Date registered: Jul 2008
Vehicle: 1986/1990 W126
Location: Berkshire & Devon, UK
Mentioned: 28 Post(s)
Quoted: 1206 Post(s)
Good call, could well be a faulty alternator, especially if its a cheaper one. But even if not, don't rule it out.
I keep a little cheap charge Led indicator that tells me how many volts, just in case. Plugs into the cigarette lighter. You could try that as an easy option and you can see how it behave while running.
Daily transport 9spd Giant DH Comp downhill bike