I think I have too many lights now...HELP

[MrBash]

OK here's what's going on. I have a 2002 TJ 4.0

I have four 100watt Lights on my light bar connected to a 30 amp relay, a 30 amp fuse and a heavy duty rocker switch.

I have two 55 wat rock lights connected to the factory fog light wires.

I have four 55watt rock lights connected to a 30 amp relay, a 15 amp fuse and a heavy duty rocker switch

Plus my two 55watt factory headlights.

Total wattage is 840 when I turn all the lights on.

I'm currently running a factory alternator with a Yellowtop battery.

I tested all the lights yesterday while the engine was on idle. Just a few minutes after, the battery voltage meter wen to approx 10 volts. I left it like that for about 10 minutes and it was still around 10 volts. When I rev'd the engine, the battery voltage meter went back up to 14 volts.

I drove the Jeep around the parking lot with all the lights on for 10 minutes and the battery voltage meter stayed at 14 volts (which is normal).

I don't want to have something burn up in the middle of the trail in the middle of the night so my question is, will my alternator coupled with the Yellow tyop battery carry this much wattage or will something fail? Should I upgrade my alternator or install a second yellow top battery? what do you guys think?

[womb raider 940]

umm even offroad I dont think you will need that many lights. I have 2 130's up front. and 4 hellas on the light bar. Then I have the stock headlights and fog lights. Plenty for me.

You can either go with a dual battery setup or bigger alternator.

[Shadly1]

It's great that you're using relays but it is very taxing on your alternator when everything is lit up. Even though you're staying at 14V, you're increasing the duty cycle of the alternator. If you have a high quality one in place, you could go years before you have a problem. When you get around to it, replace that alternator with a high output one and replace all your crimped terminal ends with soldered lugs. Replace your ground straps too. A second battery is a good idea for the trail but not a requirement. If you blow an alternator on the trail, a second battery will get you twice as far and that may be enough to get you back to civilization. I had an alternator fail in Calico and I was able to ride my battery all the way off the trail and into the Autozone in Barstow.

[Shadly1]

umm even offroad I dont think you will need that many lights. I have 2 130's up front. and 4 hellas on the light bar. Then I have the stock headlights and fog lights. Plenty for me.

You can either go with a dual battery setup or bigger alternator.

You're stuff is BLINDING!!! I'm still seeing halos around everything. I think you may be a few steps past daylight

[MrBash]

umm even offroad I dont think you will need that many lights. I have 2 130's up front. and 4 hellas on the light bar. Then I have the stock headlights and fog lights. Plenty for me.

You can either go with a dual battery setup or bigger alternator.

It's not about needs when it comes to my lights, it's about wants. I want everything lit up around me, under me, over me, here, there, everywhere

I like it! I think when I'm wheeling Calico this Sunday night, I will alternate between the lights I need.

[MrBash]

It's great that you're using relays but it is very taxing on your alternator when everything is lit up. Even though you're staying at 14V, you're increasing the duty cycle of the alternator. If you have a high quality one in place, you could go years before you have a problem. When you get around to it, replace that alternator with a high output one and replace all your crimped terminal ends with soldered lugs. Replace your ground straps too. A second battery is a good idea for the trail but not a requirement. If you blow an alternator on the trail, a second battery will get you twice as far and that may be enough to get you back to civilization. I had an alternator fail in Calico and I was able to ride my battery all the way off the trail and into the Autozone in Barstow.

Thanks for the info. I just won't light everything up at the same time until I get a stronger alternator. Another memeber suggestes I use LED's for my rock lights so I won't drain as much power. Once these lights break (some day) I'll swithc them to LED's and upgrade my alternator when I get the mula. Thanks for info and all the help.

[seapahn]

The battery is fairly irrelevant here as long as it is in good condition ... you can have 10 batteries and still that won't affect the load on the alternator which will try to keep all the loads running AND keep charging the battery(ies). A bad battery of course will put additional load on the alternator. So if you want all those lights on and not have the voltage drop, you'll definitely need a bigger alternator. However, keep in mind that at idle, most alternators will not be able to keep up with that kind of load and you may still see voltages drop. But at least the larger alternators (which usually have a fan too) won't burn up as easily.

FYI, the 30amp relay and fuse might be straining with the 4 x 100W lights. If the wiring isn't hard, I'd recommend splitting those lights into 2 separate circuits. 100W at 12V is over 8amps of current. Four of them would mean over 30 amps for sure (but at 12V). At 10V, 4 x 100W would be pulling 40amps!

[NAILER341]

get rid of some of the lights. no one wants you behind them with all of those lights on.

[MrBash]

get rid of some of the lights. no one wants you behind them with all of those lights on.

I'll make sure I'll be right behind ya on the next run

[MrBash]

The battery is fairly irrelevant here as long as it is in good condition ... you can have 10 batteries and still that won't affect the load on the alternator which will try to keep all the loads running AND keep charging the battery(ies). A bad battery of course will put additional load on the alternator. So if you want all those lights on and not have the voltage drop, you'll definitely need a bigger alternator. However, keep in mind that at idle, most alternators will not be able to keep up with that kind of load and you may still see voltages drop. But at least the larger alternators (which usually have a fan too) won't burn up as easily.

FYI, the 30amp relay and fuse might be straining with the 4 x 100W lights. If the wiring isn't hard, I'd recommend splitting those lights into 2 separate circuits. 100W at 12V is over 8amps of current. Four of them would mean over 30 amps for sure (but at 12V). At 10V, 4 x 100W would be pulling 40amps!

I see. Wiring is a bitch for the light bar so i'll just leave that one alone for now. I've been running the light bar with the 30 amp relay and the 30 amp fuse and haven't had a problem yet.

I have come to the conclusion that I can NOT run four 100W lights and eight 55 watt lights at the same time.

I can however run...

1) light bar, 2 rock lights and headlight = 620 watts
2) headlights and all six rock lights = 440 watts
3) light bar and four rock lights = 620 watts

Kind of confusing unless you can paint a picture of it in your mind. I'll just use the lights that I need in each particular situation. The best part, it's going to be a breeze to change tires, oil, broken exle and drive shafts, and replace steering arms in the dark

[Shadly1]

FYI, the 30amp relay and fuse might be straining with the 4 x 100W lights. If the wiring isn't hard, I'd recommend splitting those lights into 2 separate circuits. 100W at 12V is over 8amps of current. Four of them would mean over 30 amps for sure (but at 12V). At 10V, 4 x 100W would be pulling 40amps!

I was trying to figure that out but I forgot the formula. Do you know it or did you use a conversion calculator?

[NAILER341]

I'll make sure I'll be right behind ya on the next run

i have some rearward facing 100 watt lights for people like you

[MrBash]

i have some rearward facing 100 watt lights for people like you

hjahahahahahahha....damn I was luaghing my ass off when I read that. I like that one.

Wait a second.....that's it!!!!

Now I have to install 100 watt rearfacing lights. I'm going to need an alternator from a yacht for this one.

LOL!!!!!

[SteeevO]

FYI, the 30amp relay and fuse might be straining with the 4 x 100W lights. If the wiring isn't hard, I'd recommend splitting those lights into 2 separate circuits. 100W at 12V is over 8amps of current. Four of them would mean over 30 amps for sure (but at 12V). At 10V, 4 x 100W would be pulling 40amps!

I second that... I'd put atleast a 40 amp relay in there when you get a chance.

[Beatrice]

FYI, the 30amp relay and fuse might be straining with the 4 x 100W lights. If the wiring isn't hard, I'd recommend splitting those lights into 2 separate circuits. 100W at 12V is over 8amps of current. Four of them would mean over 30 amps for sure (but at 12V). At 10V, 4 x 100W would be pulling 40amps!

Voltage drop at 12 volts really starts around 4 feet, so wire size is more of the factor here, as is conection type and cleanliness. Plus a relay has around a 80 percent duty factor if it is going to be used continously (at 12 volts longer than 20 minutes.)
so I would sugest 2 parallel feeds of # 10 feeders on a 50 amp relay, protected each with a 30 amp inline fuse. I know this may sound like a lot of overkill when looking at the wiring harness that comes with the lights, but then those harnesses are designed to be used on trucks flying down a trail with plenty of air flow over the wiring, not crawling. Anyway, however you do it, just remember that a smoldering fire can burn down a 4x4 really quick. (ask Missy to show you pictures of here FJC after the Toyota Dealer burnt it to the ground) So overkill is best.
Another point you may want to consider is how many non DOT aproved lights are on the rig, In CA we are allowed 5. Now set the fog and driving lights on relays that will not let them turn on unless the low beams are on, make sure that the lenses say fog on 2 and driving on 2, and leagally you can run 9 lights. I know it may sound like a pain, but the ticket for the lights is a lot of hard earned fuel money wasted.
One more item I would add, with that many lights and switches, I would run a seperate switching circut that is activated by a relay that turns on when the ignition is turned on. You will thank me for that suggestion when you get out real quick and accidently hit one of those switches.