iamwieb

Hooked up a couple 100watt lights to my truck using just the lead for the reverse lights to power them, grounded to bumper. When messing with them tonight I heard a loud pop and now reverse lights wont work, ( just got a new switch) and not a single gauge on my cluster works. What do you think happened? Where do I start? 95 3.0 standard pickup.

Gevo

Ouch. Have you checked the fuses? Thats exactly what a fuse is for.

RAD4Runner

100 watts! Goodness! That's more than a headlight! You should not hook up just anything without first checking how much power/current the circuit can carry.

10-Amp "Gauge" fuse, connected to integration relay.

That means approx 120 watts is maximum for that circuit to power gauges, back-up lights, etc. add 100-watt bulb and BOOM!

If you want brighter back-up lights, you need a relay circuit OR LED lights-more light for low power.

wyoming9

iTrader: (1)

I really want to know what the loud Kaboom was ??

The arc right where you were grounding might make a snapping noise but never a popping sound.

When a fuse opens unless you have your head right at the fuse block I doubt you would hear it.

Now since the back up lights were on I wonder did the bulbs explode??

adding 2 100 watt bulbs to the circuit caused a massive current draw

iamwieb

Thanks guys, it was dark and I had some beers in me so I didn't wanna fumble dome fuses, already changed it this morning and gauges are back on. Love a simple fix, I do live in Texas so it could have been a gun or something, it just kinda happened when I was messing around with the lights.

Reverse lights still don't work but a switch is only 20$ so I'll replace that.

I got these lights off CL for cheap and I'm an ok electrician but that comes with a few blown fuses along the way.

I'm wondering how I could get these hooked up?
Where would resistors go along the power path, should I just go to the battery and a toggle? I'd like them to work seemlessly with the reverse lights and eventually with a toggle for the trail.

Thanks for the help. Btw I hooked both lights to one lead coming off the reverse light power wire, had to try, sometimes I just want stuff to be easier.

iamwieb

Thanks, bulbs look ok. Loud noise was like a gunshot. I live in Texas so maybe it was that, or my neighbors screen door slamming or something.

iamwieb

What is a relay circuit?

iamwieb

Guessing this is what I want to do.

JasonYota

iTrader: (1)

Your an "ok electrician" but don't know what a relay is?

iamwieb

I know what one is but never installed one.

As far as my skills go, you're right, I'm a lousy electrician. Wish me luck.

Gevo

Well, you need a relay as you've figured by now. You don't need the one you showed a double throw, just a SPSD. It's just like a switch, except 'flipping' a relay requires a little power. First of all, make sure you get a relay rated for 100 watts at 12 volts. Most relays will have the rating in AMPS. Use a simple online calculator to convert the amps to watts at 12 volts. Once you have that, buy the relay and it's fairly easy to set it up. I imagine the current draw of the relay circuit is not very much and can be wired right into your back-up light circuit. Oh, make sure you get a NORMALLY OPEN relay.

turkeykiller365

I prefer the "quick and dirty" approach to hooking up lights.
step 1) run wire from battery to switch, then from switch to lights
step 2) ground lights.
step 3) replace switch every two weeks.
step 4) buy an industrial switch that can handle everything.
step 5) melting and fires.
step 6) "yes, officer, im aware that my right turn signal is the only light on my truck, and that it only illuminates when I hit the brakes."

turkeykiller365

no but seriously I never understood relays until I took an electrical engineering course (don't worry, that's not my major). Theyre awesome. Try to understand how they work before you go hooking them up. Google some stuff.

Gevo

Then you must have been working on your BS in ME or CE .. maybe MSE... ?

"Replace switch every two weeks".. lol.

scope103

Resistors? There shouldn't be any resistors in a lighting hookup

Power (watts) = volts x amps. If you need an online calculator for that ...

100 watt 12v bulbs, therefore, draw 8.3 amps. When they turn on, there's a big in-rush current (when the filament is cold the resistance is lower), so you'd need a minimum 10amp relay. Which, fortunately, is a run-of-the-mill relay. (PS: it has to be rated for at least 10amp DC; DC is harder on relays than AC.)

For the lead from the battery to the relay to the lights, 12ga will (just barely) be enough, but you'll get a 6% voltage drop. Bigger wire would be a little better, but 12 is pretty hard to pull already. I would recommend running a separate ground wire back to the battery, rather than relying on the frame; the factory lights have a wired ground. (And don't try to "ground" anything to the bed; it's mounted on insulators!)

Last, if your battery is not brand new, don't leave those lights on for very long without the engine running. 8.3 amps is a big load.

edit: Oh, wait, you're talking about "a couple" of 100watt bulbs. Make that a 20amp relay, and 10ga wire minimum.

RAD4Runner

Listen to Geveo and Scope and ^^, except for turkeykiller365' joke, of course- LOL!

Yes.

Disconnect those bulbs, troubleshoot back-up lights first.

Got a Digitam Multi-meter? Next to our senses - sight, touch, smell, hearing, and common- the DMM is the best tool for troubleshooting our trucks. Do not even do anything electrical until you have one.

Wait for a diagram. It's simple.

Gevo

Power (watts) = volts x amps. If you need an online calculator for that ...


LOL!

Gevo

You know .. we get so hung up trying to help a guy solve his problems, we forget to stop and say.. wtf you need two 100 watt rear facing lights for ONLY when you're backing up?

iamwieb

Wouldn't say I need them, I just had them and didn't want to mount these huge lights up front (they're huge in size) ( pro comp explorers) and wanted to see a bit better to back up, maybe light up a field when backed up.

Dunno, just trying to hook up something that came on from a stock switch.

Appreciate all the help and I've learned a lot. Thanx

Sturmcrow

I would add that you can get 40 amp bosch-style relays with harnesses on Amazon for dirt cheap. I usually buy the 5 pack, since I end up using them a lot for various on-car and off-car projects. For this project, you would only need one. The leads on the harness are not very big, but you can pull the sockets out, open up the clamps, and put in bigger wire if you desire.



For what its worth, I have these on my headlight upgrade wiring harness. They've been there for over a year with no problems. That said, I do carry a couple of spares, just in case. I also used 4 of them to install a bluetooth handsfree in my wife's car, with no problems.

I should add that I am pretty impressed that you did not lash out at the forum folks having a little fun with you. Most folks get up in a snit, which really does not accomplish much at all.