I have a light bar run through a relay on a 3 way switch. On/Off/on with high beams (off when highbeams are off) was the goal
Problem is I'm having an issue finding a high beam wire with sufficient voltage to trip the relay. I tried the wire off the back of the headlight switch. I forget its colour but it's a thicker wire. Maybe 14ga. It only gives me about 9v. Not enough to trip the relay.
Where else can I pull power from for this? are the highbeams on a factory relay? if so where is that?
My second question is similar. I have 2 small lights on my back bumper run through a 3 way. On/Off/on with reverse lights (off when not in reverse). Where can I pull power from for the reverse lights inside the cab? I don't want to tap in to a wire exposed to the elements nor do I want to run a long lead to the switch if I don't have to.
First, something's wrong with your claim that you can't find a wire with sufficient voltage to trip the relay. That just can't happen. The coil in your relay draws So Little that it would go unnoticed in almost any circuit (except maybe a dimmer at low). So something not right with either the wire you chose or how you're connecting it to that relay. For my lightbar (32" in-the-grille) I just went to one of the wires supplying the Hi-Beam at the bulb itself to trip my relay.
For my in-bumper LEDs, I use solder/glue-shrink for the connections back there and even have the relay there too. I wire the relay in a socket solder/shrink all the connections and then "dip" the entire assembly in Plasti Dip to seal out the world
sorry truck is the truck in my sig. early 03, ex 7.3 truck
As for the relay, it is the voltage. Relays have a min voltage cutoff for the magnet to have enough energy to close the circuit. Usually 8 or 9 volts. In my case, the 9v I'm getting isn't enough. I was surprised by this too, but this is the reality I'm dealt. The relay works with 12 volts, even 11 volts, but not 9
The issue isn't my connection, the issue is the voltage. I'm not here to debate this
Thanks for the wiring diagrams. I'm going to have a look at them now!
Yeah that's the magic question isn't it. Why that wire in the multifunction switch is only providing 9v I have no idea, but it is. It's only powered when the headlight high beams are energized to boot, which is why I tried to use it. I suppose it could be a wire relating to the dimmer. I hadn't thought of that before because it doesn't make sense. The wire is a larger gauge than all others (12 or 14ga I think) on the harness plug
My original guess was that the wire was too small of a gauge for the current flowing through it causing significant voltage drop
Are the high beams nice and bright or kinda dim? I would disconnect the head light/high beam connectors and see if your light bar will work . If so it may be your high beams themselves dropping the circuit voltage that much. I would be curious to see what the voltage is with those connectors disconnected.
I think I found what I'm looking for anyways. Well, for the reverse lamps anyways. After leaving the cjb the wire goes to the dtr sensor where the dtr sensor closes the circuit for the reverse lamps. The wire is routed back to the cjb to the trailer tow relay before heading back out to the reverse lamps. If I'm reading the diagram correctly anyways.
I believe I have located a spot on the diagram to check for the highbeams as well. Hopefully there is sufficient voltage to trip the relay
Good point. That or a poor ground wherever the head lights terminate. The headlights are kind of dim. Not as bright as they used to be. As for the voltage. There is zero voltage with the high beams off. Voltage only passes through the wire with high beams on.
disconnect the headlight connectors and see if the light bar works, need to make sure that you have 12v available at the headlights. If not then you have a wire/connection issue upstream, if they do then the high beams themselves could be to blame or poor grounds.
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