Triumphrat

bonniesaltrat · 07-12-2007

I had followed the thread(s) about use of the Superbrite LEDs in the instrument panel to give brighter instrument lights. (The Thread) (The Other Thread) But the story never seemed to get finished. Either that, or I'm just an idiot.

Following Programr's instructions, I am preparing to install a Signalminder to convert my turn indicators to running lights. I intend to add diodes to the wiring for the right and left turn signals to avoid the cross talk issue discussed by Programr in his thread on the Signalminder install. I am also installing one of D9's lay-flat gauge brackets, which just arrived and looks fantastic. As Ridge suggested in his review of D9's brackets--which was very nicely done, BTW--this would be a good time to swap out the stock indicator bulbs for LEDs. I already purchased the 74 wedge base LED bulbs that Ridge and others talk about.

But from the threads on the LED bulbs, it wasn't clear to me whether the 74 wedge bulbs would work. I don't know jack about electronics, so this may be an utterly stupid question, but will the 74 wedge-base LED bulbs work if I am adding diodes to the turn signal wiring anyway for the Signalminder? Jenkspj commented that "the turn signal is a problem for LEDs because the polarity alternates with left and right indicator. For a filament bulb this is not an issue, but 99% of LEDs are sensitive to polarity." Does the addition of the diodes in the turn signal wiring solve this polarity problem, thus enabling me to use the 74 wedge-base LEDs?

Your thoughts would be greatly appreciated.

[ This message was edited by: bonniesaltrat on 2007-07-12 12:20 ]

Baltobonneville · 07-12-2007

I've been looking at this for a while. I was going to do it when I installed the D9 bracket, but decided that I didn't want to commence a new sub-project at that time.

Per private communication from Ridge and Dazco, they don't believe that the diodes are needed if you use the 6-LED non-polarized lamp.

However, I'm thinking that if you do the running lights modification, you might need the diodes anyway. I'm not sure why I think this, because I haven't looked at it in a while.

If I were doing it, I'd try the LED first without the diodes and without the running lights. See if that works, then do the running lights mod and see if that works without the diodes, then finally add the diodes if needed.

Good luck getting those LED bulbs in the holders. It's a PIA even getting the old bulbs out. There is no socket in there, just two clips that must be seated in the bottom of the rubber holder to stay in place and make contact with the bulb contacts.

I've been occasionally playing with my old speedo-only wiring harness, and there is no obvious or intuitive way to get the new 6-LED bulb in there. The base will have to be filed down to fit, then the whole somewhat-oversized thing will have to be "persuaded" to go down into the holder, and you can only hope that proper contact will be made.

One forum member hard-wired the LED bulbs. If I were doing that, I'd solder the connection and use some heat-shrink tubing. This would give you the option to mount them at any height within the holder, assuming that they'll stay put.

One other thing that I've learned from reading these posts is that odd things happen when you start mixing filament lamps with LEDs, and thermal (OEM) flashers with electronic flashers. I installed the auto-canceling electronic flasher, and up to now have not had the motivation to try to make the LED idiot lights fit and work properly, although I don't like that I can't see the neutral and turn signal lights on a sunny day.

If you do it, please post pictures and explain what you did, what worked, and what didn't.

[edit] PS The LED bulbs should work with the diodes. If they're polarized, they might only work one way, i.e. one specific terminal to the diode, but that's easy to figure out. If they're non-polarized, there should be no problem at all.

[ This message was edited by: Baltobonneville on 2007-07-12 21:19 ]

bonniesaltrat · 07-13-2007

Thanks for your thoughts, Marty. I already have the 74 wedge type LED bulbs, so I want to try to make those work. And I don't want the added headache of doing the surgery on the 6-LED bulbs that others have tried.

I guess my confusion arises because I don't really understand what "polarity" means. As I understand Programr's instructions for installing the Signalminder, diodes must be installed in both the right and left blinker circuit. This is because we have only one dash indicator light for both the right and left signals. If the left blinker is activated, there is a small amount of current which bleeds off through the right side, which acts as the ground. This apparently causes the Signalminder to malfunction when you use it to create running lights. The fix is to add a diode to the wiring for the right and left blinker circuits, thereby preventing current from bleeding down the other side as the ground. You then add a separate ground wire.

I understand that the problem with using a single LED bulb in the instrument panel is that the single LEDs are polarized and only work in one direction. Specifically, in one of the LED instrument threads, FlyingMerkel commented:

"I did some banging around with my multimeter on the bike and on the internet and here is what I have discovered so far. The two wires that attach to the turnsignal indicator bulb reverse polarity between right and left turns, no big deal for an incandesant bulb, but the wedge base type 74 LED's are polarized and will only work in one direction, that is only flash during right or left turns depending on how it is installed. According to Greg at superbrightleds, the type 74 bulb is too small to include the non-polarized circuitry." He then proceeded to install one of the 6 LED bulbs, which are "nonpolarized."

So back to my confusion over what "polarity" is. If I am installing diodes in each turn signal circuit so that current flows only one way in each circuit, does this solve the "polarity" problem with the single bulb LEDs?

Again, if the answer to this question is painfully obvious, please excuse my ignorance.

Fast_Fashion · 07-13-2007

I put Red LED's in my gauges and didn't do a bit of wiring. Never had a problem as the LED's were the correct voltage.

edit: I used the 74's

[ This message was edited by: Fast_Fashion on 2007-07-13 01:43 ]

Baltobonneville · 07-13-2007

Getting back to the polarity issue, here's the best summary I can muster right now:

The diode arrangement and bit of rewiring is to ensure that the polarity going into the idiot light LED is always the same, regardless of which side is blinking.

Think of it as meaning that the direct-current electricity can only flow in one direction because the LED doesn't work when the current flows in the other direction.

In the stock setup, it flows in either direction, depending upon which side is blinking.

Since a non-polarized LED can work either way, the diodes should not be necessary for the non-polarized type (although they might still be necessary to make the running lights work, which is a separate issue relating to the wiring that has to be added).

Once you've set up the wiring such that the current only "goes in one direction" to the idiot light regardless of which side is blinking, polarity means that you must connect the correct terminal of the LED to the correct terminal in the light bulb socket.

In real life, this means that if it doesn't work, you pull the LED, turn it 180 degrees, and re-seat it.

All of this is only a problem for the turn signal circuit. The other idiot lights can simply be replaced with LEDs, although there are some reports that they will glow very faintly due to current leakage that is a non-issue with filament bulbs. This is because they require so little current to light up.

I'm curious as to how bright you find the single LED compared to the stock bulb. Looking at my 6-LED version, I would think that a 4-LED arrangement would be just the right size, but the vendor doesn't seem to have such a size.

bonniesaltrat · 07-13-2007

Thanks Marty. That helped a lot. I've got other work on the Bonnie slated for this weekend, but I'm hoping to do the Signalminder/lay-flat bracket/LED replacement/headlight modulator work next weekend. I'll repost and let you know how it goes and how the LEDs work. The stock bulbs are so dim, the LED's gotta be brighter. I think a forum member in one of the earlier threads indicated that the 74s are brighter.

Baltobonneville · 07-14-2007

In re-reading my last post, I noticed that I did not make clear, in paragraph 8, when I said ...

"there are some reports that they will glow very faintly due to current leakage that is a non-issue with filament bulbs"

... I was referring to "glow very faintly" when they are "off".

When they are on, they're on at the normal brightness.