12+12=24?

totaljoint · Post by **totaljoint** » Fri Jan 14, 2011 11:23 pm

If I hook two 12V Harbor Freight LED tail lights (same amperage) in series, can I connect that to the 24V system without problem? Isn't the equation the same as hooking the two batteries up in series? Or will I be doing something bad to the harness/fuses/connectors etc..

(I want to put them on top of the rear cage to go on only when the brakes are activated, no turn signals).
Thanks!

Ed

edzz · Post by **edzz** » Sat Jan 15, 2011 12:03 am

Yes you can hook them up in series. Just remember if one fails neither one will light up. Just like some Christmas tree light strings if one bulb burns out none of the bulbs light up.
Ed

krick3tt · Post by **krick3tt** » Sat Jan 15, 2011 12:42 am

Ed,

If you hook them into the stock stop lights (you do have stock tail lights, right) one for each side then, you can install a resistor in line with the 12v lights and not worry about one going out, although with LED it is probably not an issue.

I used a 220 ohm 10 watt resistor. Got them in a two pack from Radio Shack for $.99. I use one on my RPM gage and it is 12V.

I hope that will work for you.

Morris

ccalingaert · Post by **ccalingaert** » Sat Jan 15, 2011 12:57 pm

Since they are LEDs you probably don't need to worry about them burning out as long as you own your pinz. I have 12V LED clearance lights wired in series in the front and back sides of my truck and they work great.

GenevaPinz · Post by **GenevaPinz** » Sat Jan 15, 2011 12:59 pm

krick3tt wrote:Ed,

If you hook them into the stock stop lights (you do have stock tail lights, right) one for each side then, you can install a resistor in line with the 12v lights and not worry about one going out, although with LED it is probably not an issue.

I used a 220 ohm 10 watt resistor. Got them in a two pack from Radio Shack for $.99. I use one on my RPM gage and it is 12V.

I hope that will work for you.

Morris

One thing to remember when installing a resistor is that it will get really hot if the related circuit (lights in this case) remains switched on for some time. Should not be an issue in your case with brake lights.

This is information that I came accross when looking into LED conversion parking lights for my daily driver, and with plastic being everywhere in modern vehicles this is more of an issue than with the all-metal Pinz.

Jan

Thomas-E · Post by **Thomas-E** » Sat Jan 15, 2011 4:07 pm

Make sure that these have two leads on each light, check that there is no grounding circuit in a metal frame. Conventional auto light fixtures have the frame attached to one side of a lamp (- side) and only one lead out of the fixture (+side). If that is how this is setup then you will have to insulate the lamp that is connected to the 24 volt + circuit.

For most LED lamps to work you must connect the + wire to the
+ voltage, if reversed the lamp will not light.
(some very few lamps are built to work either way..very rare)

Series connection works well, just remember if one light fails(not likely) then the other lamp will not work.

totaljoint · Post by **totaljoint** » Sat Jan 15, 2011 6:41 pm

Thank you guys for the input.

Theoretical question:
If a resisitor decreases the amperage, but the voltage will remain the same, so the output wattage will be the same? A resistor will not decrease the voltage (or why would we need 24-12 invertors)?

My current (Jeep style) tail lights use standard 24v bulb, I'm putting in the electronic flasher so that I can use 24v LED bulbs (thinking I'll save some amps for the new LED brake lights).

Since I pretty much run with the lights on all the time, the new LED's will be always on low and only brighten up when the brake pedal is pushed, so then I'll heat up a resistor pretty good, huh?
(maybe use it to help heat the passengers in the back!)
Perhaps a 24v LED is worth the extra $.

But I do want to hear more about the 12v tachometer, that must be on all the time. Where does it hook up to on the engine, where did you mount it and what brand did you use?

pcolette · Post by **pcolette** » Sat Jan 15, 2011 6:58 pm

SAV sells a tachometer:
http://www.pinzgauer.com/showdetails.ph ... no=SAV1404
It is a 12V VDO model but comes with the resistor already installed on input side and a 24V bulb for illumination. It's been a while since I installed it but IIRC it connects to the negative side of the coil.
It can be a bit difficult to install due to the dip switches on it. Some swear by it and others at it

It's worked very well for me.

Paul

edzz · Post by **edzz** » Sat Jan 15, 2011 9:23 pm

totaljoint wrote:Theoretical question:
If a resistor decreases the amperage, but the voltage will remain the same, so the output wattage will be the same? A resistor will not decrease the voltage (or why would we need 24-12 invertors)?

This link may help
http://en.wikipedia.org/wiki/Series_and ... l_circuits

totaljoint wrote:Perhaps a 24v LED is worth the extra $.

Many times it’s less expensive to buy a 24v product designed for the purpose in mind rather than attempt to adapt a 12v product and risk letting all the smoke out. Having training and experience in electronics engineering (jack of all trades) I can design or adapt items from one voltage to another however it is commonly easer and less expensive for me to simply purchase off the rack 24v devices.

Ed

totaljoint · Post by **totaljoint** » Sat Jan 15, 2011 9:37 pm

Aircraft spruce has a tachometer that reads RPM off the propeller.
In our Pinzgauer, is one revolution of the fan=to one revolution of the crank shaft? Could that be an easy way to read the engine RPM: set up the sensor to read the fan RPM?

krick3tt · Post by **krick3tt** » Sat Jan 15, 2011 9:38 pm

Try here, it's where I get my stuff for lights

http://grote.com/America/

chacaocop1 · Post by **chacaocop1** » Mon Jan 17, 2011 9:00 pm

totaljoint wrote:Thank you guys for the input.

Theoretical question:
If a resisitor decreases the amperage, but the voltage will remain the same, so the output wattage will be the same? A resistor will not decrease the voltage (or why would we need 24-12 invertors)?

http://www.csgnetwork.com/ohmslaw2.html

Check the formulas, as long as you connect it in series it will do so. The voltage can be decreased with the use of a resistor, the resistor of course needs to withstand the power that will flow through it.

totaljoint · Post by **totaljoint** » Tue Jan 18, 2011 5:44 pm

Thanks, everyone!!
I had the wrong formula:
Volts=amps x resistance: that is where the resistor comes in.
I don't know "Watt"

I was thinking about!

Although there are some decent deals on 24V LED tail lights on ebay right now-- all from Australia.
Any one have experience with them? I'm hesitant as recent news suggests they might be a little wet.

chacaocop1 · Post by **chacaocop1** » Tue Jan 18, 2011 8:00 pm

http://www.sportsimportsltd.com/24vosubr24le.html

Try this site. Local, cheap, 24V. You won't need thew formulas.

totaljoint · Post by **totaljoint** » Tue Jan 18, 2011 9:02 pm

Great deal on the LED bulbs, thanks! (too bad they're sold out of 24v right now)

Do most of you use the SAV trailer light plugs:
http://www.pinzgauer.com/showdetails.ph ... no=SAV1004
and wire your own, or:

the 7 round pin range rover plugs that have the 4way flat connector built in? Example:

http://cgi.ebay.com/ebaymotors/7-ROUND- ... ccessories
or:
http://tweetys.com/7pintype-4adapter.aspx

THE PORTAL HUB - Pinzgauers, Haflingers, Volvo 303s and more!

12+12=24?

12+12=24?

12 + 12 = 24

Re: 12 + 12 = 24

Tail-lights

12 + 12 = 24

Trailer light plug