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dip switch question

Jim_Newman

Jedi Hopeful
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' anyone know the actual current <span style="font-weight: bold">rating </span>for the dipswitch (dimswitch)on a MK1?
As always, thanks.
Cheers
 
Hi Jim,

What is the reason for your question?

Although I can’t tell you the amperage rating for your Mk I dipswitch, I can hypothesize that it would be greater than 80-watts with approximately 11.1 Amps flowing through the headlight switch to power your lighting systems. When taking into consideration the extremely thin gauge wiring of the original headlight system, I would not recommend adding electrical demand on your 50 year old dipswitch or light switch without adding relays and upgrading your wiring to carry the real amperage from the relays to the units to be powered. This action would allow your dipswitch and light switch to be used for relay activation with minimum amperage flowing through their contacts.

All the best,
Ray (64BJ8P1)
 
Ray:
A few months ago, in the fashion of "healeypassion", I changed the floor mounted dipswitch for a dash mounted toggle. (The overdrive toggle switch had long ago been moved to the gear shift knob). I selected a toggle switch with a current rating of 20Amp and when I bench tested the setup it seemed to work fine. I had not driven the car in the evening for some time and when I did recently with the headlights on, my daughter, who was in the passenger seat, enquired about the smoke coming from under the dash. I told her that it was typical of old British cars but she didn't buy it. In fact, upon inspection, it appeared that the electical tape around the toggle connection was melting! We finished the short remaining part of the trip with no headlights.
This led me to beleve that the switch was not of sufficient capacity to handle the current. So the question really is, what now? Could I employ a relay and what kind of relay would I use and how?
In the meantime, I have discovered that I now have no tail lights or license plate light (though the directional signals and brake lights still work). The difficulty with the dipswitch and tail lights may be coincidental but perhaps it is a related problem. Any thoughts out there? The wiring harness was newly replaced about 10 years ago.
As always, thanks for the advice.
Cheers
 
In fact, upon inspection, it appeared that the electical tape around the toggle connection was melting! We finished the short remaining part of the trip with no headlights.
This led me to beleve that the switch was not of sufficient capacity to handle the current.



That seems like a reasonable conclusion JIM-- :laugh:

So the question really is, what now? Could I employ a relay-YEP- :yesnod:

what kind of relay would I use: Those small 30 AMP Bosh relays are nice. and how?

There are schematics to accomplish this in:
Norman Knocks Healey repair books one of the circuits I have sent to you via E-Mail.. However, my advice is to let the dip switch alone put it back like it came.

In the meantime, I have discovered that I now have no tail lights or license plate light (though the directional signals and brake lights still work). The difficulty with the dipswitch and tail lights may be coincidental but perhaps it is a related problem.--Yep it is.
------------------------------------Keoke
 
I moved the dip switch to the dash in place of the OD switch. Like you, I have the OD switch on the knob. I used relays. Not only does it reduce the load on the switch, it makes the headlights brighter and the driving/fog lights also work in conjunction with the dip switch.
 
John,

Did you upgrade your wiring between the relays and the headlight plugs? The standard gauge to the headlight plug is rather thin and I would recommend increasing the gauge if you are upgrade to Halogen or better lighting.

All the best,
Ray (64BJ8P1)
 
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