Backup lights

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crash457

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That's an interesting way to wire a relay. Crash makes a great case for NOT using one in this application. Most folks run the fused battery lead to Pin 30. Pins 85/86 are for the lead from the upfitter switch to to actuate the relay switch. 87a isn't an input lead. It's an output and is normally closed when the upfitter switch is off. In other words, when 85/86 aren't on, 87a is hot out. When 85/86 are on, 87a is off and 87 is hot out to your accessory. All you will accomplish by hooking the OEM back up light lead to 87a is have the back up lights on continuously when the upfitter switch is off.

Relay%20Schematics%20-%2012V%205%20Pin%2087%2087a%20-%20eledric.jpg

Great, so you can read the instructions that come with a relay on how they are normally used. That is not the only way to wire them. Relays are an electrical circuit that uses a current source to power a coil to flip a switch. They are not directional. Wiring it the way I stated allows the current from the backup lights to flow from pin 87a (used as in input here) to pin 30 (used as the output here) and light the auxiliary reverse lights when the truck is in reverse. When the upfitter switch is on, current across pin 86/85 closes the relay and allows current to flow from pin 87 (used as in input here) to pin 30 (used as the output here) and light the auxiliary reverse lights regardless if the truck is in reverse or not.
 

GrdnFrmn

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Here's the rub, Crash. You say your way is the proper way to wire a circuit and everything else is half-ass shit, but you also admit that the way you suggest using the relay isn't intended by the manufacturer. Someone might call that half-ass shit. I would not go that far, however, since your circuit will actually work, even if it's off spec.

It's also unnecessarily complex (running an extra hot lead from the battery when the the upfitter switch already provides relayed and fused power) and less reliable (moving parts in relays fail) than a simple two input diode. (I've never seen a diode fail that wasn't blown by hi amps - in which case you'd want the diode to fail to protect the accessories.) Also, if you sell the truck wired that way, I'd guess the next owner would find tracing a fault a real bitch if he expects the battery to run to pin 30.

So there's not much reason to act as if your circuit was inscribed by God and handed to Moses. It's creative, but not elegant and certainly not the only proper way to wire these accessories. To each his own.


Call it arguing if you want, but the relay method is how a proper circuit is designed to work. Whether other ways work or not does not discredit that. Show me any available electronics (not some homemade shit either) that provide two power sources to the same device without the use of a relay, and I'll gladly announce that I am wrong. Until then, stop trying to discredit the right way to do something. I could understand if what I was saying was going to be expensive or difficult to do, but doing it the right way is cheap and simple. I don't' understand why so people are so opposed to it. If you want to half-ass shit together, go for it. I can't stop you, but stop trying to convince others that it's the proper way.

Great, so you can read the instructions that come with a relay on how they are normally used. That is not the only way to wire them. Relays are an electrical circuit that uses a current source to power a coil to flip a switch. They are not directional. Wiring it the way I stated allows the current from the backup lights to flow from pin 87a (used as in input here) to pin 30 (used as the output here) and light the auxiliary reverse lights when the truck is in reverse. When the upfitter switch is on, current across pin 86/85 closes the relay and allows current to flow from pin 87 (used as in input here) to pin 30 (used as the output here) and light the auxiliary reverse lights regardless if the truck is in reverse or not.
 

crash457

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Here's the rub, Crash. You say your way is the proper way to wire a circuit and everything else is half-ass shit, but you also admit that the way you suggest using the relay isn't intended by the manufacturer. Someone might call that half-ass shit. I would not go that far, however, since your circuit will actually work, even if it's off spec.

It's also unnecessarily complex (running an extra hot lead from the battery when the the upfitter switch already provides relayed and fused power) and less reliable (moving parts in relays fail) than a simple two input diode. (I've never seen a diode fail that wasn't blown by hi amps - in which case you'd want the diode to fail to protect the accessories.) Also, if you sell the truck wired that way, I'd guess the next owner would find tracing a fault a real bitch if he expects the battery to run to pin 30.

So there's not much reason to act as if your circuit was inscribed by God and handed to Moses. It's creative, but not elegant and certainly not the only proper way to wire these accessories. To each his own.

You're mixing my quotes on two different topics. Wiring two power sources to one device without a relay or a diode is half ass. Your suggestion for a 2 input diode will work, assuming you want to spend as much for one diode as I can get 10 relays for.
And let's be honest, you criticize me for stating my way is correct, yet you have done the same.

Now in this case were not dealing with a high amp circuit, so both will work. However, a diode will only limit the directional flow of current. It will not stop you from overpowering the load if both power legs provide too much amperage at the same time. Based on that alone, in theory a diode is not the proper wiring solution.
 
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Spartan1

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Thanks Lottp,

I ordered the harness which should help me avoid some work. I see what you mean about needing a spacer of some kind. I am trying to come up with a good solution. I bet 3M or somebody makes some sort of dense foam that is adherent so that I can stick it on the back of the included brackets and clear the bolts and bracket on the truck but I wonder if the tailgate will clear it. This should be interesting. Thanks again.
 

NDO

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You're mixing my quotes on two different topics. Wiring two power sources to one device without a relay or a diode is half ass. Your suggestion for a 2 input diode will work, assuming you want to spend as much for one diode as I can get 10 relays for.
And let's be honest, you criticize me for stating my way is correct, yet you have done the same.

Now in this case were not dealing with a high amp circuit, so both will work. However, a diode will only limit the directional flow of current. It will not stop you from overpowering the load if both power legs provide too much amperage at the same time. Based on that alone, in theory a diode is not the proper wiring solution.

This one confused me. Isn't the load determined by the...uh...load? Not the source? If you draw too much with your load you'll blow a fuse or burn a wire if your source is undersized, but having too much amperage "supplied" (i.e. available) doesn't make the load draw any more, does it?

I think it makes sense to use diodes when trying to prevent backfeeds, and relays when trying to provide switched power, particularly on high current systems.

I wired my LED backups straight to an upfitter switch because I only need the brights when backing up my boat, but I used a combination of relays and diodes on my forward light circuits to give me some options on combining lights. I don't think either solution is "wrong", but I think minimizing long wire runs is a good way to go.
 

Spartan1

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I just completed the install on my PUTCO switchblade tailgate lightbar. This thing is great. I ordered a harness that made the install pretty painless. It has running lights, backup lights, turn signal lights, break lights, and hazards. This bad boy is plenty bright for me for a reverse light and looks great on the truck. Chrome Trim, LED Lighting, Car Accessories, Truck Accessories, and Grilles from Putco. I didn't want to light up my neighbors whole house every morning with baja designs reverse lights. I bet that this thing wound even work well for an off road event but if not you could just slap on a hitch style light also. They have a video on their site to show how it looks and functions.
 

OBXRAPTOR17

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Thanks Lottp,

I ordered the harness which should help me avoid some work. I see what you mean about needing a spacer of some kind. I am trying to come up with a good solution. I bet 3M or somebody makes some sort of dense foam that is adherent so that I can stick it on the back of the included brackets and clear the bolts and bracket on the truck but I wonder if the tailgate will clear it. This should be interesting. Thanks again.

I used EPDM adhesive sheeting and cut to the brackets- looks like an OEM solution and should hold up very well for life of truck. Amazon order.
 

marsh1

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I see two version on the Putco web site. Was the one you installed the 60" Blade style. It has this note. Also a link to the instructions below. No mention of the adapter harness needed. The 48" Pure LED one does

Our new part# 92009-60 will work on New Ford F150/Super Duty equipped with "Lane keeping systems" or any other "Trailer Tow package".

http://www.putco.com/documents/instructionfile/92009I.pdf
 
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Spartan1

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Yes I installed the 92009-60. It is very nice for the price.

About 10 posts up in this thread before the battle of the electricians, the poster lottp told me about this harness that worked perfectly.

CURT 7-pin plug-and-play T-Connector (P/N: 55384):
https://www.amazon.com/CURT-55384-Cu...keywords=55384

It plugs in-between the 7-pin connection under your truck (behind the bumper, next to the spare tire).

The attached 4-pin connector on the CURT harness plugs right in t the LED bar, then you tap in the reverse light wire to the center wire on the 7-pin portion of the same harness. Since I have the BLISS pro trailer option, I did have to do a power connection under the dash so that it wouldn't detect anything and still provide a 12V source (their included instructions show you how to do this).
 
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