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Grizz1963 · 04-05-2022, 03:13 AM

Regarding the lighting.

Some replies below, from RetroRides

[quote author="@flingstam" source="/post/2726206/thread" timestamp="1649060375"][quote timestamp="1649058376" source="/post/2726200/thread" author="@foxmcintyre"]Does the MX5 use a negative trigger rather than a positive? Some Japanese cars had one 12V feed and 2 switched earths to operate the filaments in the bulb. That config won’t work with LED lamps, worth double checking that. [/quote]Rich has hit the nail on the head here. The MX-5 does indeed use a switched ground/earth to operate the headlights. However, at least one light  (dipped or main) should come on if there is power going through. 

This video may be helpful. It's not perfect, because he's swapping H4 halogens for separate high and low beam bulbs rather than LEDs, but he explains the wiring situation pretty well:

[video src="https://www.youtube.com/watch?v=zxJbmIKp2KM"][/video]

This is exactly the issue I had with the Deliboy, and I solved it by buying a plug and play link harness from eBay, which included an additional power feed from the battery, and standalone relays. Of course, it did take me two attempts, as the first one I bought wasn't for a switched ground circuit. Caveat Emptor, and all that. 

[a href="https://forum.retro-rides.org/thread/215030/1991-toyota-deliboy?page=7"]The Deliboy Story[/a]

(Pages 7 and 8 of the thread contain all my headlight-related adventures).[/quote]

04-05-2022, 03:13 AM	#5603
Grizz1963 Registered User Join Date: Dec 2012 Location: Rochester, KENT Posts: 10,492	Re: Grizz's Redneck Express 1966 Chevy Short Fleetside RESTO-GO! Regarding the lighting. Some replies below, from RetroRides [quote author="@flingstam" source="/post/2726206/thread" timestamp="1649060375"][quote timestamp="1649058376" source="/post/2726200/thread" author="@foxmcintyre"]Does the MX5 use a negative trigger rather than a positive? Some Japanese cars had one 12V feed and 2 switched earths to operate the filaments in the bulb. That config won’t work with LED lamps, worth double checking that. [/quote]Rich has hit the nail on the head here. The MX-5 does indeed use a switched ground/earth to operate the headlights. However, at least one light  (dipped or main) should come on if there is power going through.  This video may be helpful. It's not perfect, because he's swapping H4 halogens for separate high and low beam bulbs rather than LEDs, but he explains the wiring situation pretty well: [video src="https://www.youtube.com/watch?v=zxJbmIKp2KM"][/video] This is exactly the issue I had with the Deliboy, and I solved it by buying a plug and play link harness from eBay, which included an additional power feed from the battery, and standalone relays. Of course, it did take me two attempts, as the first one I bought wasn't for a switched ground circuit. Caveat Emptor, and all that.  [a href="https://forum.retro-rides.org/thread/215030/1991-toyota-deliboy?page=7"]The Deliboy Story[/a] (Pages 7 and 8 of the thread contain all my headlight-related adventures).[/quote] __________________ MY BUILD LINK: http://67-72chevytrucks.com/vboard/s...585901]Redneck Express - 1966 C10 Short Fleetside MY USA ROADTRIPS http://forum.retro-rides.org/thread/...2018-humdinger IF YOU CAN'T FIX IT WITH A HAMMER, YOU'VE GOT AN ELECTRICAL PROBLEM MATE.