Loom and part i have labelled but ink faded

[Lobo]

Just one other thought Mike, and am wondering whether all this damage can be a result of a regulator failure.... ie the alternator is producing full power all of the time. This though would quickly trash the battery... did that happen? Trigger, did you replace any other electrical components @ the time you replaced the fuse box / service the electrics (eg cleaning up grounding points)?

Many 550 owners on here (I'm not), is this a common fault gents?

[LesterPiglet]

Mine is all ok. I changed the rectifier a long time ago but I can't remember why now. It's from a 750.

[MikeM]

lobo cant answer that question bike sat since 1983 ?

who knows whats happened since ?


hopefully geting a new fuse box from member going to attempt to replace al lthe green wire through out the loom and clean up al lcontacts and sort out grounding points

if that dont work the bike will appear in parts on ebay

[Trigger]

Lobo, i am in the same boat as Mike. I don't know any history of my bike, apart from the loom was butched to hell. I  found No burnt wire's from the regulator or rectifier, only from the fuse box to the connecting block and from the block to the multi join of earth wires. Which is the connection that is soldered. 

[MikeM]

bedtime video

any evidence of rectifier damage ? I am not so sure

thinking bad earth........

getting interesting though 

http://www.youtube.com/watch?v=d1VFYYaxDys&feature=youtu.be

[LesterPiglet]

Just replace the green. You won't be able to tell until it runs. I doubt a bad rectifier would cause that. It's been a short or reversed polarity.

[Lobo]

The RECTIFIER changes the alternator's output from AC to DC.

The REGULATOR then regulates the voltage (which otherwise would rise unchecked with alternator speed) to a maximum of approx 14.5V. If OEM its a fairly mechanical device with breaker points within which should close at around 14.5V; this is adjustable vis a small screw. The points also need to be gapped / cleaned if the device not performing to spec.

Mike; I'm NOT saying this is the problem, but I am suggesting, if no other obvious causes to check out the REGULATOR.

As a simple 'starter for 10' if you open it up & find the points stuck / seized in the 'up' position you may have your answer. (although if 'ok' on this test you'll still need to verify they close @ 14.5'ish volts later on)

Simon

[MikeM]

understood, i will check out regulator and rectifier and re wire, make sure all contacts are clean good clean earth contacts if that dont work i will chop it up 

[Bryanj]

The most common reason for the loom earth lead to melt, especially if all others are OK, is a bad connection on the main earth lead at the engine end meaning that that small green wire takes starter current

[Lobo]

...that makes a lotta sense, especially given the other leads ok.

Anyways, not an answer, but a read ..

http://www.dansmc.com/electricaltesting.htm

[MikeM]

The main earth lead wire was caked in grease, mud and grot, very flaky

also the melted wire goes back to the earth point at coils, so it ties up 

[Lobo]

.... that's Bryan for you; a man of few words, but when he says them they count!

[K2-K6]

+1 with Bryan on that. it seems fairly unimportant until it goes wrong!

older cars are like this as well and it usually fries even the thottle cable as it tries to scavenge an earth conection any way that offers a path back to the battery.

[Trigger]

Yep, Bryan must be spot on  ;)because i have had every electric part tested and can not find any problems.

[MikeM]

got a new rectifier and getting consistent results..... looks like old rectifier was indeed faulty or damaged

now also thinking wire section on back of regulator needs looked at and may just change this

anyone have a spare or tell me what other bikes I can look at to get this section