Back
Top