Flash Those Headlights

By Pete Adkins. From an original article on www.miata.net

Mazda seem to have lost the plot on whether or not to build in a facility to pop up the headlamps when you flash the full beam on Mk1 cars; some don't have the facility at all, some do, but the headlamps stay up for a few seconds before dropping down.

When I bought my '91 a year or so ago, I actually reported it as a fault to the dealer, assuming that this would be a feature of the car ! Not so. There is a solution for all you flash-less owners out there; I've 'borrowed' this from the Miata web site in the states. If you want to have a look at the original, the address is http://www.miata.net/garage/flash.html

So here's the article, re-hashed for UK cars. (My apologies for any copyright infringement, nothing on the page to say it can't be copied & distributed, so I have !)

Since a picture speaks a thousand words, I've also included a photo of the diode in place in my car at the end of this document.

.oO---Oo.

This is how to get a "flash to pass" feature on '93 and earlier MX5s. '94 and '95 models implemented an inferior system from the factory that keeps the headlights up for 3 seconds before lowering them.

You need a 2.5A high current diode. Tandy stopped selling components a long time ago, so the best source is probably either Maplins (http://www.maplin.co.uk), or try Donutz, who will also provide full instructions ! (http://www.donutz.co.uk)
Squirm your head down under your dash and find a big white connector (some MX5s have a different colour connector) shaped like this:

Bend both leads close to the diode (cutting is not necessary) to form a |_| shape.
Locate the Red with White stripe wire and the White with Black stripe wire. Now I discovered that the wiring loom on my Eunos uses a different colour code to this US one, and I assume it's likely that UK cars will also use a different colour loom. So long as you go by the connector positions, you shouldn't have a problem.
Push the ends of the diode into the connector next to the wires with the diode's white stripe sticking in next to the White/Black wire. It should go nearly all the way in and make contact with the metal parts in the connector.
Test by pulling on the bright light switch. The headlights should go up, flash, and go back down!

There's another, and in my opinion easier location to fit the diode, that doesn't require you to be a contortionist;

Go to Tandy and buy a 2.5A high current diode. (3 cost about £1.50, part number 276-1114)
Remove steering column cowl (four screws - all on the bottom of the steering column).
You will see 2 connectors going to the turn signal/light combination switch. Remove the long, thin white connector - this will give you access to the smaller black one. From the wire side, the black connector will look like this:

           ----------------
           |              |
     -------------        |
     |G/O|W/R| * |        ----#|###---|   <- 2500mA diode
     -------------                    |
     |W/L|R/B|R/W|                    |
     -------------                    |
               |                      |
               ------------------------

Locate the Red with White stripe wire and the White with Red stripe wire (don't be confused about this! Again, wiring loom colours may vary - go by the wire position in the connector)

Bend the diode into a square U.

Push the ends of the diode into the back of the connector so the diode-end with the with stripe is next to the white with red stripe wire. (Got it?) Make sure it's snug. The diode leads bend easily so be careful. You may want to remove the black connector to make the task easier.

Replace the connector(s) and give it a try! Pull on the bright light switch. The headlights should stay up for as long as the lever is pulled.

Replace the steering column cowl.

This is a photo of the diode in place, although the connector isn't plugged back in yet;

If your lights don't pop up when flashed, then one of two things has happened; either the diode is between the wrong wires, or it's the wrong way round. If it's the wrong way round, it may have got very hot - so be careful when pulling it out.

If you're unsure, get hold of a multi-meter or a 12V test light. What you're doing is connecting together the feed to the headlamp motors and the main beam supply. Identify each of these, & there you go. Having said that, I used the second method, spotted the wire colours were different & went by position. It's easier this way, as the connector plugs into the steering column, and so you don't have to decide which side of the connector the diagram represents. There's an un-used pin, so it's easy to identify the right wires - go for it !

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