I’m going to blame this question on the SNG parts catalog. While paging through looking for a rear view mirror, I happened upon the page illustrating the wiring harness for the car and that it was possible to replace only sections. Until that moment, I thought it was an all or none part.
Right now, I have the interior out of my car while working on some other mechanical systems, but I’m closing in on installing a new interior kit from BAS in the UK. I’m trying to make sure that anything that might require me to tear out the interior again is dealt with needed or not. While cleaning up the interior, I’ve constantly noticed how tatty the two side wiring harnesses are that go along the side panels. I now see that these two sections of the wiring harness are available separately and aren’t prohibitively expensive.
The big question is, how painful would it be to replace both of them? I’m sure someone here has done this, the question is did they do it when the car was assembled or disassembled. Thanks in advance for insight.
I inspected mine before I covered the sills and though they looked a bit ratty the inner insulation was sound and they all tested fine. In the end I just left them as I found them.
One change I did make was to run a cable for a rear camera from the boot to the dash. I haven’t put one in yet but anticipate I may since I plan to drive with the hardtop on.
BTW - It appeared to me that there was some redundancy built into the left and right harness.
If your talking from dash to tail lights, It gets a bit bloody…
It all runs through the passanger side…fishing over the rear wheel arch is the bitch
GTJOEY1314
I have harnesses showing on both sides. The SNG chart seems to indicate that both sides feed the brake lights, turn signals, and backup lights. The right side feeds the fuel pump and hand brake switch, the left side feeds the interior light.
I had a challenge pulling a new set of antenna wires (signal, positive power, and up/down switch). But I got them pulled. Maybe its naive but if I had to pull both sides, I would use the existing harness with nylon line taped and secured to one end to fish the new harness through on each side. Although Geo make a good point to leave them alone.
My take is that it will never be easier to do than right now. You can use the old harness to pull through a rope to then pull through the new harness. It is not an expensive harness. When you have problems with that old harness 2 months after you glue in the upholstery you wil uttering choice swear words. Copper stranded wire does degrade internally just due to age and corrosion. For all those reasons, I would replace it now.
Harvey, you and I definitely are thinking alike on this. If I have a wiring issue after this beautiful interior is fully installed, I might sell the car to avoid tearing it all out…
Agree 100 percent…I would do it but thats your call.
Then you know its done. On the 67 I did exactly that, Black tape the NEW harness to the old one then pull it back toward the boot.
Good luck , PLEASE DONT USE the Welsh supplier for that harness, SNG okay or go all the way with british wire company.
GTJOEY1314
I have done this exact job a few times now. It is nothing to be worried about. The looms are small and available separately form Autosparks. Lead times are bad at the moment (3 months?).
You could actually make a pair of harness yourself from the 2 you remove, or buy them from auto sparks for about $100 + delivery. They are simple harnesses.
Both LHD and RHS detatch with bullet connectors in front of the doors at the side of the dash. They are readily accessible and they run into the footwell and along the sills behind the sill tangs into the B-posts on either side.
They then pass through 2 rubber grommets over the rear wheel tub and into the boot.
On the LHS is a spur for the interior rear light. The connection is actually over the rear tub.
Then the rest of the wires go the the rear lights.
On the RHS is a spur for the hand brake switch. Then the loom passes through the 2 grommets behind the b- post over the wheel arch to the fuel pump (black and white wires) and the rear light unit on that side. One of them has a spur to the reversing light, the number plate lights a join together.
With the trim removed it takes about 10 minutes to pull each side and 15 minutes each side to poke the new looms through. Honestly.
Use a coathanger wire and tape.
It really is not difficult, I did one three weeks ago .
Infact I we fitted a whole loom on a crash damaged car in a morning including the dash and engine. The loom on that car was 1 year old, so in good condition.
I was cheating though! When the car was disassembled I unclipped the engine bay wires and carefully pulled them though the 3 holes (2 holes on the lhs, one for the wipers on the rhs). I unplugged the side looms from the main dash harness.Then I unbolted the the three dash panels (top removed) and extracted the whole center dash with the loom still attached and put it in a nice big box. I unplugged the other wised on the speedo/rev counter section.
It made refitting super quick as I just bolted the center section in and pulled the wires back through as per the pics I had taken on the mobile phone in my pocket.
Thank you for such a great explanation and encouragement. I was just out in the the garage surveying the task. The left hand side does indeed terminate with some bullet connectors right next to the turn signal relay and seems like an easy task aside from any complications getting to the spur for the interior light in the boot.
The right side seems a bit more fiddly, given that I have an aftermarket AC unit hanging down in my way to where ever that harness terminates. I have traced it up the foot well to under the right side of the dash, but lose it there. Does it go all the way to the fuse block?
Ref LHS It goes from the dash, to the area in front on the top of the door at the top of the footwell, then splits with the bullets. The LHS side harness then travels behind a long removable cover at the top of the footwell, travelling forward then does a 90 degree turn to the floor, then a 90 degree turn along the sill in the tangs heading to the rear of the car, below the door and into the b post.
Not sure if you would have to remove the ac vents to pull it out. I suspect not.
When you have removed it you will see how easy it would be to reproduce on a bench. It is literally a few wires of a certain length and color.
I goes no where near the fuse block, you detach it from that harness where the bullets are in front of the lhs door.
