Headlight motor diodes

[al 350i]

Could someone please give me a guide on how to replace diodes on the headlamp motors and what/where to get them?

Car is a 1987 350i, my diagnostic is as follows:

Lights off - 12v yellow/white going into motor
Turn lights on - Headlamp motor control relay switches, 12v purple/white going into motor
Turn lights on - No power (12v) returning back to relay from motor via purple/blue wire (LH) and no power returning back to relay from motor via black/red (RH), relays can't be energised hence no pop.

Both lights will come on dip/main and both light pods will lift/power motors if 12v applied to purple/blue & black/red on back of relay board (was expecting both to be purple/blue wire as according to wiring diagrams!) so guessing no breaks in wires.

My conclusion is that one or both or all diodes are causing issue, wedgengineer pages have been very helpful but just need a little guidance on how to change diodes and which ones, unless I've got something wrong and someone has a better idea :-)

[Penelope Stopit]

Here you go http://www.tr7triumph.com/forum/viewtopic.php?t=24...

Good images and a diode part number

Any 1 Amp or above standard diode will do the job

On past experience would never again replace the diodes in the motor, would remove diodes, solder in links in place of diodes then fit diodes inside vehicle close to relays, wiring would be added to suit

Could be dirty contacts or diodes faulty

Confusing that both lights should fail at the same time, perhaps they didn't???????

[al 350i]

Thanks for link.

I just assumed if one fails it stops both working, my electrical knowledge isn't the greatest and I don't fully understand most of it but can follow instructions, took most of yesterday afternoon to get this far, although did fix boot release while I was at it :-)

[Penelope Stopit]

As the diagram shows, LH relay and motor, RH relay and motor