Electrical problem

Hi all been havin a prob with alternators on my 1997 300tdi disco ive had a couple of secondhand alternators an they jus break after a couple a months but the last 1 caught fire, put it out quick so no damage ta engine. Ive bin told this cud be because of short circuit, so i checked and redid the earths and check the cables goin to alternator an all is fine, the other thing is that when i push the break peddal down mi lights come on an lights on the dash come on ive solved this by takin RHS brake light out dunno why this worked but need ta get it sorted as drivin with 1 brake light is illegal an cant afford ta loose mi licence.

Cheers for any help Guys

Munka

I'd start by replacing brake bulbs, checking light fittings etc and all connections, then trace wiring back using a multi-meter or continuity tester (Bulb and two wires!!). Seems to me there must be a short or earth fault, or many faults for the symptoms you're getting. I'd also check the alternator fittings aren't bent/broken or something close to it is loose and connecting with it every so often.

Don't know about your alternator problem but you lights problem is probably a bad earth.
I'd look at three earth points first, the main body earth behind the battery onto the inner wing and the two earth points behind the front footwell plastic side panels. Clean all contact surfaces to bright metal apply vaseline and reassemble.
The earth points behind the plastic panels are bolts coming thro the sidewall with a number of black wires attached.
Just a thought regarding the alternator, have you considered a heavy cable (100A) from an alternator mounting bolt to the battery -ve terminal?
This takes out the worry about defective engine earth strap connections.