Headlight switch replacement on BN7 or BJ7 cars

[RDKeysor]

I'm just learning my way around this car--I last owned one in 1963--and recently discovered the headlights aren't working. The switch has no feel at all. I have been told that I can can shut off the battery and connect a jumper cable across the switch poles (I'm assuming there are two). Switching on the battery should turn on the lights, confirming that the switch is bad. Ditto I can hook up my faithful test light across the poles to determine if I have power there. Initial examination tells me that this under-dash area is going to be difficult to access. First, I need to know how to detach the pull knob on the switch. I then assume I can remove the exterior nut and push the switch through the dash, pulling it down where it can be worked on and/or replaced. Looking ahead, do any of the usual parts dealers, NAPA, PEP Boys, etc., offer the 35 and 50 amp fuses these cars require? My recently sold Jag Mark 2 used a traditional 50 amp fuse, and I believe I had to get those through a Jag parts specialist. Thanks for all of the help I have been given as a rejoin the AH fraternity as a senior citizen.

 

[DerekJ]

If the light switch knob is an original type it will have a small hole in the bakerlite underneath on the barrel part. Insert a small drift and push down on what is a small ball on a spring. Its this that prevents the switch from pulling off the metal bar. At the same time lightly pull the switch to ease it off. Then unsrew the ring and extract the switch for examination.

 

[andrea]

There are one very good repair PDF for our Headlight Switch
https://www.lotus-europa.com/manuals/misc/electrical/head_sw.html
this switch suffers from one bad conceptual system design, and have one hard work especially if you have the 50/60 w lamps
I have one NEW (India?) but I have preferred the oldest original on my car, quality are very low
Dismounting the switch, if you find signs of burns on the contacts,
value seriously the possibility to turn your light system to a Headlight relay system
it drops drastically the electrical charge and the heath of the switch, and it work well, if it NOT have mechanical defects

 

[RDKeysor]

The PDF Andrea offers is like my headlight switch is only in the most general way. That one came from a Lotus and disassembles a bit. Mine does not come apart without knocking out the two rivets that also attach the set screws for the wiress. I have the switch out and will test it tomorrow. I did learn that it has two stops as it pulls out, the first I assume for the "parking lights" and the second for the headlights. I don't think I recognized that there were two stops, so I have to check that out. Frankly, the switch looks pretty good, so that may not be the problem. Thanks all.