Voltage up and down

[kelvinhill56]

Hi
Have a 2003 diesel estate with the lights flickering a little.
All electics seem to be working ok so lived with this for some time now.
Voltage varying by about 0.3V, doesnt sound a lot but think it should be solid.
No warning lights on and belt tight.
Suspect the regulator.
Can anybody tell me is this part of the alternator...can I buy/change it?
Any advice much appreciated

[Astraeus]

Hi
Have a 2003 diesel estate with the lights flickering a little.
All electics seem to be working ok so lived with this for some time now.
Voltage varying by about 0.3V, doesnt sound a lot but think it should be solid.
No warning lights on and belt tight.
Suspect the regulator.
Can anybody tell me is this part of the alternator...can I buy/change it?
Any advice much appreciated

Hi mate
Regulator part of the alternator. Measure the voltage across the battery terminals when engine running. Should be more than 12. Between 13 and 14 volts. When switch off voltage should settle to say 12.6.
Check carefully that the battery is earthed properly and terminals are clean.
If all ok wouldn't worry too much.
Chris

[Astraeus]

Hi
Have a 2003 diesel estate with the lights flickering a little.
All electics seem to be working ok so lived with this for some time now.
Voltage varying by about 0.3V, doesnt sound a lot but think it should be solid.
No warning lights on and belt tight.
Suspect the regulator.
Can anybody tell me is this part of the alternator...can I buy/change it?
Any advice much appreciated

Hi mate

Get along to the meet and get your car checked out by the T4 machine. Checks everything and gives fault codes. See info in Scottish Events thread

Chris

[mamasboy]

Hi
Have a 2003 diesel estate with the lights flickering a little.
All electics seem to be working ok so lived with this for some time now.
Voltage varying by about 0.3V, doesnt sound a lot but think it should be solid.
No warning lights on and belt tight.
Suspect the regulator.
Can anybody tell me is this part of the alternator...can I buy/change it?
Any advice much appreciated

What measuring equipment are you using? If a cheap multimeter I'd pay little or no notice. If an oscilloscope, if you see some high/long transient spikes then your alternator could be on it's way out.

At idle a car (even the most refined engine) will fluctuate it's revs which will load the alternator in a non linear manner. When you measure the voltage across the battery terminals, the voltage will vary slightly due to this loading effect. A good indication is if you are constantly blowing bulbs. This happened to me an Seancar fitted me a new alternator and has been perfect since.

[kelvinhill56]

Thanks for that
All been done and looks ok so maybe a nother alternator in the future as the lights not right in the dark.
I may well get along to the meet to see whats going on.

[kelvinhill56]

Thanks for info
The multimeter is a decent one used for work.
Measured my work vehicle which is solid so something is up.
Brake bulb went yesterday but first bulb in over a year.
Live with it for now and think about another alternator in the summer
Cheers for help