Is there a inline resistor that will only allow power to flow one direction. If so whats it called where do I get it?
It's called a diode. It only allows voltage to flow in ONE direction. They come in diff. amp ratings. The band around the end points to power out.
What do you need it for? There are all kinds of ratings and voltages. You might try Radio Shack, for starters.
Just to be clear, a diode is a current device not a voltage device and it is not a resistor. It is correct that it will allow current to flow in one direction and not the other but, will not drop any voltage (maybe drop 0.7 to 1.5 depending on the current load). What's your application for this device?
I converted the hide away headlight operation in the Riv from Vac to electric using parts from a 67 assembly. To trigger the relay I first used power from the low beam headlight. It worked great until I put on the high beams. Then the lights would shut while driving at night. Next I ran power from the main feed @ the dimmer switch. That works great on high and low beam. Also installed a "Test Switch" under the hood near the latch. It never fails that people at shows want to see the lights work. Issue I have now is that the lights come on when the test switch is pushed. Want to limit the current from going back to the dimmer switch.
Briz, Without seeing exactly how you are wired not sure but see if this might work. Install another relay with a normally closed contact and run the power wire from the dimmer switch powering the headlamps through the normally closed contact. Wire your test switch to energize this relay. When it energizes, the NC contact will open preventing lights from coming on.
yes, I had to do this for towing my blazer behind the motorhome. get them at any tow hitch shop. for them this is common practice and the right person will explain the proper way to install. easy.
I don't claim to know a lot about your headlight door conversion but, I think you can accomplish what you need with a diode rated for 5 amps forward current. (as long as it's not also the wire that carries the current for the headlights). As long as your doors don't draw more than 3 or 4 amps, this one should work. It will only drop about .66 volts when your doors are open. You can probably also get a diode at Radio Shack. https://www.westfloridacomponents.c...+Amp+80V+General+Purpose+Rectifier+Diode.html
Think this is exactly what I need. The relay that powers the electric motor is directly wired to the battery through a 15A fuse. The wire from the dimmer only activates the relay. The lights are powered through all the factory wiring.
OK, now I don't think you need a diode. How do you have the test switch wired? Is it a push button or a toggle switch? Also, does your relay have three contacts on it? Like this?
I'm thinking this circuit should work for you. You probably have the relay already wired this way so, all you have to do is put the test switch on the normally closed contact of the relay (if there is one). Your 15 amp fuse will go from your 12 volt source to the relay and test switch before the motor. No need for a diode as the dimmer line is isolated from everything else already.
the headlight motor has 2 power leads. one to open and one to close. There is a cam that hits a micro switch to stop travel in each direction. Put power to the relay and it closes one power lead and opens the other. Remove power to the relay and it energizes the other lead to close the doors.
Got it. I'll work in this and get back. Is the relay a factory part or a special one just for this project?
Over the parts store counter. Same relay that I use on the Regal for the NOS and 2 step. When the button is pressed the trans brake and 2 step get power but cuts power to trigger the NOS system. Let go of the button and the 2 step rev limiter / trans brake lets go and the NOS fires as long as the WOT switch is closed.
I think I see how you're wired now so this one should do it. I'd use two diodes, they're cheap. That way, you isolate each 12v source (dimmer & test switch) from the other. You mentioned that you're using a 15 amp fuse. If that fuse is just feeding the relay coil and the motor windings and nothing else, I think I'd reduce it to just double what the motors are drawing, whatever that is. By the way, if you haven't used diodes before, the cathode of each diode are tied together and attach to the relay coil and the cathode is the end with the stripe on it.
This is correct. ^^. I ordered the diode you listed a few post above. Think your right on track putting it in the trigger line to stop the current from going back to the dimmer and bringing on the head lights.
I think you definitely need the second diode in the test switch line. If there were ever a case where the lights were on and the test switch activated, you would be supplying 12 volts from both the dimmer switch and the battery to the motor and that's not advisable. The second diode would prevent that possibility. :TU:
I cant foresee where that will ever happen. Only use the switch at shows to demonstrate the function of the hideaway headlights. In the past with the Vac operation I would have to start the car many times throughout the day so spectators could see it work. Now all I do is push a button. Next will be a free standing coin box with a changer in it. drop a quarter and it will trigger a 5 sec feed of power, open and close. Why not make a buck or 2?
