I would contact Ed Nantes, in Australia: I’ll bet he’s done something like this.
Hopefully, he might see this, Paul!
1 Like
Hi Chris,
I’m away from home for a few weeks so I don’t have access to my car or P100 lamps but I did convert them for double solenoid dipping. The thing to remember about the solenoids is that they have two windings. One drawing a high current to activate the solenoid and having activated the high current winding is switched off and a lower current winding acts simply to hold the solenoid in the present position. (Sorry, looking at the diagram my description is not quite right. The high current and low current windings are in series and the low current winding is shorted out during the initial activation but having activated, the shorting switch is opened leaving both windings operating but now with lower current.)
As to the wiring, use the scheme shown here:
When I first got my car it was arranged for single dipping in which only the nearside lamp dips and the offside lamp is extinguished when dipped.
My non-dipping reflector was pivoted but was held in one position my a single small screw in the rim. After removing the screw it now dipped but required a light return spring as fitted to my dipping lamp.
HTH
Peter
That’s very helpful, Peter - many thanks! I think I’ve worked it out now. I only need to concern myself with the side that the 7 wire goes to, as that is the solenoid for dipping the reflector. The other side with the 9 wire concerns the headlight bulb and must be to do with extinguishing the opposite headlamp when on dip.
On the P100 I’ve been playing with, the headlamp wire comes into the separate junction box, and carries on to the bulb from the terminal opposite. I’ve tested the junction box in case there are any odd internal connections, but the 3 terminals on one side just connect with the 3 directly opposite.
I will need to run a wire from the dip switch to the new solenoid on the headlight that previously just went out on dip.
I THINK I’m on the right track… I’ll have a look at the the solenoid that’s already on the car tomorrow.
For driving in the USA, I removed and remounted the reflector to the horizontal set of mounting holes Lucas provided in the outer shell, so now the dip is straight up and down.
Looks rather different to the P100, but glad to see the 6 amp fuse!
Do you mean the mechanism is different?
I suppose there were variations, but I thought mine were also P100s.
This may be the answer, different model P100s.
The SS 2-1/2 L used the 505,330 dipping reflector so it must be a P100R.
Perhaps Rolls used the 501,400 so perhaps a P100S? An extra 26 shillings 3 pence.
Here is the inside of both R100 lamps on my car. LH (nearside) one has the solenoid, and it worked once I put a fuse in! RH one has all the bracketry, but no solenoid as yet.
I’d like to find single filament LED bulbs with positive earth that will fit, but I’m not sure there is such a thing. Better Car Lighting (Quicksilver) only seem to have a twin filament one in a negative earth version.
Hi Chris- need to speak to the crowd at classic dynamo and regulator conversion, Lincoln
They have helped me with my positive earth leds
1 Like
I purchased a solid state (original appearance) voltage regulator from them for my XK120 - I highly recommend them.
1 Like
Very interesting article, Peter - thanks for that! I’ve just been on the phone to Gil Keane at Better Car Lighting and he told me that they now do a single filament BA20S LED bulb for the P100/R100 lights with dipping reflectors, so I’ve ordered a pair. Also the flashing conversion for the trafficators.
Quicksilver Automotive - BA20S LED single beam bulbs Pair
Chris
That’s interesting about the BA20S LEDs Chris.
Thanks,
Peter