Headlamp problems

[Chubster]

Hi, my headlamps seem to have a mind of their own, however before I start I have already replaced the loom all the relays, the Pektron unit and have different headlamp motors. But they are in opposite phases when one is up the other is down and they stay in that phase whether the lights are on or off and also when the flash operates.... Any ideas?[8D][8]

DSC01653.JPG

[jclay (RIP 2018)]

Yes, your car is possessed!

Actually, it sounds like you have some wires reversed on the contact strip or have some bad diodes.

[Chubster]

Thanks Jclay, I will try this and get back if it doesn't work. I was thinking in having it exorcised but then somebody just said is was British Leyland build quality so I needn't bother!

DSC01653.JPG

[bmcecosse]

Yes - must be crossed wire. Try just one light - disconnect the other completely - and forget about the 'flash' for now. Obviously - when the lights are switched on the lamp should rise, and fall again when switched off - get one to do this successfully and reliably and then work on the other one ! I find mine work ok when the engine is NOT running, but when running the volts are higher and the motors sometimes 'run through' the stop point when switching off and the lights start winking!! Answer is to pull over and switch off the engine - then switch off the lights, and down they go.

[Chubster]

OK next question... I have double checked the relays and as I have a few spare checked them they are OK, I have checked voltage on the wiring and it is the same both sides with the corresponding wire. I have checked the diodes for open circuit and they are fine. BUT now the passenger side works fine as before but the drivers side does not work at all unless you use the manual knob when the motor cuts in does one complete circuit and stops (in the down position). Any ideas please.......[8D][8]

DSC01653.JPG

[bmcecosse]

Still think wires reversed somewhere - maybe at the relay ?

[TR Tony]

If the run/stop relays check out then could this be a faulty limit switch on the drivers side?

Sounds like you have already checked the diodes but what about the contact strips in the switch & the wiring connections? Don't forget the limit switch is part of the control circuit so if for some reason the current is not passing through the switch to the run/stop relay then the lamp motor won't be activated.

When you start to move the motor by hand you may be making a contact so that the motor kicks in but if the limit switch is faulty it may not be stopping the motor which then just runs a complete circuit back to closed?

Well, that's my theory anyway ......

Tony

<font size="1">1981 2L FHC Cavalry Blue - very original & not rusty!
1980 3.5L V8 DHC Regency Red - on the road again.</font id="size1">

[Chubster]

Cheers chaps will try both of these and report back[:D][8]

DSC01653.JPG

[Chubster]

OK next question..

I took the headlamp that worked correctly and swapped it with the one that didn't work and it worked. Therefore the fault lies within the headlamp motor so I took that unit apart (just the wiring box) and checked it against the wiring diagram it matched. so I checked the diodes and they are OK showing 0.6 and 1 when measured with the multimeter. But still that specific motor does not stop it just continues to move until you disconnect the power...............Any ideas?[:D][8D]

DSC01653.JPG

[TR Tony]

I would say the contact strips in the motor limit switch are not working correctly.

Even if the diodes are Ok, the contact strips need to to be clean & making proper contact as the motor rotates to initiate the run/stop relay.



Tony

<font size="1">1981 2L FHC Cavalry Blue - very original & not rusty!
1980 3.5L V8 DHC Regency Red - on the road again.</font id="size1">

[bmcecosse]

It also needs a little mechanical resistance as it reaches the end of travel - to alklow the 'dynamic braking' to do it's job, so try adjusting the stops in a little.