Stef Posted July 12, 2012 Share Posted July 12, 2012 When I set off to Harewood this morning the left front indicator stopped working, the others work but flash quicker, as though the bulb has blown. I can't believe it's connected but just in case, last night I did the mod to the left rear lights to replace the silver reflector bits with the bigger ones from the bulk buy, all the lights worked fine last night. I've swapped the bulb and jiggled wires in case they were loose. Where do I start looking?.... I've never had a problem with the lights before. Cheers Steff Link to comment Share on other sites More sharing options...
OliverSedlacek Posted July 12, 2012 Share Posted July 12, 2012 Lights and indicators our coupled through ground wires, or lack thereof. Most such problems can be diagnosed with a multimeter. Do you have one? Link to comment Share on other sites More sharing options...
Stef Posted July 12, 2012 Author Share Posted July 12, 2012 I don't have one, no. Sounds like ill have to get one..... And learn how to use it! Link to comment Share on other sites More sharing options...
Stationary M25 Traveller Posted July 12, 2012 Share Posted July 12, 2012 Also check the flasher unit is pressed fully home - under the dash with the fuses. Do you mean cycle wing repeater or under headlight ? Often corroded earth. Link to comment Share on other sites More sharing options...
Stef Posted July 12, 2012 Author Share Posted July 12, 2012 The one under the headlight. I did have a scrape around the bulb holder with a screw driver and all seemed ok. Looks like ill have to get a book on electrics and start learning something! Link to comment Share on other sites More sharing options...
tangomikeromeo Posted July 13, 2012 Share Posted July 13, 2012 I had the same a while back (helpfully developed on the way to the MOT station) The cause was the solder holding wire to pin had failed and moved enough to break the connection at the multi connector. Follow the wire back from the lamp to the multi connector (black box cable tied to a cross brace for me) split this in two and check the connectivity with your new multi meter would prove the connection to discount this. Or in my case when one of the wires falls out that's the culprit. There was almost no slack in the cabling so I think my prior 'fettling' of the cycle repeater had dislodged it. Not sure this would make the others flash faster though - it didn't for me. Link to comment Share on other sites More sharing options...
Stef Posted July 13, 2012 Author Share Posted July 13, 2012 ok I don't get it. I bought a multi meter and bought the Haynes manual on electrical stuff. I put the multi meter on the indicator holder, both positive and negative, and it showed 10 volts or more when flashing. I tried the one that does work and it read pretty much the same. Surely that means it should work? What am I missing? I checked the earth bit sticks out enough so it is definitely touching the bulb and I tried several different bulbs,trying them in the other indicator to check they work. I also checked that the flasher unit, or at least what I thought was the flashes unit, is firmly pressed in. Any suggestions? Thanks Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted July 13, 2012 Member Share Posted July 13, 2012 Where exactly were the two probes when you saw that 10V across the bulb holder? Jonathan Link to comment Share on other sites More sharing options...
The Pikey Posted July 13, 2012 Share Posted July 13, 2012 What you need to do is the same test with the bulb connected. I am sure you have a bad connection or broken wire and this is dropping the voltage under the load of the bulb Check the green wire on the 6 way block as it comes out the headlamp stay (Check the car loom connector and the headlamp connector) If it looks ok remove the green/white or green/red pin (depending on which side you are working on) and run a wire from it to the centre connector on the bulb and see if it works. If it don't then run a wire from a decent ground or battery neg to the outside of the bulb and see if it works. If neither of the above works then the problem is further down the loom ☹️ Jason Link to comment Share on other sites More sharing options...
Roger Ford Posted July 13, 2012 Share Posted July 13, 2012 I bought a multi meter and bought the Haynes manual on electrical stuff. I put the multi meter on the indicator holder, both positive and negative, and it showed 10 volts or more when flashing. With or without the bulb in place? I'm guessing without. A meter has a very high internal resistance, so you would tend to see 12v-ish if you've got an earth at all, even if it's not a very good one. Look at this way. An indicator bulb is 21w - let's call it 24 watts for simplicity. That means it takes 2 amps at 12 volts. From V=IR, the resistance of the bulb is 6 ohms. That's not much. Now let's assume you have a poor earth with 12 ohms resistance. The voltage will be split between the bulb and the poor earth - 8 volts will be needed to overcome the earth resistance, and only 4 volts will be left to light the bulb. Yet when you stick your multimeter on, which has a resistance of hundreds of ohms, practically all the voltage goes to overcome the meter resistance, and almost none on the earth. So stick your meter on the resistance setting, and check the resistance between the earth side of the bulb holder and the battery earth. If it's any appreciate proportion of the 6 ohms resistance of the bulb, there's your problem. Alternatively, put the bulb back in, and measure the voltage across the bulb while it's flashing (or not, as the case may be). The voltage should be near 12v, if it's a lot less, then there's high resistance somewhere else in the circuit - probably the earth again. Link to comment Share on other sites More sharing options...
Stef Posted July 13, 2012 Author Share Posted July 13, 2012 Ok, I checked without the bulb in..... Obviously wrong. How do I test the voltage with the bulb in as the positive is covered by the bulb. As you can tell I have absolutely no idea about electrics! Link to comment Share on other sites More sharing options...
Roger Ford Posted July 13, 2012 Share Posted July 13, 2012 You could always assume the positive side is good, and put your meter from the battery positive to the bulb earth. If you have got a poor earth, you'll see it flicking between 12v when the indicator is off and when it's on. Link to comment Share on other sites More sharing options...
Paul McKenzie Posted July 14, 2012 Share Posted July 14, 2012 Just make sure when you split the mutiplug that the male pins are all protruding equally - I had this problem when one of the pins was not fully home in the connector. Paul Link to comment Share on other sites More sharing options...
Smiffy69 Posted July 16, 2012 Share Posted July 16, 2012 I had a similar problem on my Superllight. I noticed my indicators on the nearside were flashing faster than normal so after a quick inspection discovered that the nearside front (under the headlamp) was not working. I changed the bulb and still not working. In the end I tracked it down to the +ve wire breaking where it connects to the pad that makes contact with the bulb. Problem was that I had not put enough slack in the wire when building so with the vibrations caused by daily use it had fractured. Problem solved by soldering a short piece of wire on and reassembling. It's worked fine eversince Link to comment Share on other sites More sharing options...
myothercarsa2cv Posted July 16, 2012 Share Posted July 16, 2012 This happened to me on the way to the MOT (sod's law ). Swapped the bulbs over to check it wasn't the bulb, and lo and behold, the bulb was fine but jiggling it about did the trick! 😬 Most of the time my indicators stop working though, it's the earth under the wingstay. I'm just too lazy to extend it to the engine bay though Link to comment Share on other sites More sharing options...
Mark w Posted July 16, 2012 Share Posted July 16, 2012 Quoting Stef: the left front indicator stopped working, Cheers Steff no it hasn't yes it has no it hasn't yes it has no it hasn't yes it has no it hasn't yes it has no it hasn't yes it has no it hasn't yes it has Sorry , just couldn't resist it 😬 Link to comment Share on other sites More sharing options...
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