Alternator/Battery Cable.....

[Railroad]

I've noticed on my Octavia TDi that the alternator cable on top of the battery, and right next to the 110A fusible link gets very hot when the headlamps, heated screen and fan blower are all on. The cable has also discoloured due to the heat and resistance, and I've measured a volt drop of 0.8V under load between the cable and the terminal where it crimps. I've seen this before on other VW/Audi models and Ford Galaxy vehicles, so I'd say it's relatively common.

I want to renew the cable, but rather than make one does anyone know if the individual cable is available to buy, or is it part of the complete loom?

Thanks in advance.....

[Tech1e]

Yep you can get the cable on its own.

[Railroad]

Yep you can get the cable on its own.

Does it run from the 110A fuse directly to the alternator or to the starter motor?......

[Tech1e]

Direct to the alternator. The starter motor wire goes direct to the battery terminal.

[Railroad]

Direct to the alternator. The starter motor wire goes direct to the battery terminal.

Great, thanks for that. I'll order one tomorrow.......

[AcW]

Check the fuse box, you may find that the fuse is damaged and the fuse box burnt, do it now as the alternator goes if you leave it.

Andy

[Railroad]

Check the fuse box, you may find that the fuse is damaged and the fuse box burnt, do it now as the alternator goes if you leave it.

Andy

Thanks for that, the fuse box is in perfectly good condition and the 110Amp fuse is as clean as a whistle. The problem was a bad connection between the cable and the fuse. It showed signs of being left loose because pitted burn marks were evident. This would've caused a resistance, and therefore a voltage drop could be measured between the alternator and battery.

I've replaced the cable now and the voltage difference between the alternator and battery positive is now around 155mv with all loads on. Charging voltage is now around 14.2V with no load, and 13.6V under full load. The alternator was loaded at 75A with headlamps, heated screen and heater blower on. It's difficult to see how I could get much better than that.....

[AcW]

Looks like you got it in time, mine melted the fuse mount then the altenator went, i think i was £300 in total to get it fixed. happy days

[cookie-859]

YOU SEE "AcW "WE AREN'T THE ONLY ONES!!! Geerrrrrrrrrr!!!

[stewmitch]

had the same problem with lead corrosion on lead from altenator burt out fuse box twice now i think there is a design fault on the lead as mine is a 120 amp altenator and the cable on default lead looks to thin for 120 amp cable..and connections seem to corrode ..just had a new lead made out of 170amp battery cable and carefully stripped the old cable down to retreve alternator/ air con block connectors then put them on new cable and heatshrinked the lot.....also rebuilt a new battery top fuse box and made sure all nuts were replaced . going to get alternator and regulator checked now to be sure no other problems ..but this seems to be a common problem on a lot of vw group cars (mine octavia tdi) so if your reading this check your alternator fuse (usually 110 or 150 amp, in box on top of battery)

alternitvily you can buy the new cable from dealer 1J0971349 (FQ) last letters may be diffrent !!

Edited 23 January, 2011 by stewmitch

[stewmitch]

I've noticed on my Octavia TDi that the alternator cable on top of the battery, and right next to the 110A fusible link gets very hot when the headlamps, heated screen and fan blower are all on. The cable has also discoloured due to the heat and resistance, and I've measured a volt drop of 0.8V under load between the cable and the terminal where it crimps. I've seen this before on other VW/Audi models and Ford Galaxy vehicles, so I'd say it's relatively common.

I want to renew the cable, but rather than make one does anyone know if the individual cable is available to buy, or is it part of the complete loom?

Thanks in advance.....

[stewmitch]

buy a new cable its safer cable number should be on label by fuse box end, beleve this cable has been superseded