Voltage variation
I have a fairly expensive and hopefully accurate digital voltmeter connected to my 2005 Honda Accord 2.4 petrol via the 12V socket. It has always shown my alternator to put out between 14 and 14.3 volts, but recently this has dipped to 12.5 volts and varies between this value and the previous high of 14.3. The idiot light on the dash hasn’t lit thus far. My diagnosis is that the voltage regulator is on the way out. What do you think?
The alternator looks fairly accessible on the front of the engine and I was thinking of replacing the regulator/diode pack. Would you advise fitting a reconditioned unit? Are there any hidden dangers in removing/replacing the alternator on these vehicles? Gary Mills The symptoms you describe do indeed sound as though the alternator is beginning to fail. Being able to see this problem through the fitting of a voltmeter highlights one of the reasons why a simple warning light does not replace an accurate gauge. I would check the continuity of the wiring to the alternator before confirming that this is the cause, if possible checking the voltage at the alternator terminal directly; this will eliminate a possible failure in the loom. While the problem may be due to the diode pack, it could equally be down to worn brushes which are failing to make a good contact continually. For this reason, unless you can also replace the brushes (which are incorporated into some diode packs) I would plump for the reconditioned unit. The book time for the replacement of the alternator is 0.9hrs and the job should be quite straightforward.