240 Background: I wasn't driving the car for about 6 weeks; when I went to start it, the battery was flat (ish). Jump started it no problem, but over the next few days it failed to start a few times so I bought a new battery. The old battery was 9 years old so it made sense for it to have failed, so I didn't mind replacing it anyway. There is now an odd issue with voltage. I have a volt gauge in the car which normally sits in the middle (between about 13 and 14 volts). Every few minutes, it will drop down to about 11.5 volts and the battery light on the dash will come on faintly. After a few seconds it will often go back to normal, or if it doesn't, I can get it to return to normal by pressing the clutch and revving to about 5000 rpm. I've checked voltage at the battery with the car running which was about 14.1 volts, but the fault didn't occur this time so technically it passed an alternator test. But something is obviously wrong. Could it be the alternator? Or maybe the new battery is a dud?
paul0075 Voltage regulator on your alternator. I had exactly the same issue on my 93 244. Replaced the regulator and erratic readings went away
paul0075 eBay. From Lithuania, 2 weeks, $18 delivered. Just replaced the one on my 89 245 on Saturday with it