DIY LED Daytime Running Lights for the Miata NA

If you are like me, you've been noticing that a lot of new cars have really cool LED running lights - or DRLs (Daytime Running Lights). Well, they seemed like something that would look slick on a NA Miata. But could I do this myself? After some research, I realized it wasn't as easy as I first thought - 

• the parking lights/blinker assembly is a sealed unit - you can't just unscrew the lens and install a row of LEDs. 
• how to handle the blinker (directional indicator function)? Two rows of LEDs? Install another bulb for the blinker? Make the whole thing blink somehow?
• What about the emergency function? The lights need to blink without the key on.

Well, I noodled on it for a while and came up with this idea.

• Use single row of LEDs - as many as I could fit - that would span the entire parking lights/blinker assembly
• find the brightest LEDs possible, but not surface mount - go old school to simplify assembly
• for turn indicators, just blink the entire row using a relay hooked to the blinker circuit.
• Tie another relay into the emergency flasher to activate the LEDs.

The plan was to run a new wire to the LEDs that was switched 12v - on when ever the key is on. This will allow the LEDs to light whenever the car is running, rather than just when the parking lights are on. Because we want the LEDs to blink when the indicator is on, we connect it to the Normally Closed (NC) position of a relay (so the LEDs are lit when the relay isn't) and to 12v ground to the other side. The wire that would normally go to the blinker goes to one side of the relay coil and the other side goes to ground. This allows the relay to activate when the blinker turns on, opening the circuit to the LEDs causing them to blink. The parking light lead isn't connected since the LEDs will be lit whenever the key is on anyway. So there are a total of 3 connections on each side.  This all works fine when the key is on, but your emergency flashers need to work with the key off. I added another relay in from of the other two that switches the input to the flasher when it's activated. 

Just to summarize, In driving mode, the LEDs are lit. When the blinker is activated, the relay closes and opens repeatedly causing the LED strip to blink. Since both LED strips are independent, while one is blinking, the other side stays lit. When you hit the emergency flasher, another relay kicks in to power the LEDs.

I ordered a kit of 100 super-bright LEDs and resistors from Parts Express. They also carried automotive grade 12v relays, so I ordered 3 of those. I bought a Perf Board (a perforated sheet of plastic for building electronics) at Radio Shack to assemble the LED strips.

With all of the parts in hand, and a wiring plan in my head, I began the work.

Step One- assemble the LED strips

Find the perf board and the LEDs and resistors. Insert the LEDs into the perf board making sure you get the polarity the same for all -doesn't matter which way at this point, but make sure the long lead or flat edge of the housing is all pointing the same way. You want the LEDs as close to each other as possible to get the most LEDs in the housing - more LEDs = more light. I ended up laying the LEDs in the pref board at an angle and got 39 in the row.

Next install the resistors beside the LEDs. Don't share the hole with the LED so that you can twist the leads together on the back side. This makes for a solid connection and holds both parts in the board. You can angle the resistors so that they are tight to the LEDs, or lay them out vertically (this just makes the resulting  board bigger. If you angle the resistors you will run out of room at the end of the strip. I put half the resistors above the LEDs and half below to make the board as compact as possible. It doesn't matter which side of the LED the resistor is on.

Now flip the board over an twist the LED leads to the resistor leads making sure the the LEDs are polarized right (long lead on the same side). You can add another wire for the outside edge of the LEDs and resistors or simply flatten them into a long strip that will be soldered together later.

Trim the excess leads from the twisted connections and solder.

Apply solder to the bundle of leads or your new lead that runs along the outside edges.

This picture is actually from a couple of steps later,
but I wanted to show the twisted leads down the center
and the leads at the top and bottom soldered together.

Step Two - test the LED strips and fix any loose wires

Solder a couple one lead to the top leads of the strip and one to the lower. Make them longer than you need so you can test it. Find a 12v source to test with  - I used a electric tire pump that has a 12v cigarette lighter output. Take note of which are the positive and negative wires  and make sure every LED lights. If one is out, check the connections and resolder until they all light reliably. Do this for both strips/

Step Five - cut the strip to size
Your perfboard is probably too big to mount.  We want to cut it down to something we can fit into the flicker housing.  Mark the perfboard outside of the soldered area and give your self some extra room for mounting it to the wire retainers.  Cut the excess.

Step Six - dissect the parking lights/blinker assembly

We only need the lens for our LED blinkers/DRLs. Pull the two parking/blinker lights from the car by removing the two screws on each and them pulling out the bulb/socket assembly from the back of each. 

As you can see the lens is attached to the reflector with tabs on the plastic lenses and a gray adhesive filler.To deal with the tabs, we are going to cut the reflector side so that the tabs don't have anything to hold on to.I used a dremel to do this, but I'm sure there are other ways.

Next I removed the gray putty that glued the lens to the reflector.  For this I used a spray solvent. It turned the hardened putty into a soft gooey mess...

And after some prying with a large standard screwdriver...






The lens came loose.

After some scraping with the screw driver and a razor blade, it came pretty clean.

Step Seven - trim the ends of the lenses


The lens interlock with the reflector where they mount to the car. I needed to be able to reach the mounting holes on either side, so this interlocking bit needed to go...

First I cut either end of the section that needed to be removed...

Then "nibbled" the section off with a pair of pliers.

Step Eight - 

dead battery

Well, haven't had much to post about in quite a while. Generally I come home, plug the car in and in the morning I unplug it and drive it to work. Simple as that.

Tonight it wasn't so simple...
It was a misty morning so I drove to work with my driving lights on - not the headlights, just the driving lights - it wasn't dark, or rainy just a little misty. So I park in the lot in plenty of time for my 9:00 meeting and at when I return to my car at 6:00 - nothin'. No dash lights, no familiar thump of the contactor, just nothin'. At first I wasn't sure what had happened, then I noticed that the light control was still on - the battery was dead. Without the 12v battery, the contactor won't close, the controller won't get operating voltage, nothing will work.

Now I sat for a minute and remembered something... When I first built the car I had the DC/DC converter connected directly to the pack, but it was constantly charging the battery and draining the pack, so I put in a relay so that the DC/DC converter was only active when the key was on. Now there was a small mechanical switch on the side of the relay that allowed you to activate it manually, I knew if I could get the relay to close, the DC/DC converter would provide the 12v needed to get the car to work.

I popped the hood and unscrewed the cover of the High Voltage Enclosure to access the relay, With a flash light I checked either side for the switch - there it was on the driver side - just below 2 high voltage leads. I   turned the ignition key on then dug a pen out of my laptop bag thinking it would safely flip the switch, but it wouldn't reach it. I thought about it for a minute, but I knew I had to use my finger to do this. I put my left hand behind my back (an old trick I learned from a TV repairman - you don't want to touch ground with your left hand when you get a jolt on your right and have the shock pass through your heart...) and with my right index finger reached between the wires and pushed the little plastic tab in.  It made a satisfying clack as the relay closed and the 12v from the DC/DC converter kept it that way.

I closed the hood and got behind the wheel. Everything looked normal now., As I turned the key into the start position I heard that familiar thump of the contactor and we were mobile.

It was dark and with the headlights on I knew eventually the 12v would drop pretty low and the controller wouldn't like it - maybe enough to stall out - so I took the streets home. Sure enough, about a mile from my door the "Check Engine" light came on solid but she continued to drive fine. I got her home and safely into the garage.

I can't think of another car that will start with a completely dead battery. I've compression started a lot of cars, but never with the battery completely dead. Even the old crank-start cars needed a battery for ignition, right? These electric cars are somethin' aint they?

Cool electric car decals

Been looking for some good EV stickers for my electric Miata, but all the stickers I found were from the 90's and quite dull.

One winter I came across some cool lightning bolt graphics at a ski shop. Comes out they were from Electric Sunglasses. A little research and I found some stickers that clearly said "electric", were cool and didn't break the bank.

  

If you want to get some for yourself, just send me a comment and I'll pass along the URL.

Miata "hood" alignment

I see a lot of Miata's with hood problems - or at least that's how they look. You know the ones, where the hood sticks up higher than the pop up headlights. I always wondered how the hood got that far out of alignment, but that's not what's rong at all.
After doing a lot of under hood work I found my car exhibited the same hood issue. But I wuickly found out that it wasn't the hood at all, just the headlight covers...

 There isn't any bracing in the back of the Miata headlight covers. Any pressure will cause them to bend down creating what looks like a hood alignment problem. Luckily, the fix is really simple...

Prop open the hood, grab a rag and "love up" the underside of the headlight covers. Apply a little upward pressure as you rub across the width of the cover. Don't pull hard, just  gently pressure is all it needs.

 In no time your headlight covers will be back where they belong and your hood will fit like new.

$8 Fix for a faded Miata bumper

If you have an early Miata with original paint, chances are the front bumper has faded. You have probably read about different polishes or treatments that should work, but none worked on my car. Here's how the nose used to look - tired and faded...

Then I got the idea that what was really wrong was that the clear coat was gone. I tried a little cear touch up paint to test the ides, and it worked! I went to the local auto parts store and bought a can of Duplicolor clear for $8. I masked off the metal work, so that only the rubber bumper was exposed and laid down 3 coats of clear before the can gave out.
Here is the result:

 

After a couple of days, I rubbed it in with some polishing compound to bring out the shine and there you have it. No need for an expensive paint job and no more embarrassing faded nose - and for only $8!

Miata can't shift into reverse?

About a year ago, I was driving my '92 Miata and I couldn't find reverse gear. I made a couple of simple fixes and, so far, I haven't had any trouble with reverse since.

Here's a tip or two if you find you can't get your Miata into reverse:

If you have trouble shifting into reverse with the clutch fully engaged, try giving the car a little throttle while you release the clutch AND pull the shifter into reverse.  You may feel the gears start to grind a bit, but it will often slip into gear.

If that doesn't work, you can replace the reverse light switch and replace your transmission fluid with synthetic. I'm not sure which of these made the biggest impact since I did them the same day, but neither of them are expensive or hard to do.

• Replace the reverse light switch  Reverse lights are often a trouble spot for NA Miata's. Either the switch fails or the connectors  to the switch work their way loose. The reverse switch can also become stuck which may prevent you from shifting into reverse. This may have been the problem with my car, since the shaft was hard to depress and felt like it was worn into place. It's really not too difficult to replace the switch itself, though make sure you reinstall your old washer. Without it the switch will protrude into the transmission a little too far making matters worse!. Replacing the switch isn't hard, but connecting the switch it IS. The wiring is on top of the transmission (!) making it quite a chore to connect. Luckily, they aren't polarized, so either wire on the harness can go to either wire on the switch - but that's small consolation.
  Check out the red wires on the left side of the transmission in this picture from Hakuna Miata. They head up and over the transmission to the right side where they are connected to the harness. Fun eh? As an added safety measure, I would recommend taping these connectors with some duct tape after they're connected. You don't want to do this again...
  
  
• Replace your transmission fluid with synthetic. Synthetic oil is much slipperier then the run of the mill stuff, which makes the transmission easier to shift and could improve your mileage as well. You'll want to refill the transmission with the car level so that you can get an accurate read on how much synthetic is in the gear box. Jack up both ends of your car and make sure you have enough room to work. You can get synthetic at most car parts stores for under $10, and while you are there you may need to pick up a couple of other things
  - My filter plug used a square drive - which was not in my toolbox - so add that to your shopping list if you don't have one.
  - Spray solvent.  My filler plug would not come out for anything and the usual WD-40 did nothing. Comes out the last person to open it (or maybe it was the factory?) gooped it up with a lot of thread lock. A little spray solvent did the trick.
  - A fluid pump.  You'll need a pump to get the fluid in the transmission, since the filler is too close to the tunnel for the bottle to fit.
  - The Synthetic transmission oil. The manual says 2.1 quarts are needed, but I used a little less than 2 and spilled a bit as well. 

After I made these simple changes, shifting was noticeably improved.  And in the past year, I never had a problem shifting into reverse again. Hope it works for you.

Blame the potholes

Before you read the following post, you should know that I drive this car daily.
It may seem that this blog recently is nothing more than a list of  problems, but when the car works (which it does 99.9% of the time) there is nothing of any interest to post - "disconnected charge cable, backed out of garage, drove to work, drive home from work, connect charger cable..."

Yesterday I had a little trouble getting to work. Along the way my controller appeared to shut down - the Charge light went out and the Check Engine light went on plus, I had no power. I coasted to a stop and restarted the car. Everything worked fine. I took the streets to work in case it decided to fail on me again and once I parked at work, I hooked up my laptop to my Zilla to read the error codes. There were 3 of them - the 12v supply was too low, the contactor opened unexpectedly, the motor RPM was too high. Sounded pretty serious, but I remembered a similar set of errors when my 12v SLI battery failed and I had left the door ajar one night, leaving the interior lights lit for 14 hours... I decided the SLI battery was to blame and after work, took the streets home without incident. Once back home, I hooked up my 12v charger to my SLI battery. It showed it was at 100% - but I ran it through a charging cycle anyway.

Next day, I drive to work without incident. Ont the way home, however, it stalled, First on the freeway (i was able to coast down the next exit where I was able to restart it), then at a left turn (sorry to the people behind me) then at a traffic light (more sorries to those behind me).

I figured it must be a loose 12v wire. Saturday I popped the hood and poked around for a loose wire. Everything looked fine...until I noticed the ground connection under the relay box was loose. I tightened it up and took her for a test drive - all good. A simple fix to what sounded like a serious problem.

The potholes must have rattled it loose.