Sold on LEDs

[racer47201]

Hello all!  I sent an email to Dapper Lighting about filling our needs for LED dash lights in a kit form with a pulse width dimmer included.  I haven't seen their reply yet.  Maybe others could request them from Ben and Jonathan at Dapper Lighting to show our interest in them.  Email: info@dapperlighting.com

[TomoHawk]

They either won't reply or  reply negatively, like most other parts suppliers.  That's because there isn't a PWM dimmer for the S30 listed in their catalog, or any catalog.  Most people don't understand that  you will have to re-engineer things  to fit the S30, so they just say "it's not cost-effective" and recommend that you buy new parts from your vehicle's dealer.

I think MSA has those "small bulbs" in their catalog, but if those small bulbs burn out. I would just replace it with an LED.  You could probably fit a  discrete LED into the socket somehow and solder it directly to the original wires. 

I think the best thing we  can do is to have those who install LED bulbs to keep  detailed records of the bulbs used, then agree on a common spec for a "kit," and then you might be able to get a supplier to provide something, possibly even a PWM unit that you would have to modify yourself to fit your car.

Edited April 8, 2016 by TomoHawk

[TomoHawk]

Has anyone besides Cap'n O installed a PWM to control the illumination? 

The rheostat on the Zed is on the ground leg of the bulbs, but most PWMs typically control  the battery + side of the power, so it would be good you have a PWM that will switch the grounds for the LEDs.  Maybe auto manufacturers have taken that into account on newer cars, so we could just use one pf those, instead of rewiring the entire illumination system?

[Captain Obvious]

All of the automotive PWM dimmers that I've messed with control the lights the same way the original rheostat does... By varying the amount of bulb current to ground.

Goes like this: When you turn the lights on. one side of the bulb is connected directly to +12. The other side of the bulb is pulled to ground through the rheostat.
The PWM dimmer does the same thing except it pulls to ground with an intermittent connection through a switch (transistor).

Of course, I haven't dissected a dimmer from every car ever, but the "low side switching" scheme is easier to accomplish in electronics, and I suspect most of them work that way.

Also note that the early Z's operated differently and had the rheostat on the high side of the bulbs. The PWM dimmers I've messed with would not work on those early cars without additional changes to the cars wiring.

[TomoHawk]

In that case you can use a  DC motor PWM controller, which switches the +12V side.

 I suppose the ones on trucks are the same as what cars have, so there is not really a "Heavy-Duty" PWM dimmer?

 

Edited April 9, 2016 by TomoHawk

[TomoHawk]

Does anyone want a lighting switch  from a Ford Econoline van?  It has switches to control parking lamps and headlamps, plus a rheostat all-in-one. It will double as an anchor too.

Edited April 9, 2016 by TomoHawk

[Captain Obvious]

Calling it "heavy duty" doesn't tell you whether it's a high side or a low side driver. Without seeing it, I suspect that's more about the relative current handling capacity of the device. The small ones I've been messing with are designed for a total current from a couple dash bulbs. If you were to try to dim a three 10W incandescents, you could burn up the insides of the module because it might not be able to deal with that much current.

Low side drivers have always been easier to produce because of the fixed reference point (ground) and inherent transistor technology. High side is of course possible, but usually more complicated and more expensive.

[TomoHawk]

So besides going to the JY, where can you get a commercially-made PWM that would work for the Zed?  You can get PWMs  very cheaply on eBay,  but  there is not enough details to tell if it'll work on a Zed.They are all for DC motors.

[TomoHawk]

Here is a new idea to improve the illumination   and viewing of the gauges at night:

What if you made a plate of thin, clear plastic using the metal one as a template, and put the gauge overlay on that? In theory, the light from behind should show through the face in addition to what reflects from the edges, and if you use a reverse color scheme (white marks & numbers on dark background) it should be easy to read.

[Captain Obvious]

Many manufactures did that printing on a clear plastic scheme. Then they backlight the gauge and the light passes through the silk screened plastic. Trying to redesign the Z to use such a scheme, however, would be darn near impossible.

As for where to get PWM controllers, you would need to ask enough questions or read enough documentation to determine if they are high side or low side controllers. Not easy to do.

[TomoHawk]

I don't think it's impossible;  it just requires some time, effort, and resourcefulness:

I have some clear translucent label material that I use for making decals for little things, and I could easily print a gauge overlay on it, and make a faceplate from some scrap plastic.   Cut a hole in a cardboard box to for the plastic face to fit into and wire some LEDs, or even a turn or brake lamp bulb, to backlight the imitation gauge face.  Then if the experiment looks like it has promise, you refine things to retrofit into gauges, hopefully.

[TomoHawk]

I set up the test rig for the Toyota PWM dimmer and it worked.  I tried it with combinations of incandescent and LED bulbs and I got the best control (0-100% brightness) using the combination of bulbs, as we discovered works best with the stock rheostat. 

The module didn't get warm or let the magic smoke out, so I can only try in in the car.  I think you will need to run 1 witre from a 12V source (the headlamp switch) You only have to figure out what mix of incandescent & LED bulbs  will illuminate things correctly.

The test rig diagram:

This photo has a mixture of bulbs, with the control set to full-on.  The dimmer is from a 1990s Toyota Corolla or Celica.

Edited April 10, 2016 by TomoHawk