Discussion
Well, still haven't resolved the wiper saga but now have a situation, probably caused by me interfering, where I have high beam or high beam, no dip beam. So it's back under the dash to the relays, check the fuses and then look at the column switch. Hada quick peek last night at the switch but tire and late.
...Yes the lights should work with the Dip/Main switch unplugged; no they shouldn't be stuck on Main beam.
Here's a quick PaintShop butchery of the lights wiring diagram:
Assuming the Dip/Main switch is unplugged, there's nothing to stop the main lights switch from working. So it supplies 12V to the coil of the Headlamp Motor Lift relay (1) which energises to allow the pods to pop up (using the Headlamp Motor Control relay at 2a, but we can ignore that for now).
When the relay at (1) energises it sends 12V (2) to the control diodes at (3).
Diode D1 conducts to apply 12V to the coil of the Headlamp Control relay (4a) which energises and sends 12V feed to the Dip/Main relay (4b).
Normally this would be de-energised so this 12V feed passes through the relay's normally-closed contact and supplies the dipped beams.
However, if diode D2 (or D3 if fitted) was short-circuit and conducting both ways, it would allow the feed at (3) to reach the coil of the Dip/Main relay (4b). This is normally only energised by the Main beam or flash switches.
With the Dip/Main relay energised, it changes over and feeds the main beams instead of the dips... and it'll do this as long as the main lights switch is on.
To prove it, find the diodes (usually on or about the relay board), note the orientation (usually has a white band on one end) and unplug.
A short-circuit diode will measure zero resistance either way round on a multimeter.
Edit: typos. 'deef', instead of 'feed', FFS
Here's a quick PaintShop butchery of the lights wiring diagram:
Assuming the Dip/Main switch is unplugged, there's nothing to stop the main lights switch from working. So it supplies 12V to the coil of the Headlamp Motor Lift relay (1) which energises to allow the pods to pop up (using the Headlamp Motor Control relay at 2a, but we can ignore that for now).
When the relay at (1) energises it sends 12V (2) to the control diodes at (3).
Diode D1 conducts to apply 12V to the coil of the Headlamp Control relay (4a) which energises and sends 12V feed to the Dip/Main relay (4b).
Normally this would be de-energised so this 12V feed passes through the relay's normally-closed contact and supplies the dipped beams.
However, if diode D2 (or D3 if fitted) was short-circuit and conducting both ways, it would allow the feed at (3) to reach the coil of the Dip/Main relay (4b). This is normally only energised by the Main beam or flash switches.
With the Dip/Main relay energised, it changes over and feeds the main beams instead of the dips... and it'll do this as long as the main lights switch is on.
To prove it, find the diodes (usually on or about the relay board), note the orientation (usually has a white band on one end) and unplug.
A short-circuit diode will measure zero resistance either way round on a multimeter.
Edit: typos. 'deef', instead of 'feed', FFS
Ian
THank you very much for all this
The very short blue wire that was in the side of the wiper delay relay is in fact the diode. Having taken it out to examine it, I put it back "upside down"
Still not sure why the wipers are not right and puzzled as to this delay relay in a loose holder, why is it not part of the board. Or is it somethig else.
THank you very much for all this
The very short blue wire that was in the side of the wiper delay relay is in fact the diode. Having taken it out to examine it, I put it back "upside down"
Still not sure why the wipers are not right and puzzled as to this delay relay in a loose holder, why is it not part of the board. Or is it somethig else.
Gassing Station | Wedges | Top of Page | What's New | My Stuff