| Author | Message | ||
| Bill Holstein (Billmoocow)
Registered Member Username: Billmoocow Post Number: 59 Registered: 5-2009 Posted From: 98.232.207.25  Rating: N/A |
Everything nowadays is 12 volt it seems. All the big rigs are 12 volt and all the new busses are. It is cheaper to buy 12 volt bulbs too. Question: would it be feasable to convert to 12 volt from 24? Or is it better to leave the it? The coach house is on a 12v system that i intalled and working good. Every time i try to go to a semi tractor part store and ask about 24 volt stuff, they have that deer in the head light look. You know what i mean? | ||
| Cory hart (Chart1)
Registered Member Username: Chart1 Post Number: 24 Registered: 1-2010 Posted From: 12.108.83.2  Rating: N/A |
I converted mine to 12 volt.. The only thing I have left that is 24 volt is running lights and tail and turn signals. Oh and bus starter. I also took the gear driven alternator off and put 2 belt driven alternators off the front pullys. 1 is a 12v and 1 is a 24v. Very easy to change if needed and a new one is 100.00 for either. | ||
| John MC9 (John_mc9)
Registered Member Username: John_mc9 Post Number: 1105 Registered: 7-2006 Posted From: 74.162.78.89  Rating: N/A |
The 24vdc sockets for many of the 24vdc bulbs are different than the 12vdc sockets, but of you're going to change the entire holder, why not go to LED lights and get it over with. I had been planning to leave the 24vdc gen in the bus, and add a 12vdc alternator to the engine. It was easy to make the bracket, and plenty of space to mount it where the OE AC compressor came out. The LED lights are a lot less expensive today, and they can be run on 12 or 24vdc. The life expectancy is less when run at a higher voltage, but a few years out of the 10 or so isn't that bad.... | ||
| Ralph Peters (Ralph7)
Registered Member Username: Ralph7 Post Number: 106 Registered: 3-2004 Posted From: 75.245.188.213 Rating: N/A |
The only 24V on our bus, guages, starter,60A alt. 1 used 200A relay (from old AC box). I rewired light sockets with used pigtails, also headlights were rewired, dimmer switch needed rewired. Clearence are sealed units from Walley-world. Also drive 12V & 24V alt's off old AC groves. | ||
| Len Silva (Lsilva)
Registered Member Username: Lsilva Post Number: 345 Registered: 12-2000 Posted From: 72.187.35.208  Rating: N/A |
You must be careful converting from 24 to 12 as the wire size may be too small. Using LED's eliminates that problem. Converting the engine to 12 volt would be a project; starter, solenoids, skinner valves, gauges etc. | ||
| Tom Christman (Tchristman)
Registered Member Username: Tchristman Post Number: 201 Registered: 1-2006 Posted From: 66.218.33.156 Rating: N/A |
Both my bus and truck run on straight 12vdc. Of which was a serious point when I first bought the bus. Personally-I'd like to see all big rigs and buses run on 24v, but big rigs continue with 12v. Good Luck, TomC | ||
| George M. Todd (George_todd)
Registered Member Username: George_todd Post Number: 966 Registered: 8-2006 Posted From: 99.172.180.138 Rating: N/A |
This has been in the archives several times. A 24 to 12 changeover will require almost doubling the size of every cable in the bus, not to mention a lot of the smaller wires. Then you will have to buy an alternator, regulator, starter, solenoid, every light bulb in the bus, plus the skinner valve, the high idle valve if you have one, and the Jake solenoids if you are equipped. Next comes the low air warning buzzers, followed by headlight relays and horn relays. Then try to start a 12Volt Detroit in cold weather. We all know what a Trace SW4024 is, but an SW 4012 doesn't exist, because of cable size requirements! (4000 Watts at 12 Volts requires 334 AMPS with a perfect inverter, which doesn't exist!) Sorry to rain on your campfire, but now that its in perspective, you'll enjoy buying a very FEW 24V bulbs. G | ||
| R.C.Bishop (Chuckllb)
Registered Member Username: Chuckllb Post Number: 1187 Registered: 7-2006 Posted From: 75.245.156.180 Rating: N/A |
 ...that's our G... RCB | ||
| Bill Holstein (Billmoocow)
Registered Member Username: Billmoocow Post Number: 62 Registered: 5-2009 Posted From: 98.232.207.25 Rating: N/A |
George, That was the answer i wanted. Down to the point. Is there any store/place that stocks the bulbs we need for our busses? Also, doesnt it seem weird that the more voltage you have the smaller the wiring. That breaks the common sence barrier. A person would think that the more voltage, the bigger the wire. Instead of going from 24 volts to 12 volts, thinking youre safe. A person would assume (me being the a..,) that 24 volts would push more amps as well. | ||
| Patrick levenson (Zubzub)
Registered Member Username: Zubzub Post Number: 200 Registered: 5-2007 Posted From: 174.91.225.235  Rating: N/A |
Bill, Ohm's law In electrical circuits, Ohm's law states that the current through a conductor between two points is directly proportional to the potential difference or voltage across the two points, and inversely proportional to the resistance between them, provided that the temperature remains constant. i know that's a mouthful, just ponder it a bit and you'll "see" why the wire needs to be bigger to carry the same amps at a lower voltage.....at least I think you will. This link might help http://people.seas.harvard.edu/~jones/es154/lectures/lecture_2/Ohm'sLaw/Ohm'sLaw.html This link might help. it helps to have a little theory, but here's a little practical link. http://www.matronics.com/aeroelectric/articles/wiresize.pdf (Message edited by zubzub on March 29, 2010) (Message edited by zubzub on March 29, 2010) | ||
| Tim Brandt (Timb)
Registered Member Username: Timb Post Number: 512 Registered: 10-2003 Posted From: 66.165.176.62  Rating: N/A |
Bill, An easy way to think of it is if you are doubling the voltage you are cutting the current required in half. So the reality is you are sizing the wire to the amperage not the voltage | ||
| Brian Elfert (Belfert)
Registered Member Username: Belfert Post Number: 87 Registered: 7-2006 Posted From: 75.72.107.232 Rating: N/A |
C&J Bus Repair in Minneapolis should have any 24 volt bulb you need. 952-881-0034. Luke at US Coach probably has them too. My bus has all 12 volt lights on the outside, but for some reason they choose to use 24 volt bulbs for the dash and the luggage bays. | ||
| Dale Waller (Happycampersrus)
Registered Member Username: Happycampersrus Post Number: 379 Registered: 7-2005 Posted From: 166.229.0.210 Rating: |
My local NAPA can get any stock 24v bulb that my MCI has, but I did convert all my running lights to 12v sealed LEDs to make sure they will never leak again! It's a lot of work to change a 24v coach to all 12v, plus with the money and time you'll spend/waste you would be far ahead of the game to just stay 24v and order 24v parts as needed. | ||
| George M. Todd (George_todd)
Registered Member Username: George_todd Post Number: 967 Registered: 8-2006 Posted From: 99.37.31.150 Rating: N/A |
Ohm's law, from well over 200 years ago said I=E/R. I being the induced current, E is the voltage (Electromotive force,) and R is the resistance. Nowadays we would say A=V/R, or the amps equals the voltage divided by the resistance. So, if you increase the voltage, or decrease the resistance, the current increases. A 24 Volt light bulb has twice as much resistance as a 12 Volt bulb OF THE SAME WATTAGE. The formula for Watts, the electrical unit of power, is the Amps times the Volts, which is why 24 Volt buses are wired with smaller wire. The same wattage is available with half the amperage. G | ||
| Luvrbus (Luvrbus)
Registered Member Username: Luvrbus Post Number: 870 Registered: 8-2006 Posted From: 74.32.83.4 Rating: N/A |
The Napa store where I live can get any 24v bulb but they are listed in their books as 28v for what ever reason I don't know good luck | ||
| FAST FRED (Fast_fred)
Registered Member Username: Fast_fred Post Number: 1136 Registered: 10-2006 Posted From: 66.82.9.82  Rating: N/A |
The Napa store where I live can get any 24v bulb but they are listed in their books as 28v for what ever reason I don't know Bulbs are rated at the operating voltage , and 28.5 or so is the charging voltage with the engine operating. A look in Grangers will find both 12V and 14V bulbs. The 14V are for things that will operate as the coach rides alternator on.. The 12V is for reading lamps and over the stove lights that will probably be on while camping. Loosing 2V is a large percentage of the operating volts , so if that book has been hard to read in the head , get the proper bulb! FF | ||
| Geobus (4108gmc)
Registered Member Username: 4108gmc Post Number: 75 Registered: 6-2004 Posted From: 70.40.234.8 Rating: N/A |
I would like to hear more about LED's. I have a 24v system. Where on my coach would be a good place to use LED's? Do I need to be careful of the voltage rating? Where can I buy LED replacements? Have a great day. | ||
| Jack Conrad (Jackconrad)
Registered Member Username: Jackconrad Post Number: 1263 Registered: 12-2000 Posted From: 173.150.144.106  Rating: N/A |
LEDs are great for all exterior lights except headlights. They can also be used inside for task, mood and general lighting, although I would try one in each interior application before buying a bunch of them. They do produce a "different" type of light. Some will work on both voltages, some won't, you need to check the package for that model. For replacements, do a search on Google for the type of light you are looking for (clearance, tail, brake, interior,etc) Jack (Message edited by JackConrad on April 06, 2010) | ||
| Gus Causbie (Gusc)
Registered Member Username: Gusc Post Number: 1150 Registered: 11-2005 Posted From: 173.202.2.46  Rating: N/A |
Bill, If you think in terms of power it makes more sense. A bulb or motor requires a certain amount of power(Watts)no matter what the voltage. (Volts x amps = power). Think of volts as the force pushing the amps through the wires (I know, I know). With 24v you only have to push 1/2 as many amps through the wires as with 12v. The more amps pushed through the wires the hotter they get. (Think a toaster). The smaller the wire the hotter it gets because the volts are pushing hard but the small wire won't let the amps through. If you changed from 12v to 24v it would work very well because the wires would be larger than necessary. A lot of this has already been posted but I'm trying to simplify as much as possible to make it easier for you. I know the EEs will be on my case now!! | ||
| R.C.Bishop (Chuckllb)
Registered Member Username: Chuckllb Post Number: 1210 Registered: 7-2006 Posted From: 75.211.109.26 Rating: N/A |
Gus...that's my kind of speak....easy, simple. Could be that's why I am not a EE or...a PhD. Having said that... Thank God for them. Kinda like makin' Apple Pie...or a Bouillabaisse...depends on the cook (chef, preparer) RCB | ||
| Gus Causbie (Gusc)
Registered Member Username: Gusc Post Number: 1153 Registered: 11-2005 Posted From: 173.202.40.19 Rating: N/A |
RC, I have nothing against engineers, according to a piece of paper I are one but I don't take it too seriously!! Since I would much rather do mechanical work I always said engineers should be required to do repair and maintenance on anything they design! | ||
| Bill Holstein (Billmoocow)
Registered Member Username: Billmoocow Post Number: 72 Registered: 5-2009 Posted From: 98.232.207.25 Rating: N/A |
Hmm. Im having a brain hemorrhage. Wouldnt 12v "things", take less amps than 24v? | ||
| Bob MacIsaac (Wildbob24)
Registered Member Username: Wildbob24 Post Number: 95 Registered: 5-2007 Posted From: 98.92.170.105  Rating: N/A |
Bill, Ohm's law tell us no. As Tim posted, at a given power level(watts), 12 volts will require twice the amperage as 24 volts. One of the Ohm's law calculators is: Watts = Volts X Amps Example: 24watts = 24volts X 1amp or 24watts = 12volts X 2amps Bob | ||
| Geobus (4108gmc)
Registered Member Username: 4108gmc Post Number: 76 Registered: 6-2004 Posted From: 70.40.234.8 Rating: N/A |
Another way of thinking about this is washing your coach. Yup. Water pressure is the same as voltage. If you have great water pressure (just like a 24V system) you can use a smaller hose (wire) to supply enough water to your pressure washer. If you have low water pressure (just like a 12V system) you need a larger hose (wire) to get enough water. The problem with electrical wires (hose) is that, if the wire isn't big enough, the bulb or motor your are using is still trying to pull/draw (current) enough electricity (water) to operate it like it was designed to. The extra demand heats up the wire and may eventually cause is to fail. Just like your pressure washer, if you do not supply enough water it will likely operate poorly and may burn up the pump. Have a great day. | ||
| Bill Holstein (Billmoocow)
Registered Member Username: Billmoocow Post Number: 73 Registered: 5-2009 Posted From: 98.232.207.25 Rating: N/A |
If 24v is more efficient, then why is everything nowadays made 12v. I do get it now as far as the 12v 24v wire. If a system where 48v, would it run even smaller wire? See what im getting at? | ||
| Sean Welsh (Sean)
Registered Member Username: Sean Post Number: 1066 Registered: 1-2003 Posted From: 67.142.130.47  Rating: N/A |
Bill, things are made in 12v because "that's the way we've always done it" and for no other reason. The military has been on 24v for a long time; if you buy a used military Chevy, for example, it will be all 24v. Europe is also moving towards 24v. But manufacturers here have learned the hard way that Americans are stubborn and resist change, which is why, for example, we use an obsolete and arcane system of measurements while the rest of the modern world uses SI (metric) measurements. -Sean http://OurOdyssey.BlogSpot.com | ||
| Len Silva (Lsilva)
Registered Member Username: Lsilva Post Number: 350 Registered: 12-2000 Posted From: 72.187.35.208 Rating: N/A |
Here is a nice Ohm's law calculator http://www.the12volt.com/ohm/page2.asp In case you are wondering, "E" for voltage actually means "Electromotive force" an early term for volts, and "I" for amps comes from the french "intensité". Another way of looking at Ohm's law is that it takes 1 volt to push 1 amp of current through 1 ohm of resistance. (Message edited by lsilva on April 09, 2010) (Message edited by lsilva on April 09, 2010) | ||
| R.C.Bishop (Chuckllb)
Registered Member Username: Chuckllb Post Number: 1217 Registered: 7-2006 Posted From: 75.245.234.222 Rating: N/A |
Thanx, Len....that's easier....???.....I think... RCB | ||
| Gus Causbie (Gusc)
Registered Member Username: Gusc Post Number: 1155 Registered: 11-2005 Posted From: 72.161.172.62 Rating: N/A |
Cessna aircraft did go to 24v years ago. The reason was the mfg could save money on wiring. The 24v battery was three times the price of the 12v!! | ||
| Bill Holstein (Billmoocow)
Registered Member Username: Billmoocow Post Number: 76 Registered: 5-2009 Posted From: 98.232.207.25 Rating: N/A |
Wow! | ||
| niles steckbauer (Niles500)
Registered Member Username: Niles500 Post Number: 961 Registered: 11-2004 Posted From: 173.78.39.41 Rating: N/A |
It is common knowledge that the state of the art in the automotive world is 42 volt - just a matter of time before it happens - It would also be nice if all the so called engineers would post their PE registrations before they claimed the title of Engineer - Seems its easier said than done - FWIW | ||
| R.C.Bishop (Chuckllb)
Registered Member Username: Chuckllb Post Number: 1220 Registered: 7-2006 Posted From: 75.243.216.66 Rating: N/A |
Respectfully...you would be joking, of course...?! AIR, this is not a For Sale/Purchase forum; what purpose is there in degrading it. "Let the Buyer Beware". FWIW RCB | ||
| Bob MacIsaac (Wildbob24)
Registered Member Username: Wildbob24 Post Number: 96 Registered: 5-2007 Posted From: 98.92.172.106 Rating: N/A |
. (Message edited by wildbob24 on April 10, 2010) | ||
| George M. Todd (George_todd)
Registered Member Username: George_todd Post Number: 982 Registered: 8-2006 Posted From: 99.37.31.150 Rating: N/A |
How many of us remember jumping a 6 volt car with a 12 volt? Many times it was successful, other times bulbs burned out, and there was the occasional battery explosion. 42 on 12 would be an instant explosion. 42 volts will kill a mechanic who has worked up a sweat on a warm day, and touches a hot wire while leaning on the fender. Popular Mechanics Mag had an excellent article on this a while back. G |
