It has been suggested on here that people should check the wiring voltage to the headlights if the lights seem below par. Could somebody tell me how to do this? Would any cheap multimeter do, like the ones you see under 10 quid in markets, boot fairs and cheap tool shops? Analogue or digital best to buy?
Could somebody tell me how to check it? The connector type is for H4 type bulbs.
maplin have got multimeters at the moment for £3 and that'll do fine. pull the plug off the headlight, turn on the headlight switch, turn the multimeter to the 20v dc range and measure across two of the three contacts on the headlight plug. if you get no reading, swap contacts. I think it's the centre contact (at right angles to the other two) and one of the other two depending on whether it's dipped or main beam.
Get a normal multimeter, set it to a range a little above the car voltage, so in this case it would be 20 volt DC, you need to check the voltage under load and the quality of the earth connection. Turn on the headlights and with the back of the bulb connector exposed, connect the negative probe of the multimeter to a good earth connection on the body or the battery minus, check how many volts you have available at the battery by putting the positive probe to the plus side of the battery, you should get a reading of a little over 12 volts, mentally note this for later. With the negative probe still on earth or battery minus put the positive probe to the dip beam connector on the back of the bulb, this is the top connector at right angles to the other two, you should get a reading close to the battery voltage, but anything above 10 volts is ok. Now check the earth lead, connect the positive probe to the earth connector , this is the left hand connector as you look at the back, the voltage should ideally be almost zero, but below a volt or so is ok.
Likely problems are most likely to be a bad earth connection.
mrcheerful
Once you have found the earth point (almost certainly the centre) then measure voltage from that back to the negative terminal of the battery. If there is more than a few millivolt then you have a bad earth.
Check out this excellent guide on the ClioSport Forum:
/Mad
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