Adding backup lights
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Laughing Gas
Joined: May 2006
Posts: 1,209
Likes: 69
From: land of 10,000 lakes
Adding backup lights
<hr> <!-- Message body --><!-- google_ad_section_start --> I am adding some back up lights to my truck....I found out the other day that it really sucks trying to backup a trailer up while dark and raining!!
I don't want to have them come on with the backup lights all the time, only with a switch that I will install for them.
This was how I was thinking of wiring them up.....12v from battery...inline fuse.....on/off switch with indication light.....to lights at hitch.....and ground where necessary...
OR with a relay so I cant accidentally leave them on...
85-ground
30-fused 12v from battery
87-aux lights
86-12v from ignition to switch to 86
Sound about right?
Which one is the best way to go?
Also what size fuse do I need (lights are 55w each, total of two lights)...I picked up a 30a fuse, also got 14g wire...
I'm open to any suggestions or comments
Thanks for your help!
Josh
I don't want to have them come on with the backup lights all the time, only with a switch that I will install for them.
This was how I was thinking of wiring them up.....12v from battery...inline fuse.....on/off switch with indication light.....to lights at hitch.....and ground where necessary...
OR with a relay so I cant accidentally leave them on...
85-ground
30-fused 12v from battery
87-aux lights
86-12v from ignition to switch to 86
Sound about right?
Which one is the best way to go?
Also what size fuse do I need (lights are 55w each, total of two lights)...I picked up a 30a fuse, also got 14g wire...
I'm open to any suggestions or comments
Thanks for your help!
Josh
Postmaster
Joined: Aug 2003
Posts: 2,977
Likes: 1
From: South Texas
you don't need to run the power all the way to the battery, you can tie into the trailer plug power and use the relay.
I have "white knight" back up lights, work great. The housing fits around the hitch and has a switch on the backside for on, off, or on with backup lights only.
I have "white knight" back up lights, work great. The housing fits around the hitch and has a switch on the backside for on, off, or on with backup lights only.
MSEE
Joined: Apr 2004
Posts: 10,386
Likes: 35
From: Austin, TX
Hi Josh,
The relay setup you described is what you want. You can find a 30 amp automotive SPST relay pretty easily. As for the current, each light is rated at 55W, that means you will be dissipating 110W of power, at 12V that is around 10 amps pulled through a single conductor. I am assuming that the 55W rating is for a 12V system (you should verify that). 14 gauge wire should be plenty for that. However I would go with a smaller fuse than 30, because 30 amps is about the limit I would put for 14 gauge. I would go for a 20 amp fuse myself; those are plenty common and easy to find.
The relay setup you described is what you want. You can find a 30 amp automotive SPST relay pretty easily. As for the current, each light is rated at 55W, that means you will be dissipating 110W of power, at 12V that is around 10 amps pulled through a single conductor. I am assuming that the 55W rating is for a 12V system (you should verify that). 14 gauge wire should be plenty for that. However I would go with a smaller fuse than 30, because 30 amps is about the limit I would put for 14 gauge. I would go for a 20 amp fuse myself; those are plenty common and easy to find.
Token Redneck
Joined: Jun 2007
Posts: 9,331
Likes: 341
From: Breckenridge, TX
https://www.ford-trucks.com/forums/5...with-pics.html
This guy and the rest of the thread will answer anything you want to know.
Go with the relay IMO. I used cheapo fogs from wal mart and zip tied them to the drawbar and they work just fine.
This guy and the rest of the thread will answer anything you want to know.
Go with the relay IMO. I used cheapo fogs from wal mart and zip tied them to the drawbar and they work just fine.
Thread Starter
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Laughing Gas
Joined: May 2006
Posts: 1,209
Likes: 69
From: land of 10,000 lakes
Hi Josh,
The relay setup you described is what you want. You can find a 30 amp automotive SPST relay pretty easily. As for the current, each light is rated at 55W, that means you will be dissipating 110W of power, at 12V that is around 10 amps pulled through a single conductor. I am assuming that the 55W rating is for a 12V system (you should verify that). 14 gauge wire should be plenty for that. However I would go with a smaller fuse than 30, because 30 amps is about the limit I would put for 14 gauge. I would go for a 20 amp fuse myself; those are plenty common and easy to find.
The relay setup you described is what you want. You can find a 30 amp automotive SPST relay pretty easily. As for the current, each light is rated at 55W, that means you will be dissipating 110W of power, at 12V that is around 10 amps pulled through a single conductor. I am assuming that the 55W rating is for a 12V system (you should verify that). 14 gauge wire should be plenty for that. However I would go with a smaller fuse than 30, because 30 amps is about the limit I would put for 14 gauge. I would go for a 20 amp fuse myself; those are plenty common and easy to find.
https://www.ford-trucks.com/forums/5...with-pics.html
This guy and the rest of the thread will answer anything you want to know.
Go with the relay IMO. I used cheapo fogs from wal mart and zip tied them to the drawbar and they work just fine.
This guy and the rest of the thread will answer anything you want to know.
Go with the relay IMO. I used cheapo fogs from wal mart and zip tied them to the drawbar and they work just fine.
MSEE
Joined: Apr 2004
Posts: 10,386
Likes: 35
From: Austin, TX
Regarding the old Ford relays, it's hard to say. Do they have ratings stamped on them? It is important when you build something to make sure that all components being used are safely within their limitations. Contact current is especially important with relays because of the danger of contacts welding shut. I know that a lot of those old Ford relays were used on things like the horn, which take less current, so I would make sure that whatever you are using is rated for the current you will be working with, with an added safety margin.
Thread Starter
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Laughing Gas
Joined: May 2006
Posts: 1,209
Likes: 69
From: land of 10,000 lakes
Regarding the old Ford relays, it's hard to say. Do they have ratings stamped on them? It is important when you build something to make sure that all components being used are safely within their limitations. Contact current is especially important with relays because of the danger of contacts welding shut. I know that a lot of those old Ford relays were used on things like the horn, which take less current, so I would make sure that whatever you are using is rated for the current you will be working with, with an added safety margin.
It is actually out of my 06....I just added the new towing mirrors with heat and did not have heat before so I needed a new fuse block.....Now I have all kinds of relays and fuses out of the old one....let me see what the manuals says they are for....
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Thread Starter
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Laughing Gas
Joined: May 2006
Posts: 1,209
Likes: 69
From: land of 10,000 lakes
ok it looks like
R01 is starter solenoid, fuse is 101 at 30A
R02 is blower motor, fuse is 116 at 30A
R05 is trailer tow charge, fuse is 106 at 30A (I'm using this relay in the new fuse block)
the rest look to be fuse at 10a .....(accessory delay and hi-beam head lamps)
So I should be good to use any of the top two?...although the part numbers on all of them are the same....
5C3T-14B192-11
P6STD
R01 is starter solenoid, fuse is 101 at 30A
R02 is blower motor, fuse is 116 at 30A
R05 is trailer tow charge, fuse is 106 at 30A (I'm using this relay in the new fuse block)
the rest look to be fuse at 10a .....(accessory delay and hi-beam head lamps)
So I should be good to use any of the top two?...although the part numbers on all of them are the same....
5C3T-14B192-11
P6STD
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MSEE
Joined: Apr 2004
Posts: 10,386
Likes: 35
From: Austin, TX
It is good design practice to size a fuse such that any circuit element downstream of the fuse can short to ground, and the fuse will blow before any element in the path cooks. In a perfect world, this would be the case, but I do not know personally whether or not Ford has done this in every case. I don't like making assumptions..."should be" isn't always "is." Therefore, it's hard to infer a device's amperage rating from the fuse size. Maybe someone more familiar with those part numbers can chime in and tell you if those specific relays are okay to use, but if it were me I'd just use a new relay with specific ratings from the manufacturer. They are abundant and can be had for a few dollars. That way there's no guessing. That's my 2 cents! 
Thread Starter
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Laughing Gas
Joined: May 2006
Posts: 1,209
Likes: 69
From: land of 10,000 lakes
It is good design practice to size a fuse such that any circuit element downstream of the fuse can short to ground, and the fuse will blow before any element in the path cooks. In a perfect world, this would be the case, but I do not know personally whether or not Ford has done this in every case. I don't like making assumptions..."should be" isn't always "is." Therefore, it's hard to infer a device's amperage rating from the fuse size. Maybe someone more familiar with those part numbers can chime in and tell you if those specific relays are okay to use, but if it were me I'd just use a new relay with specific ratings from the manufacturer. They are abundant and can be had for a few dollars. That way there's no guessing. That's my 2 cents!
I will post up pictures when I get them installed in about a week or so.
Thanks again for the help
Josh
Thread Starter
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Laughing Gas
Joined: May 2006
Posts: 1,209
Likes: 69
From: land of 10,000 lakes
Here is for anyone that is following and wants to see the outcome...https://www.ford-trucks.com/forums/738858-auxiliary-backup-lights-installed-how-to-pics.html
I am very pleased with them and they do light of the side of the trailer really good...kind of deceiving in the pictures.
I am very pleased with them and they do light of the side of the trailer really good...kind of deceiving in the pictures.
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