Posted 2006-01-28 3:53 PM (#36126) Subject: Loading lights used as back up lights
Member
Posts: 15
Location: East Haddam Connecticut
I have rear loading lights on the trailer that are controlled by a single pole switch at the rear outside of the trailer. Is there a way to have the rear loading lights come on with the reverse lights on the truck and also keep the ability to turn them on manually like they are wired now?
Posted 2006-01-28 6:59 PM (#36131 - in reply to #36126) Subject: RE: Loading lights used as back up lights
Expert
Posts: 2953 Location: North Carolina
The easiest way I can think of is a 12 volt dc relay. Wire the relay coil to the back-up light circuit. Have the normally open contacts parallel to the single pole switch.
When the back-up light circuit energizes the relay coil, the NO contacts will close, turning on your rear loading lights. Yet, the built-in switch will still function as it did, before your bright & good idea.
Posted 2006-01-28 9:04 PM (#36135 - in reply to #36126) Subject: RE: Loading lights used as back up lights
Veteran
Posts: 143 Location: southeast U.S.A.
I have the rear load lights on our trailer and have intended to do the same thing soon as I can get around to it.
You can replace the single poll switch with a single poll/double throw/center off switch and then leave it in the b-up position under normal use and then switch it to load lights when needing them from the back of the trailer.The switch would be wired with the back-up on one of the outside polls/ the load lights on the other outside polls and the center poll being for the light itself. This would require that you have a 7-way R.V.type plug and most likely an extra wire for the back-up lights running back to them for the trailer.Most of the horse-trailers that i'm familiar with only carry 5 or 6 wires from the factory.Done this on my previous trailer and it worked out great.
Posted 2006-01-28 10:16 PM (#36137 - in reply to #36135) Subject: RE: Loading lights used as back up lights
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Posts: 2689
Just be sure you know what your current(pun) wiring is.
Electric brake (usually a blue wire) is often swapped for the back-up light wire. See e-trailer.com for the various "standards", figure out which one your truck and trailer are.
Yes, loading ramp light to center pole on a 2 way switch, existing power to one pole, back-up light line to the other. In one position it is "ON", in the other position it is ON if the truck is in reverse. You don't need a center off switch, or a relay. I like the radio shack all plastic switches, nothing to rust or corrode against aluminum.
BTW, don't expect to "see" anything very much with this set up.
The load ramp light shines onto an area that you just can't see when backing up. It IS useful as a warning light - ONLY ! but there are good reasons for not backing out into traffic that needs such warning (-:
I also have rubber "tractor lights" on each side of the big trailer, they're mounted well forward and aimed at the trailer's wheels, which is what I try to "position" when backing up - not the back of the trailer.
Posted 2006-01-29 2:00 AM (#36146 - in reply to #36126) Subject: RE: Loading lights used as back up lights
Member
Posts: 15
Location: East Haddam Connecticut
I have done more research on my project and I have a few more questions. First of all it seems easier just to get out of the truck and turn on the load lights when I need to back up in the dark,but I love automation. I do have a 7 pin connector and the middle pin is a live 12 volt feed for the interior and load lights. A Ford truck pulls this trailer so the feed is only live when the key is in the run position. The load lights are 55 watts each. Can I add 110 watts to the reverse circuit of the truck without blowing a fuse? If not, a relay mounted in the truck must be used. I hope this is not the case. The common terminal of the relay would be be connected to a dedicated fused circuit and the load lights. The existing feed to the light switch would have to be disconnected. It seems that 2 more wires would have to be run from the relay to the trailer. One for a live feed to any of the 3 types of switches from the (N.C. power open) contact and one to the lights or the 2 or 3 way switch from the (N.O. power close) contact. Does this sound correct? I have been told by the dealer that the live feed from the connector does not charge the breakaway battery. The posts I have read say that the live feed does charge the battery,but which one? Are they talking about the breakaway battery or the battery used in LQ trailers to power lights and other 12 volt sources. Thanks again.
Posted 2006-01-29 8:35 AM (#36149 - in reply to #36146) Subject: RE: Loading lights used as back up lights
Expert
Posts: 2689
Originally written by nerspellsner on 2006-01-29 3:00 AM
I have done more research on my project and I have a few more questions. First of all it seems easier just to get out of the truck and turn on the load lights when I need to back up in the dark,but I love automation. I do have a 7 pin connector and the middle pin is a live 12 volt feed for the interior and load lights. A Ford truck pulls this trailer so the feed is only live when the key is in the run position. The load lights are 55 watts each. Can I add 110 watts to the reverse circuit of the truck without blowing a fuse? If not, a relay mounted in the truck must be used. I hope this is not the case. The common terminal of the relay would be be connected to a dedicated fused circuit and the load lights. The existing feed to the light switch would have to be disconnected. It seems that 2 more wires would have to be run from the relay to the trailer. One for a live feed to any of the 3 types of switches from the (N.C. power open) contact and one to the lights or the 2 or 3 way switch from the (N.O. power close) contact. Does this sound correct? I have been told by the dealer that the live feed from the connector does not charge the breakaway battery. The posts I have read say that the live feed does charge the battery,but which one? Are they talking about the breakaway battery or the battery used in LQ trailers to power lights and other 12 volt sources. Thanks again.
The 12 volt feed (black wire opposite the white ground wire) on a 7 pin plug is the one that charges the breakaway battery. The center pin is also 12 volt and is often recognised as the "AUX" for providing DC power around the trailer. You basically have a contest of three functions for two pins, many people make the AUX and 12v wires one to free up a pin for back-up, usually the center pin.
I don't know why you have 55 watt lamps, that is about HEADLIGHT HIGH BEAM power, not something I want to walk a horse into. Anyway, they probably only draw 4 amps each, so two of them shouldn't be blowing fuses. Again, I don't think relays are needed, this is LOW current.
Posted 2006-01-29 3:32 PM (#36173 - in reply to #36149) Subject: RE: Loading lights used as back up lights
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Posts: 2953 Location: North Carolina
Originally written by Reg on 2006-01-29 7:35 AM
... I don't know why you have 55 watt lamps, that is about HEADLIGHT HIGH BEAM power, not something I want to walk a horse into. Anyway, they probably only draw 4 amps each, so two of them shouldn't be blowing fuses. Again, I don't think relays are needed, this is LOW current.
Reg .. I would disagree and strongly recommend a relay with the additional wattage information just given. watts/volts = Amps 110 total watts divided by 12 volts = 9.2 amps. This amount of power will be hard on the trucks contacts that were designed for the truck's back-up lights. A generic relay now will be a lot less expensive than a Ford relay and a burnt Ford wiring harness in the future.
Posted 2006-01-30 9:40 AM (#36209 - in reply to #36173) Subject: RE: Loading lights used as back up lights
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Posts: 2689
Originally written by hosspuller on 2006-01-29 4:32 PM
Originally written by Reg on 2006-01-29 7:35 AM
... I don't know why you have 55 watt lamps, that is about HEADLIGHT HIGH BEAM power, not something I want to walk a horse into. Anyway, they probably only draw 4 amps each, so two of them shouldn't be blowing fuses. Again, I don't think relays are needed, this is LOW current.
Reg .. I would disagree and strongly recommend a relay with the additional wattage information just given. watts/volts = Amps 110 total watts divided by 12 volts = 9.2 amps. This amount of power will be hard on the trucks contacts that were designed for the truck's back-up lights. A generic relay now will be a lot less expensive than a Ford relay and a burnt Ford wiring harness in the future.
Well... Yes, no and maybe.
I've always assumed that the wattage rating is taken at a supply voltage that the running vehicle will most likely supply, i.e. something over 14 volts. So 55 watt lamps are likely to draw something under 4 amps each. Yes, I've messed around with headlight bulbs as load resistors in EE 101.
I'm running 3 "rubber tractor lights" in this configuration, one over the ramp for signalling (and becasue it was "there" as a loading light) and one on each side to see where my wheels go. They're 35 watt each, so at 105 watts I'm running a comparable load.
The trailer connection for back-up lights is fused at 10 amps on my truck. This isn't just a daisy chain off the little lamps on the back of the cab, it is for supplying some reasonable amount of power to back-up lights on a trailer.
If the Ford in question is wired similarly the O/P could (in theory at least) run 140+ Watts off the back-up wire that is in the trailer connector.
"Fuses are there to protect the wiring, not the load." Though I don't remember the source of that quote I DO remember the principle. Burning up a wiring harness is only likely if the fuse protecting it is too high, e.g. 22 guage wiring "protected" by a 50 amp fuse (-:
In these days of product liability I'd guess the contacts and wiring could take MUCH more than the (overly protective) fuses would allow.
In any case, the price of a relay is trivial if it provides some peace of mind, probably a good investment for that reason alone. I'm just saying that it isn't needed, I haven't found it to be needed in a similar case, etc.
Posted 2006-01-30 9:52 AM (#36211 - in reply to #36126) Subject: RE: Loading lights used as back up lights
Elite Veteran
Posts: 788 Location: Tenn/Ala.
To the question about charging the brake-a-way battery, you need to check with your trailer manufacturer or dealer. This will depend on how the trailer was designed and wired, and the type of brake-a-way system it has. Most, but not all, manufacturer's non-LQs don't charge the battery. RTSmith
Posted 2006-01-30 11:12 AM (#36216 - in reply to #36211) Subject: RE: Loading lights used as back up lights
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Posts: 2689
Originally written by RTSmith on 2006-01-30 10:52 AM
To the question about charging the brake-a-way battery, you need to check with your trailer manufacturer or dealer. This will depend on how the trailer was designed and wired, and the type of brake-a-way system it has. Most, but not all, manufacturer's non-LQs don't charge the battery. RTSmith
REALLY ?
Wow !!!
That IS a surprise (to ME).
I had thought/assumed that it was somewhere in the Federal CFR / d.o.t. specs or somewhere that the breakaway battery HAD TO BE CHARGED while the trailer was being towed.
Posted 2006-01-30 2:20 PM (#36229 - in reply to #36126) Subject: RE: Loading lights used as back up lights
Veteran
Posts: 143 Location: southeast U.S.A.
Reg,
Your correct,You don't need a center off position. I thought i'd put that feature on mine just for the simple reason that radio shack used to carry this style switch with double polls rated @ 20 amps that you could double up on the polls and be more assured of the connection and just in case i'd like to completly turn off the lights for any reason.But not really any true need for it. Sorry for any confusion,
Posted 2006-01-30 2:25 PM (#36230 - in reply to #36126) Subject: RE: Loading lights used as back up lights
Veteran
Posts: 143 Location: southeast U.S.A.
Also, if my memory serves me correctly,there is allready a dedicated pole on an 7-way R.V. plug for back-up. Shouldn't be any need to make any changes!
Posted 2006-01-30 7:10 PM (#36258 - in reply to #36230) Subject: RE: Loading lights used as back up lights
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Posts: 2689
Originally written by Ardly on 2006-01-30 3:25 PM
Also, if my memory serves me correctly,there is allready a dedicated pole on an 7-way R.V. plug for back-up. Shouldn't be any need to make any changes!
Ardly
Not if you want AUX power and electric brakes (-:
Count 'em, then choose any 7 ;
tail lights
turn/stop left
turn/stop right
+ 12V
ground
so far the 4 pin would have to use the coupler/ball for ground,
it is a very poor ground (on welfare), or not have +12V - this is the usual 4 pin solution, but then you can't charge the breakaway battery.
AUX for trailer internal lights, 12 volt power.
electric brakes
back-up lights.
Well, you can kinda/sorta double up the +12V and AUX together.
Ya probably really need an RV 9 pin, that's N_I_N_E !!!
(-:
Posted 2006-01-30 8:11 PM (#36263 - in reply to #36126) Subject: RE: Loading lights used as back up lights
Expert
Posts: 1283 Location: Home of Wild Turkey Whiskey
I beleive Reg is onto something here. I did the backup lights on another trailer I had. I put the lights toward the front of the trailer aimed at the wheels and I had them on a switch in the truck with a separate connector that I wire tied to my seven pin. Worked fine I like simplicity.
Posted 2006-01-31 9:59 AM (#36290 - in reply to #36126) Subject: RE: Loading lights used as back up lights
Veteran
Posts: 143 Location: southeast U.S.A.
I maybe wrong,don't have the truck at home right now,but it is prewired from the factory (2003 F350) with-tail/left turn-stop/right turn-stop/ground/electric brakes/12v.aux feed that runs the interior lights/back-up.I'm not familiar with the extra feed for the 12volts that you mentioned.My female plug cover has the schematic embossed on it showing only one 12v. feed,the one that runs the interior lights.Thats how I came up with 7.Maybe Ford has it wrong!!!!????But probably they just combined the two 12v.'s to start with.
Loading lights used as back up lights
