I started my car today a my02 sti and the battery light came back on before i moved the car, but as soon as i started driving the light went out, then i stopped at a set of traffic lights and it came on again, but this time the brake warning light also came on and the water temp gauge was showing lower temp than normal.

I stopped the car and took a look under the bonnet, the charging cable on the top of the alternator was broken away from the ring terminal, it looked melted, so i cut back the burned wire and fitted it to a new ring terminal and bolted it back on to the alternator, i then started the engine and everything on the dash was normal all warning lights were out, i went out to close the bonnet and noticed smoke coming from the cable i had just re-fitted, and the terminal on the alternator where it attaches was burning hot to the touch, so i turned off the engine before the cable melted.

Any ideas what the cause of this could be ?

Thanks in advance

 

Sounds like a dead short in the charging circuit. I'd take it to an electrical repair place asap.

Alcazar

 

sounds like the alternator is over charging done this on my99 i repaired the cable then took a reading with volt meter 18volts at the battery (engine running) not good. the battery was well over charged . if i remember sit down when subaru give you a price . scott

 

Cheers guys, but i got it all sorted out today, i replaced the complete charging cable from the top of the alternator to the fuse box, there was corosion all the way along the wire that i couldnt see causing a high resistance, i made up a new cable and problem solved, engine off 12.7v engine on 13.9v.

 

Very odd. I can see it would cause resistance, but how did it ghet corroded so far down the cable, so fast?

No-one spilt any battery acid down near it have they?

Alcazar

 

Not sure m8 when i say all along the cable it was about the first 12" from the alternator, the fusebox side was fine.