converting to quartz/halogen lights

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Posts: 159
Joined: Sat Jan 12, 2019 6:16 pm
First Name: Rod
Last Name: Letcher
Location: Eugene OR
MTFCA Number: 32097

converting to quartz/halogen lights

Post by Loftbed » Fri Mar 01, 2019 1:59 pm

I am converting the 1915 headlights to Brass 1913 headlights with the quartz/halogen conversion pieces from Chaffin. (see 1st photo.)
Is the Diagram the correct wiring? (second photo).

The original wiring used the blk and white wires from the switch wired directly to the bulbs (internally grounded?)
When I tried wiring the Blk and white wires to the two wires from the quarts/halogen bulb I got nothing. Then taking one of the quartz wires to ground resulted in light.

Sorry for stupid question, but I'm an electrical moron of the highest order.
wire headlights.png
13 Model T Speedster
38 MG TA
57 Ford Thunderbird
1952 Jaguar XK120s FHC
1928 Buick 24 "Sport Roadster"

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Re: converting to quartz/halogen lights

Post by ewdysar » Fri Mar 01, 2019 3:06 pm

Hi Rod,

My ‘15/‘16 has mag headlights and the headlight switch is on the firewall to the right of the switchbox. There is only one wire to the lights with no dim/high switch. The headlights are dim at idle and get brighter as engine rpm increases.

The dim/high switch and wires in your diagram are intended for bulbs with two filaments, one for dim and one for high, as installed on the later “electric” T’s.

You new halogen bulbs are built for one setting only, therefore, 12V to one of the wires and the other wire to ground. You can wire both wires from your switch to the + wire on the halogen setup. If you do that, the headlights will be on regardless of whether you have the switch set to high or low. But with either position, the headlights will look the same/produce the same amount of light.

Keep crankin’

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