No High Beam - but there is voltage (and yes the bulbs are ok...)

Hey there,

Anyone ever seen it where there is 12V getting to the Bulbs on an '03 SV (on low and high beam when switched) - yet when switching to High Beam the headlamps just turn off!?

Yet when you stick the bulb into the cct and switch to high beam the voltage disappears on the pin connecting the high beam to the bulb...!?

I checked for continuity in the bulb and that's ok - and there is also continuity on the GND side of things...

Any tips?

My high bean has been playing up but the symptoms are slightly different.



I get bad grounds and the headlights feedback through main-bean. You get a dull headlight, and a dull tell-tale so I guess that doesn't help you!

My moneys on either a bad earth (ground) or corrosion in a multiplug. What happens is you'll get a voltage until a high current is demanded then the corrosion acts as an insulator, I've seen this on my older cars several times. I'd advise you to carefully check the wiring from end to end looking for verdigree (the green stuff that grows on electrical connectors) and clean this all off.

yeah I was thinking the same thing... I just couldn't see any...

I HATEEE electrical problems! they are just a bugger to find and sort out! (even being an electronics technician! )

Originally Posted by chris7231

yeah I was thinking the same thing... I just couldn't see any...

I HATEEE electrical problems! they are just a bugger to find and sort out! (even being an electronics technician! )

The grounds for the front lights are grouped behind the clocks - screen off and you should find them under the black plastic trim.

cheers mate, i'll have a look tomorrow after work...

Not sure if it's related but: the speedo has stopped working a couple of months ago too and also every 50% of time when i turn it on - the fuel pumps that prime the bike to start - do not 'prime' and i need to turn off the bike and turn it on again...

Ah now you're talking, almost certain the problems point to a common point. Check the accessory connection to the battery, make sure it's on nice and tight and pull then re-insert the fuses in the box to see if that makes any difference. Also go the other way, check the earth out as suggested by Simesb. This should be a walk in the park for an electronic's tech! BTW Have you got a wiring diagram and does the engine ever cut out?

yep - got the service manual... but the engine has never cut out...

Thanks guys for your help - I'll check it out tomorrow or this weekend... Bloody electronics - it's like plumbers always have crappy (excuse the pun!) plumbing and mechanics never drive Porches... Engineers always have crappy electronic issues at home!

Looks like your wires are wearing through. Mine did this then the other one went. After a search the wires had rubbed through on the subframe under the seat. Hope this helps only thing is mine is a curvy but I think the problem stands for pointys too