4L0 wiring advice needed

[shaunthe2nd]

I'm well on with a 350LC 4L0 build.
Just about everything has been done and getting ready to put in engine/carbs/exhausts but I have an electrical problem on the rolling chassis.

The bike came with a new loom. It looks original but could be a copy as I had to swap over 2 connectors which weren't right.

I have fitted and wired up all the electrical devices, put in a battery and it seems that most things work, BUT the rear left indicator remains on. 

Whilst investigating this problem, it appear that even if i remove all 4 fuses from the box, pretty much everything still works!
This I suspect is my real problem, the indicator lighting up is probably a symptom.

I have swapped a lot of parts over with others from a working bike including the indicators, flasher unit, clocks, switch gear, regulator, front and rear brake switches, rear light assy, etc but the problem remains, so I suspect its down to the wiring loom?

I have cleaned and re-tapped the earth point next to the coil, but again, most items work with or without this earthwire connected.

Anyone had something similar or any suggestions where to look?

All help appreciated, thanks, Shaun.

[4l04ever]

I have a good quality colour scan of the wiring diagram I can send you. pm me your email address.


Does the power stay on all the time?

[earthman]

I'm guessing that something could be a miss with the whole fusebox set up for a start? Removing all fuses and still getting power sounds like either it's not been wired correctly or there's a short somewhere, maybe the main + feed from the battery is finding another path? How odd, interested to know the actual cause.

[4l04ever]

I have spoken with Shaun on the phone. Seems to be a wiring/loom issue as appears to be a pattern loom. I remember some pattern ones which had a few different connectors, so could be one of those.

On Shaun's bike, the fault appears to be that there is a connection made between the red wire coming from the battery + to the top of the main fuse, and to the red wire coming out of the bottom of the main fuse in the loom, so Shaun will strip the loom back from the battery + to the fuse box to find the join/short.

[muttsnuts]

ignition switch faulty or wrong one fitted?

[4l04ever]

Power fault still evident with ignition switch unplugged and reg/rec unplugged. Main fuse out, and power is still on both main fuse terminals.

[4l04ever]

The issue is only in the red wires. Brown wire does not go live.

[shaunthe2nd]

Thanks Rob and Dave for some help. Hopefully I have now solved it with your input.
It seems to be a problem with mis-wiring within the loom. I wanted to be sure it wasn't any of he electrical components before I dissected the loop.

Rob (4l04ever) talked me through some possibilities, and by elimination I found the problem and does appear to be a fault within the loom.
It was wired to put 12v on both sides of the main fuse rendering the fuse useless.

I have now temporary rectified with twisted connections and over the next few days will re-solder and re-wrap the loom. I like to take my time for that.

From this i can summarize it must have been a copy loom, i purchased this on ebay some 3+ years ago and never used, and also had to change over 2 connector blocks which weren't correct. Apart from that its been great.

The decision to re-use an old proven loom or use a new copy one is marginal! Lol.

Thanks for the help guys.
Shaun

[shandyboy]

Shaun I have a genuine NOS loom in the packet let me know if you need photos of it to compare with yours Buddy ??

Alan

[shaunthe2nd]

Feb 26, 2019 0:07:36 GMT 1 shandyboy said:

Shaun I have a genuine NOS loom in the packet let me know if you need photos of it to compare with yours Buddy ??

Alan

Alan thanks for that offer but you would have to unwrap the loom to show me what I needed to see as it ended up the wiring and not the connectors. The main fuse was wired in parallel rendering it useless and one if the rear indicators was permently live too!
I figured it out in the end but had to unwrap half of it to sort it. It's all sorted now but thanks for you kind offer cheers.

[shandyboy]

No Worries Shaun