bobholthaus

I need to install a diode between my dome light circuit and the LEDs on my OTRATTW switches. Right now, when I turn the key one, the wording on my switches illuminates. Since some of my switches are constant current (meaning I can turn them on without the keys in the ignition), I want to have the wording also light up when I open the door (tripping the dome light circuit). So, I need one diode as mentioned above, and I guess I also need one between my switched circuit and the same LEDs, so the power doesn't back flow that way either. Can someone help me with where and what to buy? This is my first diode purchase/install ever.

I'm also going to use one on my Rigid SRM2 rear diffused lights (in red) that I'm wiring for both constant on (to be used in inclement weather) and also with a flasher unit as emergency lights. Two different sets of wiring will hit the lights themselves because of this, so I need a diode on each set there too. I'm assuming diodes are like wiring gauge and come in different "capacities"? "Diodes 101" is really what I'm asking for. Thanks!

jeepnutt

Radio shack has 1amp ,3amp and 6amp diodes or you can find them online. Try this site for info on diodes
Blocking Diodes, Isolating Door Triggers and Sensors
and
Diode tutorial and AC to DC conversion | Electronics tutorial videos
thank rednroll for finding this video site, it gives you info. on how they work.
The lights in the back should be wired up to a relay. Then you use two diodes to isolate the two inputs you have going to the relay.

bobholthaus

Thanks man, I will check those links. On my rear lights, there is a flasher device that has to go right before the lights, so a single output relay won't work, as I want to run them "on" or as a flasher, so I need two separate lines coming from my three-way switch, one going straight to the lights (on mode) and one going to the flasher unit then the lights (flasher mode). So, to inputs to the lights at the end of the run. If I really wanted to do it correctly, with "clean power" going to the lights, I'd run 2 relays. But for some led SRM2 lights, I'm not going to hassle with the relays; I'll run 14 or 16 gauge wire through the switch and that should deliver plenty of juice to the lights (obviously ill check wattage for the proper gauge wire and fuse size).

The last time I went to radio shack to ask about diodes, they had no idea how to explain the different part numbers they sell. Let me figure out my amp load for the lights and I might ask you to help me with exact part numbers. Thanks again.

JK-Ford

Adding a seperate relay for each individual control source builds in a layer of protection that you can't get with diodes.

bobholthaus

Ok, I bought a 3A 50v diode at Radio Shack (I'll add part number later - I didn't realize that those 1N400X numbers were standard across the industry). I did a temporary hookup of my SRM2 lights (one light per diode) and although the diode got warm, it did not get hot. After watching that video above, I learned that the heat of the diode causes the approximate .7v drop in output across the diode. So thankfully the Rigid's can handle a range of voltages. I did not try the diode with the flasher yet, but the box for the flasher says 3A, so I'm assuming they'll be fine together since they're both 3A. I'll update this when I'm finished.

Btw, the 3A diodes come in 50v, like 300v and 600v, and in 1A and I think 3A. Why the different voltages?

Thanks.