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Wiring relays...

Smokinthehippies

Smokinthehippies

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I am wiring up my wife's led bar and having issues.

Based on the wiring instructions from the relay, I'm not sure if I need to run both of the middle connections to the positive or what?
Currently I have only the outermost tab going to the light positive and the center tab is empty.
Basically the problem I'm getting is when i hit the switch to engage it's only send 5.5v to the light bar. What the hell am I doing wrong?
Help please so I can illuminate the night

image.jpg
 
Think of 87 and 87a as a double pole switch. On is on while the other one is off.
 
See that's what I did. I have my fused battery coming into 30, and my power signal to light going from 87.

So why the hell is it only showing 5.5v at 87?
Unless I blew the relay somehow.
 
You don't mean 85 or 86? That is coil in the relay. if you are sending power though 86, 85 should read lower.

wiring a relay simple..png
 
Smokinthehippies said:
See that's what I did. I have my fused battery coming into 30, and my power signal to light going from 87.

So why the hell is it only showing 5.5v at 87?
Unless I blew the relay somehow.
Click to expand...
The connection between 30 and 87 is mechanical. When the relay is off, the connection is open. There is physical air between the two. If you getting a reading, it may be fused together.
 
JDNobodi said:
The connection between 30 and 87 is mechanical. When the relay is off, the connection is open. There is physical air between the two. If you getting a reading, it may be fused together.
Click to expand...

when the switch is off, 87 shows nothing.
with the switch on, 87 shows 5.5, not the 12ish I was hoping for.

otherwise my wiring setup matches what you have shown.
 
How good is your connection? Are you measuring your voltage to the terminal that you crimped on or the spade that comes out of the relay.
 
JDNobodi said:
How good is your connection? Are you measuring your voltage to the terminal that you crimped on or the spade that comes out of the relay.
Click to expand...

That is measuring right at the relay point. Using the relay ground I show 12 at the ground and battery
12 at the ground and switch
And 5 at the ground and feed
 
Probably easiest to just plug a new relay into it and see if it does the same thing. If you still get 5V, something other than the relay is the problem.
 
bp71k5 said:
Probably easiest to just plug a new relay into it and see if it does the same thing. If you still get 5V, something other than the relay is the problem.
Click to expand...

That's my next step when my wife has a day off again so we are both home at the same time
 
Finally got back in this.

Grabbed a spare relay just to make sure. And this one I can hear clicking on and off so I know it's functioning.
But still no joy.

Basically there is a weather right plug about 6" from the light. On the feed side with everything on in getting 10.5v with truck off.
But as soon as I plug in the light bar side of the connector I only show 5.5v and nothing happens.

Now to confirm my work I also used a battery charger to put 12v to the light bar half and it lit up perfectly.

So wtf?!?
Help me out if you can.
I know what I'm leaning towards but I had to call it a night as the Mosquitos were coming in thick.
 
Do you have the 5 at the end of wire or the tab on relay. Sounds as if it may be a resistance problem.
 
Jester1 said:
Do you have the 5 at the end of wire or the tab on relay. Sounds as if it may be a resistance problem.
Click to expand...

Nope. All the terminals at the relay show 12. And the full run of the wire shows the same as long as the light isn't connected.
 
Should probably charge your battery if it's inly giving 10V. It may be that the lights take up more current than the battery can give and so they just suck the voltage down to 5v. Maybe just put the charger on the battery when your testing it to make sure.
 
Ok power through is good what size wire are you running. Or may be ground location at light. Or the led driver within light?
 
bp71k5 said:
Should probably charge your battery if it's inly giving 10V. It may be that the lights take up more current than the battery can give and so they just suck the voltage down to 5v. Maybe just put the charger on the battery when your testing it to make sure.
Click to expand...

Yeah tomoro I'm gonna try it with the truck on / charger hooked up to make sure it's not a battery issue.

Jester1 said:
Ok power through is good what size wire are you running. Or may be ground location at light. Or the led driver within light?
Click to expand...

I know the light drivers work cuz it shines great when I hook it straight up to the battery charger.
I'm running 12ga on both where the light factory wire was a 14ga so I should be good.

I'm really leaning on it being the ground. Or I should say I'm praying it's the ground lol. Thinking on it earlier. When I tested that ground I just used a circuit light not the voltmeter. So I'm betting it's the issue.

Either way I'm gonna run new jumpers straight from battery to light tomoro and then work my way down from there to figure this bitch out.
 
Got this solved.

Battery in the Tahoe is on the way out. That was the problem. As soon as I started the truck everything worked as specified.
Granted it's too brite out to see if it really lights up like it should. But I'll try and check that when she is off work tonight.

Thanks everybody for the help. I haven't done too many relay'd setups before so its always helpful to have experienced before kinda double check the work.
 
Bringing this back. Got beaten again.

So it got dark last night hit the switch and ....
The LEDs are firing but they're not lighting off. It's just enough glow to see that they're working and that's it.

When I claimed victory it was brite daylight out and I could see the led changing from off to on but just barely so that must've been what I was seeing. Now im at a loss.

Gonna try to play with it tomorrow after work when she is off but I'm about out of idears
 
When the lights are on, truck running, check the voltage at the lights if you can get access to an exposed wire. Make sure you don't have a loose wire or fusable link.
 
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