Head Light Wiring Question
 

I'm "rewiring" my car (cause racecar I'm stupid).

My issue is that I'm getting the same exact amount of light at Low beam and at High beam.

What I've done...
For the headlights, I'm wiring in a new 3 way toggle switch. The idea is Low, Off, High. To start...Here is the headlight wiring diagram for a 99 NB. (I'm gonna reference the colors)

https://cimg2.ibsrv.net/gimg/www.mia...b8b0aab10c.jpg

I have wired the following to each post on the switch...

Low -> RED, RED/YEL, LT GRN
Off -> GROUND
High -> WHT, RED/YEL, LT GRN

And here is the light output (both high & low look identical)

https://cimg2.ibsrv.net/gimg/www.mia...42bb6a16f5.jpg

The other thing that looks odd to me. The RED wire (low beam) is thicker than the WHT wire (High Beam). I believe the RED is 14 gauge (or the metric equivalent) and WHT is 16 gauge. I would think you would have the heavier gauge wire on the High beam. You can tell in the picture below they are two different gauges.

https://cimg3.ibsrv.net/gimg/www.mia...ec47ded581.jpg

So any thoughts on what I did wrong? (Or am I just blind and can't tell the difference in light output.) Any thoughts on why the low beam has the higher gauge wire?

My only thought is that I need both RED & WHT on the High post (so they are both grounded) when I'm using High Beams, but the wiring diagram doesn't say to do that?? (or does it...I'm not an EE, so I could easily be missing something.)

Thanks for any assistance!

Are you sure that is not the red/yellow power wire that is bigger?

You should have a switched 12V on the RED/YEL and GRN (which are your heavier gauge wire), high / low beams are controlled by grounding the other two wires through the column switch. If you have a multimeter or even a test light you can confirm what's what for the wires on your car.

Hey Metal Muffins,

Thanks for the reply. Fairly positive we are talking about different RED/YWL wires. The RED/YWL wire (along with the LT GRN) are the grounds to the switch side of their respective relays and are 20 gauge wires carrying low voltage. The RED/YWL and GRN that I believe you are talking about are going straight to their respective headlight from the fuse box. I have not touched either of those wires.

Here are all the Headlight Switch & High Beam Switch wires that I'm asking about. The Yellow wire I added, it's the ground wire, and the other two are the RED & WHT wires.
https://cimg5.ibsrv.net/gimg/www.mia...225e6d0ac1.jpg

I also no longer have a column switch, but I'm fairly certain I have the relays powered correctly, otherwise I wouldn't be getting any lights to work. (& they all work, I just don't seem to have any difference in light output between high beam and low beam)

All my switches are here now...
https://cimg0.ibsrv.net/gimg/www.mia...14fe9b4ec1.jpg

This is the back of the switch...(My wire colors aren't the same here because it's the pigtail, but they are the same as you see here.)

Low -> RED, RED/YEL, LT GRN
Off -> GROUND
High -> WHT, RED/YEL, LT GRN
https://cimg1.ibsrv.net/gimg/www.mia...f829699a2f.jpg

And here is a shot a bit further out...you can see I have all the wires in the pigtail testing them.
https://cimg4.ibsrv.net/gimg/www.mia...de1722a809.jpg

Not sure if the above pictures help any or just make it all more confusing.

I also chose to redo my entire car not too long ago, and hopefully could chime in with some help.

While I am not exactly sure how you have your switch wired currently, I believe your wiring is backwards.

Firstly, the RED/YEL wire from the headlight switch activates the headlight relay when grounded. This wire needs to be grounded anytime you wish to turn on EITHER the Low or High Beam circuit. When the relay is active the BLK/BLU wire brings power through the RH and LH headlight fuses to each headlight. Power should be GRN and RED/YEL respectively.

In order to turn on the Low Beams the RED wire (indicated by the arrow in the bottom right hand part of the picture should be grounded).

For the High beams, the WHT wire should be grounded.

Do not ground the RED and WHT wires from the Low and High Beams simultaneously.

LT GRN is for the exterior lights only, (side markers, and taillights) and powered by the TNS relay. This is not needed for function of the headlights as it is on its own circuit.

Hope this helps.

https://cimg1.ibsrv.net/gimg/www.mia...423f2e76fc.jpg

Thank Brian Z.

What you wrote is exactly how I have it wired right now.

On Low Beam...The following 3 wires all connect to ground...RED, RED/YEL, LT GRN
On High Beam...The following 3 wires all connect to ground...WHT, RED/YEL, LT GRN
(NOTE: I wired the car so that I don't have an option to turn on just the exterior lights, the exterior lights will come on anytime the headlights come on...Thus why I have the LT GRN wire attached.)

How this switch works. When you push the toggle down, it connects the top post & the middle post together inside the switch..(i.e Low Beam) When you put the toggle in the middle, there is no connection between any posts (i.e. OFF) When you push the toggle up, it connects the bottom post & the middle post together inside the switch...(i.e. High Beam)

Here is a pic on how I wired my switch...
https://cimg2.ibsrv.net/gimg/www.mia...fe7753271b.jpg

I appreciate that you are confirming that I wired everything correctly. I still don't understand why the Low Beam Ground wire (RED) is a thicker wire than the High Beam Ground wire (WHT). Also don't understand why the light output is the same both on Low & High beam, but maybe I just can't tell the difference.

Which just gave me an idea (don't know why it took till now to think of this) I have a stock Miata sitting right beside this one, without a bastardized wiring harness. I'll test the high & low beam light output from it and see if it looks the same to me or different. Maybe this is just a case of crapy lights/crapy eyes & much ado about nothing.

I'll report back with my light test findings.

Can you show a pic on a blank background?

I'm not sure what you mean. What picture do you want to see and how?

Quick update...

My other Miata you can definitely tell the difference between high & low beam. Still no difference with this car, light output looks the same in both cases.

At this point, unless someone has an idea, I'm just gonna send it. I do have lights & they will be very rarely used anyway.

Definitely appreciate the help! Kitty Cats for all.