bjmusn

So my warning light came on, and was in the middle of a 500mi road trip but nothing seemed wrong. the next day the battery was dead, jumped it and drove fine. next day dead, and computer started going crazy (windows wouldn't work, no turn signals, stuck in 1st gear, SRS light..e.t.c..) Measured voltage from alternator (new battery), and it was 16.5. So, I changed the voltage regulator. everything is perfect and back to normal, if not better..

Now the crux.. the battery/alternator light is still on..

Now for the rub.. I was sent the wrong VR, nearly identical in every way but posts that guide the plug in were opposite, two on bottom and one on top, instead of two on top, one on bottom. It was a genuine new Bosch VR, but I got such a great deal I decided instead of paying shipping to send back i would try it.

So I cut the guide posts out and plug it in. Like I said everything running well but light still on. Voltage to battery is 14.3, voltage from the VR prong that the plug connects to is also 14.3. So I tried switching the plug around to the other prong, variable voltage about 11.8-12.

I know I should just order the correct VR and Mercedes wanted to do just that (without out considering other possible causes). Considering the voltage was high (16.5), my thought is that the VR is fine and the high voltage might have killed a relay/fuse? The alternator off the car passed voltage, diode and amp testing..

any thoughts?! Thanks!