RobMoore606 Posted November 27, 2011 Share Posted November 27, 2011 I could use some pointers in trying to identify or how to fault find an electrical fault.For a few weeks now when turning on my lights it often took a few goes at rocking the dash switch before they would actually come on.I figured there would be lose wire someplace and yesterday I turned the lights on and the green/res wire coming from the switch got hot and caused some smoke.I have working headlights dipped and main beam, brake lights, reversing lights and indicators working fine.Everything electrical is working apart from: Side lights, dash lights, number plate lights and rear lights are not working.I have cleaned all connections and still nothing.I have a multimeter but lost instructions lolhow do I test the rocker switch and the wiring? Link to comment Share on other sites More sharing options...
Velocita Rosso Posted November 27, 2011 Share Posted November 27, 2011 Put your meter onto continuity eg touch probes and it should buz beep etcPut one probe on one side of switch terminal and the the other probe on the other terminal/s and see if current is passing through when rocked either waySounds like a faulty switchTry that first etc Link to comment Share on other sites More sharing options...
drofgum Posted November 27, 2011 Share Posted November 27, 2011 Rob,Il Capo's instructions are OK except that if you do that with the battery connected the meter may not like it. It would be better to check any set of terminals with the meter set on volts first to assure yourself that you aren't going to feed 12V into the continuity function of the meter, or to disconnect the battery before doing as he has advised. Best of luck, Paul Link to comment Share on other sites More sharing options...
RobMoore606 Posted November 27, 2011 Author Share Posted November 27, 2011 Thank you both.Also noticing that even though I have headlights main and dipped I am unable to flash them off the stalk.I Swapped the blue wire and the red/green wires around on the switch and this lights up the headlights on both positions of the switch as I was expecting, this to me would indicate that the switch is ok.I then disconnected the battery and have checked the (my meter dont beep) the green/red wire from the switch to fuse has continuity (no need to test the blue as this supplies headlights) Link to comment Share on other sites More sharing options...
RobMoore606 Posted November 27, 2011 Author Share Posted November 27, 2011 battery connected, I have voltage at reg/green terminal and blue terminal. Its now looking like the fault is after the fuse. Link to comment Share on other sites More sharing options...
rotoflex Posted November 27, 2011 Share Posted November 27, 2011 I agree that the switch sounds like it has an intermittent fault.Rocking the switch to make it work would have me buying a new switch, or at least spraying the innards of the existing one with electrical contact cleaner to see if it were just dirty contacts. Link to comment Share on other sites More sharing options...
RobMoore606 Posted November 27, 2011 Author Share Posted November 27, 2011 rotoflex wrote:I agree that the switch sounds like it has an intermittent fault.Rocking the switch to make it work would have me buying a new switch, or at least spraying the innards of the existing one with electrical contact cleaner to see if it were just dirty contacts.The switches come apart? I was toying with opening but didnt want to break it so left it be. Link to comment Share on other sites More sharing options...
drofgum Posted November 27, 2011 Share Posted November 27, 2011 Rob,I'm not sure if your car has this, but some have the fuse clips set up so that the end of the fuse connects the two halves of the clip at one end of the fuse. A bad connection to either side of the clip will leave some things disconnected. If you are sure that the switch sends power through where it ought, you might want to check across the ends of the fuse. Best of luck, Paul Link to comment Share on other sites More sharing options...
Marcus Posted November 27, 2011 Share Posted November 27, 2011 Rob,The lights switch is fed directly from the battery via the starter solenoid. The supply is not fused. The R/G wire from the middle contact of the switch goes to the middle fuse and then on to the sidelights, dash lights,number plate lights, etc. In your case it would appear that this fuse or a connection to it has failed.The blue wire from the bottom switch connection goes to the mai beam/dip control stalk and then on to the headlights. NOTE the headlight supply is NOT fused!! WHY!!The main beam flash supply supply to the "flash" control is from the bottom fuse and not dependant on the lights switch.Hope this helps, Mark. Link to comment Share on other sites More sharing options...
junkuser Posted November 27, 2011 Share Posted November 27, 2011 "I turned the lights on and the green/res wire coming from the switch got hot and caused some smoke."This is the worrying bit. A short should be ruled out. Link to comment Share on other sites More sharing options...
AngryBaldMan Posted November 27, 2011 Share Posted November 27, 2011 I would have thought to cause heat n smoke the wire would have to short to earth. As the switch cannot switch to earth as it only has a live and two load wires I would have though the fault would be further down that wire towards the lights. Try running wires from the switch externally just to one headlamp. Link to comment Share on other sites More sharing options...
RobMoore606 Posted November 28, 2011 Author Share Posted November 28, 2011 Cheers fellas.I will check more wiring over the next few evening if rain permits.I did a continuity test up to the fuse box seems ok, out of curiosity i did continuity checks on the fuses and I found I have continutiy from top fuse to middle fuse :-/ I'm prety sure that no fuse should have continuity with another but please correct me if I am wrong. Link to comment Share on other sites More sharing options...
rotoflex Posted November 28, 2011 Share Posted November 28, 2011 3472 wrote:The switches come apart? I was toying with opening but didnt want to break it so left it be.I've seen the Clear Hooters switches apart. Like you, I wouldn't attempt to disassemble it because of fear of the plastic breaking.I usually just take them out, spray contact cleaner in all the cracks, & work the switch through all the switch positions as it drips contact cleaner. Link to comment Share on other sites More sharing options...
nang Posted November 28, 2011 Share Posted November 28, 2011 Looks like you'll need to replace the smoke that you've lost :) Link to comment Share on other sites More sharing options...
junkuser Posted November 28, 2011 Share Posted November 28, 2011 A short to frame at the back of the fuse box would account for the original symptoms, so worth ruling out. Worth taking it off and having a look for any evidence of burning/tracking.Don't know the circuits in your car but your fuse findings could be due to short or via a normal circuit. Link to comment Share on other sites More sharing options...
mark spit Posted November 28, 2011 Share Posted November 28, 2011 3472 wrote:Cheers fellas.I will check more wiring over the next few evening if rain permits.I did a continuity test up to the fuse box seems ok, out of curiosity i did continuity checks on the fuses and I found I have continutiy from top fuse to middle fuse :-/ I'm prety sure that no fuse should have continuity with another but please correct me if I am wrong.You will find continuity from fuse to fuse as they both end up connected together at somepoint on the route from the battery.The fuses protect whatever is before them from short failure or excessive current draw of a component after them.The switch is fairly easy to dismantle and clean out. Your hot wiring could just be down to the core being very old, happened on my Spit headlight wiring under the dash, smelt it before it let the smoke out though. Now have new fused & relay fed headlight wiring.Mark Link to comment Share on other sites More sharing options...
RobMoore606 Posted November 28, 2011 Author Share Posted November 28, 2011 I have heard about fused and relay fed headlights. How does one go about doing this mod? Link to comment Share on other sites More sharing options...
mark spit Posted November 28, 2011 Share Posted November 28, 2011 Easy one really.There's been plenty of write ups before...Anyway, you'll need some suitable cable, preferably the same colour scheme as the existing wiring to the headlights, blue/red and blue/white I think.Either a couple of inline fuse holders ar a new small fuse box to take blade fuses. I got a 4 way one and have since used the other two positions as well.If you can stretch the cost out, two of the headlamp connector loom sections.Two relays.Mount your fuse box as close to the battery as possible and take a permanent 12V to it. I used eyelet terminals and connected them onto the solenoid.From the fuse box, run cables down to near the front where you can mount the relays.Mine are on the engine valance next to the radiator support.Run new cable out to the headlamp loom connectors.Strip back the original headlamp loom from the connector and fit and trim the priginal wiring so it can trigger the relays.To get your cable / relay / fuse ratingsBased on a pair 65/55 Watt headlamp bulbs. You will need cable and components that are rated above 12Amps to feed both main filaments, so fuse at 15A, cables and relays min 20A. Should you be tempted by 100W bulbs, you'd be drawing 16A so need ratings of at least 20A for the fuse and above for the cable.IIRC, I got 30A relays, 15A fuses and 20 or 25A cable for safety.Everything you need is available from Vehicle wiring products, though other suppliers are available. I paid less than £30 for everything. Kits are available as well with everything already in them. I'm sure if you search around the forum there's a wiring diagram and which pins on the relays you need to connect the various cables too as this is one of those FAQs.It's well worth doing, especially if you also change to halogen bulbs at the same time.My old wiring was giving me a 3V drop by the time it got to the headlights, massive improvement with the relays fitted.YoursMark Link to comment Share on other sites More sharing options...
piman Posted November 28, 2011 Share Posted November 28, 2011 Hello Mark, all I will add is, ideally, fuse each filament rather than one or two fuses to feed the relays. The idea being that a fuse failure doesn't lead to total blackout?Alec Link to comment Share on other sites More sharing options...
RobMoore606 Posted November 28, 2011 Author Share Posted November 28, 2011 Thanks Mark I will look the other info up and consider tihs change.Big thanks to Rod who ppped up this evening, its amazing the difference another pair of eyes and hands can make.We were able to identify the fault was a short on a faulty number plate bulb holder.It was funny seeing the fuse glow RED ;D no idea why it didnt blow. Link to comment Share on other sites More sharing options...
junkuser Posted November 28, 2011 Share Posted November 28, 2011 Sufficient current to cause a cable to smoke, yet not blowing a fuse the current is being drawn through, certainly is difficult to explain.Makes one wonder if there was an alternative route in parallel to the fuse. Link to comment Share on other sites More sharing options...
RobMoore606 Posted November 28, 2011 Author Share Posted November 28, 2011 It sure does and when we tested the volts between the battery positive and the removed battery posisitive lead we got a reading of about 2.3 volts so there is some leaking volts in the harness somewhere, but at least I got lights and can drive again :) Link to comment Share on other sites More sharing options...
junkuser Posted November 29, 2011 Share Posted November 29, 2011 Would be wise to check out the cause for this Rob as, if there is a high resistance leak to frame, it could get worse, particularly if the present resistance is due to something that is capable of moving about.Maybe measuring resistance between isolated + terminal and frame and pushing wiring about/disconnecting things/removing fuses would be worthwhile to see what is happening.Do you have anything, such as a clock or alarm, that is permanently connected that could account for the 2.3V reading? Link to comment Share on other sites More sharing options...
piman Posted November 29, 2011 Share Posted November 29, 2011 Hello Rob, replace the fuse that glowed red, it has been overstressed and will not last long term.Alec Link to comment Share on other sites More sharing options...
junkuser Posted November 29, 2011 Share Posted November 29, 2011 roddymacp Posted today. " I noticed that I have a couple of exposed wires on the back of my old one almost a** though the sheath has shrunk back over the years."This is the type of problem of problem I had in mind when suggesting to check the back of the fuse box Rob. Link to comment Share on other sites More sharing options...
.thumb.jpeg.b15b81ef10abeea1c3039ae03c4a9f3a.jpeg)
Recommended Posts
Archived
This topic is now archived and is closed to further replies.