24 Volt light wireing brain fart

[big block 88]

Okay we have been mounting some additional lighting on the trucks front bumper and next ontop of the cab, but I ran into a brain fart it seems.

Attached is an image of how I hooked up the light they are mounted on a switch in the dash but I get NO current to the lights, I know I am doing somthing wrong I just need someone to tell me what I messed up here.

Blake

 

[fireman74201]

what is the voltage of the lights u installed

 

[JarheadMtn]

Did you test the lights off of the battery to see that they work? Are they grounded to the bumper when you mounted them? Possibe that the paint is not allowing the light to ground itself on the metal bumper?

 

[A/C Cages]

You try testing a light by itself to the battery to make sure they work correctly? Dont laugh, ive hooked up flood lights on the Hummer and took me an hour to figure out I never installed the bulbs in them yet... Yeah I was laughing AFTER. lol

Its sometimes the simplest things you never see.

 

[big block 88]

I hooked the lights up as 12 volt and they work but they are very dim, they do NOT respond to the 24 volt hook up I have to be doing something wrong.

The lights are 24 volt I'm pretty sure atleast they are lights that magnet mounted for use on 50 cal's for spot lights. I removed the magnets and bolted them directly to the bumper.

 

[cpf240]

Silly question... have you verified you are getting 24v to and out of the switch?

 

[plym49]

Can't tell from your diagram - do you have the correct connections at the batteries? If so, then here is how to troubleshoot the circuit:

1 - Jumper the switch with a test lead (alligator clips). Do the lights light? If yes, bad switch, if not continue.

2 - With a test light or a volt meter, check for +24v at the hot side of the switch. If not, then the problem is between there and the positive battery terminal.

3 - If that was not it, check for +24 volts at the hot side of the lights with the switch on. If not, problem is between there and the other side of the switch.

4 - If that was not it, run a jumper from the other side of the lights to truck ground. If they light, then the problem is with the wire running back to the - terminal of the battery.

5 - If the voltages check out everywhere according to the above, then all three lights are burnt out.

 

[big block 88]

I will check the switch but even when I eleminated the switch the lights still didn't come on in 24 volt, I must have the connections wrong at the batteries.

My sketch at the top is pretty crappy but it shows how I hooked up my wires. I am pretty sure it is wrong all I did was hook my hot wire to the positive terminal on bettery 1 and my ground wire to the negative terminal on battery 2.

How is it getting 24 volts in my head the serieis is NOT complete by wireing it the way I did as the batteries are not in a series I don't think.

 

[cpf240]

How is it getting 24 volts in my head the serieis is NOT complete by wireing it the way I did as the batteries are not in a series I don't think.

If there is no connection between the two batteries, neg to pos, to complete the series circuit, then no, this won't work. I was thinking that the drawing was just incomplete, not showing the interconnection of the batteries. Perhaps there is more then is depicted in the drawing?

 

[deuceaid]

 

[plym49]

I will check the switch but even when I eleminated the switch the lights still didn't come on in 24 volt, I must have the connections wrong at the batteries.

My sketch at the top is pretty crappy but it shows how I hooked up my wires. I am pretty sure it is wrong all I did was hook my hot wire to the positive terminal on bettery 1 and my ground wire to the negative terminal on battery 2.

How is it getting 24 volts in my head the serieis is NOT complete by wireing it the way I did as the batteries are not in a series I don't think.

First item I mentioned in my reply - check the batteries first. Do you have 24v across where you tapped in to hook up your wires?

Not sure why you ran all the way back to the batteries, anyway. An alternative is to grab 24v under the dash, ground the lights to the chassis (one less wire to run) and unless you are using gigunda wire and a very manly switch you are going to see a voltage drop. Suggest adding a relay. If you run a relay than you can pick off the 'heavy' current for the lights (relay switched circuit) from the starter or alternator terminals under the hood.

 

[big block 88]

If there is no connection between the two batteries, neg to pos, to complete the series circuit, then no, this won't work. I was thinking that the drawing was just incomplete, not showing the interconnection of the batteries. Perhaps there is more then is depicted in the drawing?

No sir the drawing is excactly how it is hooked up. The batteries do have there crossover wires to complete 24 volts to the trucks electronics I just ran 2 wires from my light that are in a series, one is positive wire the other is a negative and wire. All I did was run the positive wire to the positive terminal and the negative wire to the negative terminal.

The reason I ran all the way to the batteries is because the truck has about 12 more lights going on it, 3 more on the front 4-5 on the roof, 4-5 under the bed shining backward, so I wanted a dedicated harness for all the voltage it will require as well as multiole switches to control what lights are on and when.

I will check all voltages with an ohmeter on monday I have to work tomorrow, these holidays are pretty tough on a guy off for 7 days then work 1 off for 5 days then off 5. Goes this way for the better part of 2 months so if the weather will hold out I can get this all buttoned up.

 

[plym49]

No sir the drawing is excactly how it is hooked up. The batteries do have there crossover wires to complete 24 volts to the trucks electronics I just ran 2 wires from my light that are in a series, one is positive wire the other is a negative and wire. All I did was run the positive wire to the positive terminal and the negative wire to the negative terminal.

The reason I ran all the way to the batteries is because the truck has about 12 more lights going on it, 3 more on the front 4-5 on the roof, 4-5 under the bed shining backward, so I wanted a dedicated harness for all the voltage it will require as well as multiole switches to control what lights are on and when.

I will check all voltages with an ohmeter on monday I have to work tomorrow, these holidays are pretty tough on a guy off for 7 days then work 1 off for 5 days then off 5. Goes this way for the better part of 2 months so if the weather will hold out I can get this all buttoned up.

If you are going to run that many lights they should be controlled by relays. They will be drawing a lot of current. The switches control the relays; each relay can switch one set of lights.

If you are dead set against relays, then run a really heavy wire (think a motorcycle battery cable) from the + side of your battery to a dedicated terminal strip. Jumper the hot across one side of each terminal - if you have a ten terminal strip, then to all ten. Then, run the other connection to each switch, ideally through a circuit breaker or fuse. Ground the lamps and you are done.

Use a voltmeter to check your circuit, since there will be power in the circuit. Ohmmeters check resistance, and the item being checked should not be powered on. You might have a multimeter - switch it to 'volts' for your diagnostics. A common use for the multimeter on the 'ohms' range is to check the operation of a switch (that is not wired up) to confirm it is good.

Do yourself a favor and ground your lights to the chassis. It eliminates half of the wiring you are going to run, and you will not find as large a wire as your entire truck.

 

[big block 88]

Sorry I meant volt meter I was using an ohmeter earlier and i typed it I guess.

Anyway I think I will be grounding to the chassis as I have found an excellent ground location. I'm not against relay's in any way just never really thought about them. I am running a pretty healthy wire not sure on the gauge but it's about 5/16 in diameter.

Thanks for all the help here fellas.

 

[A/C Cages]

So how did it go? Did you get the bugs worked out and are the light on now?

 

[Wildchild467]

If you had your 3 lights in the front hookedin serie and 24 volts powering them, that woud not be the same as your drawing. Your drawing snows a paralle circuit. So if you did have them hooked in series that means each bulb is getting about 8 volts each on a 12 volt bukb explaining why they are dim.

 

[Wildchild467]

And another thing, if those are 12 volt bulbs and you have them hooked up to the 24 volts like in your diagram, that would be too much voltage and blow all your bulbs fast... so i think you need to remove one of the lights in your circuit and then report back... i bet it will work better then because each 12 volt bulb will split the 24 volts to make 12.

 

[OldDominionIron]

I don't know what the current draw is for the lights, but make sure your switch is rated for it. I bought a 24V switch from RS that is rated for 50 amps. Check the continuity through your switch, that might be the problem (even if it's a new switch, it might have a defect).