Headlights

[Sprinter]

I've got a strange issue with my headlights, when riding with low beam only the right lights low beam is on. The pilot light is on the left light, as soon as I go above about 7,000RPM the left light will kick in and stay on till I put it away for the night. Or it will kick in if I put full beam on, it will go off when I go back to dipped beam. I've checked voltage and they are about 14.5V without lights and about 13V with lights, any ideas on what it could be? The connection to the bulb as fine.
James

[wullvfr]

when you say low beam at the start of your post are you talking about main beam(dipped beam)????

how does the wires look in and around the headlights?it could be poor continuity etc.have you checked connections to see if there is definately voltage getting to the bulb?


william

[Sprinter]

Yeah sorry I mean dipped beam, the wires look ok there's no slices or cuts in any of them. Just seems a little strange that once I've gone above 7,000RPM it's fine. What's the best way to go about testing the voltage on the connector for the bulb?
James

[wullvfr]

i personally use a multimeter set to dc volts 20 range........

remove the connector from the bulb,when you are ready to test for voltage turn on the ignition and put the lights on to dipped beam........there is three contacts inside the connector,put one probe on one and the other probe on another and you should get a reading of 12volts,if you dont keep trying the probes on different contacts until you do....and if you dont then you know it is not geting voltage.

william

[Sprinter]

Ah ok cheers, I just didn't know the voltage I was looking for as I couldn't find it in the Haynes manual. Ill let you know how I get on.
James

[Sprinter]

Right, checked both headlights. The offending left one is getting 10.5V, the right 11.9V. That's from cold so I haven't checked the left one once it has come on, however the voltage is the same when I put it on high beam which is when it works. Any ideas why it's not getting enough voltage?
James

[wullvfr]

more than likely a problem in the wiring,poor connection...possibly the connector that the bulb goes into may be poor!!!!

maybe when you are riding the vibration on the road helps it come on!!!!

it's strange how the readings are the same for full beam but this time the lights work

swap the bulbs round and see what happens then,if it happens to same bulb but on the other side then i reckon its tha bulb thats faulty....but if the same side does it then you know for sure its not the bulb.


william

[Sprinter]

Ill try that tomorrow, I feel stupid that I didn't think of something so simple!
Cheers mate Ill let you know how I get on.
James

[Sprinter]

Just incase anyone wondered, it turned out to be a strange defect with the bulb.
Cheers for all the help.
James

[wullvfr]

good find

im guessing it done the exact same on the other side?




william