Obc yellow wire

Post Mon Nov 09, 2015 11:06 pm

Hi all
On the back of my obc attached to the green plug wiring loom is a yellow wire with a white connector on it,is this supposed to be attached? I can't see anywhere for it to go? My obc is not holding its memory and I,m wondering if this could be the cause.
many thanks as always!!

Post Mon Nov 09, 2015 11:46 pm

jcm325 wrote:Hi all
On the back of my obc attached to the green plug wiring loom is a yellow wire with a white connector

Not used.

Post Tue Nov 10, 2015 11:24 am

thanks for the replies seems fuse 21 is ok but no12v live supply coming out? should this be 12v live at all times? I also have no interior lights/radio memory/obc memory...I presume if it should supply 12v live then the problem is on the pcb inside the fuse box?can I just run another 12v supply with the appropriate fuse etc and make this circuit live?
many thanks for any input....

Post Tue Nov 10, 2015 1:56 pm

Have you actually replaced fuse 21, preferably by swapping it with a known good other 7.5A fuse in the fusebox?
Find the fault, don't bodge!

Post Tue Nov 10, 2015 6:37 pm

Fuse 21 replaced original checked and fine still no 12v supply on wiring......voltage showing at inboard pin in fuse box with fuse removed =12v which is correct I think? Wiring checked for continuity from fuse pins all good......however the red and green wire which should be 12v is not showing any volts but is showing as going to earth? Any ideas why this is happening? Obviously I think this is stopping the wire from being live as it should be......
Hope this makes sense? My electrical knowledge is quite basic so go easy on me!!!!!
Items currently not working interior lights/boot light/radio memory/obc lit but no info showing I think all this is fed by fuse 21 also rev counter not working but don't know if that's related or not? Si batteries lithium non rechargeable recently replaced.....
Hope this makes sense as ever any help is greatly appreciated.....
And no I don't want to bodge it sorry if I gave that impression

Post Tue Nov 10, 2015 8:20 pm

Had a similar problem, boot, interior light, clock, radio, taco and other bits all stopped working maybe worth checking this out.

I found the fault to be the red and green wires that should be spliced together in the loom running along the seal about halfway up the passengers seat are completely corroded and broken, there are also other splices with signs of corrosion that will need attention. All repaired and working

Post Tue Nov 10, 2015 8:54 pm

A single thin red/green wire runs down the duct under the fusebox from the outer terminal of fuse 21 for a distance of just under one metre to the splice mentioned above. There is one wire going into the splice, and seven coming out - one to each of the services supplied by this fuse, so if everything fed by it is dead, and power is definitely present at the fuse, then either the wire has broken off at the fuse, or there's a problem at the splice, such as e30-wheels has said.
If the splice has corroded, then you should also be wondering where the moisture has come from to enable this corrosion. I've never seen this splice anything other than bright and shiny.

Post Wed Nov 11, 2015 1:48 pm

Brian is correct regarding moisture, the corrosion to my wiring was because the car was standing for 7 years and the metal around the big rubber grommet under the fuse box had rusted through allowing water into the passenger foot well

Post Wed Nov 11, 2015 4:33 pm

Thanks for the help guys I think I have found the splice just to be sure are all the wires coming out red and green?also I have 8wires coming out not 7? This splice is definitely corroded as I have removed the sheath......
Hopefully this is it I will advise on progress as soon as I get a chance!!!!!!
Thanks again

Post Wed Nov 11, 2015 6:19 pm

Brianmoooore wrote: There is one wire going into the splice, and seven coming out

7 + 1 = 8

Post Wed Nov 11, 2015 8:20 pm

I am aware 7+1=8 however I have 8+1=9 was just trying to make sure I am looking at the correct splice...hence the colour question.

Post Tue Nov 17, 2015 9:25 am

Just a quick update the splice mentioned above seems to be the culprit!! What a bad idea basically just crimping a bunch of permanent live wires together with some heat shrink over the top....anyway all services supplied by fuse 21 restored,I connected the wires one by one to the live just to make sure which supply was which and that it didn't blow the fuse......there were however 2 extra live feeds which don't seem to do anything when connected? Like I said everything mentioned on the fuse diagram is working so maybe they are pre installed for options I don't have?
Anyway thanks for the help the info on the splice was awesome and sorted everything......just a few more problems to go and I might get finished!!!!!!!!

Post Tue Nov 17, 2015 1:41 pm

Good result, did you find the cause of the corrosion?

Post Tue Nov 17, 2015 7:01 pm

yes the cause is a split in the doorseal just above that splice!! car is parked nose down and it just runs in over the cill....must have been happening for ages as the floor was rusty there too...had to do a repair!!

Post Mon Nov 30, 2015 11:38 am

Ok car is being a pain again!!!!! As above everything was working perfectly however I now have no rev counter/econometer and my service indicator light is flashing like crazy? Si batteries lithium non rechargeable recently replaced and si board and cluster inspected all solder seems to be in good condition? I have just finished wiring my stereo/electric aerial in and now this happens....I have disconnected the radio and aerial just in case I f***ed anything up but it is still happening,all fuses have been checked.......
I.m presuming the si board needs replacing? Any help as ever would be appreciated.....

Post Mon Nov 30, 2015 1:40 pm

Are you 100% certain you used the correct type of battery?
Are you certain fuse 21 is OK? (Interior lights and clock won't work if it is blown.)
Check the voltage across each of your SI board batteries.

Post Tue Dec 01, 2015 8:24 pm

ok ,yes correct batteries used,voltage checked all good,fuse 21 good all supplies functioning.
after checking everything and pulling my hair out i decided on a shot in the dark,i disconnected the battery for 10 mins then reconnected and then carried out a reset of the insp light/oil service using the reset tool and guess what? all good rev counter works SI lights work correctly???? obviously i.m pleased but not sure if i have solved this issue totally?
it will probably come back to bite me on the ass!!! but i am fairly certain my wiring is good and any fault lies with the SI board/batteries etc.

thanks to everyone who has contributed to this thread without your help i.d probably still be scratching my head