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Discussion Starter · #1 ·
Hey guys, although I'm new to post I have been going thru the threads for a long while. Anyway, I bought some 55 watt "fog" lights to use for my reverse lights while I'm plowing. I have a 2002 Chevrolet 2500HD 6.0 :mad: with a meyer 7 1/2 classic on it. My problem is this, I wired up the lights using a 3 way 25 amp switch so I could leave the lights on or have them go on when in reverse. I also used a 30 amp relay from radio shack and all 12 guage wire. I grounded the lights by the mounting bracket. I used both of these diagrams for wiring it. http://www.letstalksnow.com/forums/showthread.php?t=13172&highlight=switch and http://www.snowplowing-contractors.com/alan_reverse_lights.html . I then started the truck only to see the lights go on while the switch is in the off position. I then turned the switch to where it would have the lights on all the time and it burnt the ground wire within seconds. I went over the wiring about 10 times and it was correct each of the times. I am lost as to why this would happen. Is it possible the relay is no good? Any help or tips would be greatly appreciated. Thanks guys and sorry for the long post

Nick
 

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Hi Nick. What kind of switch is it? Followed Alan's diagram when I wired mine but my switch was different than the one he showed, SPDT. For mine rocked one way is off, middle on in reverse, rocked the other way is from the battery. From what you're describing it could be the same type of switch as mine since with yours in the middle is on with lights and rocked to one side sounds like a straight short. My guess is that if you threw it the other way they'd be out. Probably be worth checking the switch on a bench with an ohmeter or battery and test light/voltmeter to see input/output. Not an expert by any means so hope it makes sense. Don't know about the relay starting out bad. Think it takes a lot to kill one but since it was part of a short circuit probably worth checking it on the bench too.
 

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Discussion Starter · #3 ·
Hey thanks for posting so fast. I almost thought the same thing. The way the switch is according to the package and sticker is on-off-on. Ill try and bench test is tomorrow I guess. Im lost as to why it is doing this. May I ask what you used to power the relay, switch, and stock reverse light signal? Thanks

Nick
 

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Power to the relay should be a fused line form a battery power source. Remember, that is NOT the trigger lead. I can't remember what the numbers are other than 87 (on the normal "ice cube" relay) being the power out.

Reverse signal has to come off a stock reverse light wire AFTER the stock reverse light switch. If you're tying into the reverse circuit ahead of the stock switch you will be getting power to the relay (trigger) all the time when the reverse only position on the toggle is selected.

I take the constant on power for the relay trigger off the same point I get the light power from.

I usually put the relay under the dash somewhere and run power and load wires of #14. Crimped into the terminal for the power lead, along with the #14 I put a #18 or 20 long enough to reach the switch. It helps to have three colors of the lighter wire to keep things straight.

The first light ga. wire goes on one of the ON terminals on the switch.

The second wire comes goes to the Off terminal on the switch.

The wire, which is the third of the light ga. wires, from the existing reverse light lead goes to the remaining ON terminal.

I'm trying to visualize what could be shorting through ground and burning the wire. Coming up blank other than something is not wired right or the switchis not ON OFF ON pattern.
 

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Discussion Starter · #5 ·
Wow, thank you for writing that out for me, I think I figured out what the problem was. I had the wire for the factory reverse lights coming from the fuse under the hood instead of the tail light wire or trailer wire. Do you think that could cause the ground to smoke? Because the reverse wire is getting power at all times? thanks again for the write up

Nick
 

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Nick, need to say I wasn't right before about the switch on its own being a cause for smoke. If my switch were to work as labeled I'd need to switch the "trigger" and back up source wiring in the diagram. Apparently I bought the wrong switch but that wouldn't cause this problem. Kind of like mine better being wired "wrong".

Tapping in before the stock back up light switch would still just give you two power sources on the new switch. Battery and ign. Being in reverse wouldn't come into play which is why you want to tap in after the switch.

Which ground wire is melting? I found Alan's diagram easier to use for relays in general compared to others because he labeled the trigger and load. Seems it makes it easier to keep on track thinking in those terms. Ended up printing that out and then labeling the relay terminals with their numbers just to keep myself straight.
 

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Discussion Starter · #7 ·
I grounded both the relay and the switch on the panel that the e-brake release is bolted to. I had tested the ground before hand to make sure it was a goo ground and it worked. I didnt try to switch the wires on the switch terminals itself yet to see if it was possibly labeled wrong. I'm hoping that the reason to cause this is the fact that i used the fuse for the factory reverse lights under the hood instead of the wire at the tail lights. Thanks for the info and posting so fast. I hope I can figure out the problem tomorrow. My hands got to damn cold to finish tonight. Once its squared away tomorrow (hopefully) I'll post up what the problem was. Thanks again guys

Nick
 

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Nick,

Why did you ground the switch? The only switch I know of that requires grounding is a SPST with an internal indicator light.
 

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OK, had a hunch. The switch shouldn't be grounded. Using the diagram c.schulz posted can be confusing since the center terminal on the switch "appears" to be grounded. It shouldn't be. That path to ground only comes into play if you're using an indicator lamp which, as stated further in that post, would be a better indicator if wired on the load side of the relay anyway. Alan's diagram is really straight forward. http://www.snowplowing-contractors.com/alan_reverse_lights.html

You really need to tap into the existing reverse wiring after the stock switch. Tracing the wires back inside the cab and making the connection so that it's not exposed to the elements is best. You could tap in using the wiring by the stock reverse lights and run the wire back to the new switch in the cab but that's a lot of unnecessary work and wire.

Seems when I need to do wiring and its cold, dark, wet, I'm crunched for time or any combination that's when the gremlins show up. What I've found that works best for me is to stop, disconnect everything and start over. I may not disconnect splices but I make absolutely sure that I've made the splice where I want it to be. Then I don't reconnect anything until I've traced it back to the source. I've "checked" my work ten times and still not had it right. Disconnected everything then reconnected and it worked. Magic? Probably not, just had something wrong in the first place and couldn't "see" it.....Geoff
 

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Discussion Starter · #10 ·
Alan said:
Nick,

Why did you ground the switch? The only switch I know of that requires grounding is a SPST with an internal indicator light.
Hmm, so then I run the off position wire coming from the switch to the #30 prong on the relay? Now I'm a bit confused.

Nick
 

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The Schultz drawing is a little easier to follow as it has terminal numbers, which mine lacks. If you're NOT using an indicator lamp then you eliminate that leg going through the lamp to ground. If you attach a ground to the center terminal of your switch you have a dead short and bad things will come to you. One thing to remember, if you have a power source in the current low without some sort of load and ou take it to ground you have a short circuit,, no matter what. It is the load that sets the current flow, in the case of the Schultz drawing, the load it the indicator lamp. That circuit wil draw only current enough to light the lamp. Without the lamp but with a ground connection current will not bother going through the relay coil because the easiest path is through the ground connection. The current able to pass that is, for all practical purposes, infinite for a short period of time and the wires in that circuit will quickly become fire starters.

Always, no matter what else, install a fuse between the source of power and the switch.
 

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The picture of Alan's wire diagram is a little incorrect,as the terminals are wrong on the relay.It's just the way the diagram is drawn.On a normal relay,the trigger terminals are directly across from each other,as are the power feed and load terminals.

Relay terminals are:

30 - power in from fused source.This will power your load.
85 - trigger 1
86 - trigger 2
87 - normally open,output to load is closed when relay engaged,sometimes a relay will have two of these
87a output to load that is normally closed,opens when relay engaged.Commonly used to "switch" something,like truck headlights to plow lights.

So you need a SPDT switch.That switch will have 3 terminals.

Wire your relay as follows.Heavy fused lead to the 30 terminal on the relay.Terminal 87 will go out to your reverse lights.Ground terminal 86.Terminal 85 will run to the center terminal on the switch.

One of the outer terminals on the switch will go to your reverse light feed from the stock truck reverse lights.

The other outer switch terminal goes to switched ignition power,so you cannot leave the reverse lights on when the truck is shut off.If you do want to have them on with the key off,then wire it to any battery feed.I wouldn't recommend it,as you may leave them on and kill the battery.If you do wire it this way,wire a bright indicator lamp so you know they are one.It would be wired between the center switch terminal and ground.

The switch is not grounded anywhere.It sounds like this may be your problem.If it's melting your ground,then obviously you have a direct short to ground.



.
 

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Sorry Nick, and Alan too. Confused things since I apparently bought the wrong switch. I preferred Alan's diagram because it's more descriptive of what the relay does. I printed it then numbered the relay terminals and have used it a couple of times now.
 

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Discussion Starter · #15 ·
wyldman said:
The picture of Alan's wire diagram is a little incorrect,as the terminals are wrong on the relay.It's just the way the diagram is drawn.On a normal relay,the trigger terminals are directly across from each other,as are the power feed and load terminals.

Relay terminals are:

30 - power in from fused source.This will power your load.
85 - trigger 1
86 - trigger 2
87 - normally open,output to load is closed when relay engaged,sometimes a relay will have two of these
87a output to load that is normally closed,opens when relay engaged.Commonly used to "switch" something,like truck headlights to plow lights.

So you need a SPDT switch.That switch will have 3 terminals.

Wire your relay as follows.Heavy fused lead to the 30 terminal on the relay.Terminal 87 will go out to your reverse lights.Ground terminal 86.Terminal 85 will run to the center terminal on the switch.

One of the outer terminals on the switch will go to your reverse light feed from the stock truck reverse lights.

The other outer switch terminal goes to switched ignition power,so you cannot leave the reverse lights on when the truck is shut off.If you do want to have them on with the key off,then wire it to any battery feed.I wouldn't recommend it,as you may leave them on and kill the battery.If you do wire it this way,wire a bright indicator lamp so you know they are one.It would be wired between the center switch terminal and ground.

The switch is not grounded anywhere.It sounds like this may be your problem.If it's melting your ground,then obviously you have a direct short to ground.



.

Ok guys good news. I worked out the problems and used Wyldmans (thank you) directions and everything is good to go. I just wanted to thank you guys for taking the time to help me out and post up some pointers and directions. My next problem is I may be buying a 2007 2500HD with the Duramax and will have to swap not only these lights but my strobe lights, plow and frame/wiring, and the wheels (H2 wheels and tires). This should be an interesting weekend. Thanks again guys

Nick
 

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K, standard automotive relay - note the terminal numbers:
Connect 85 to the main beam on your car (via a dash switch if you want),
Connect 86 to ground.
Connect 30 to battery +ve via a 20A fuse (at the battery end).
Connect 87 to your spot lanterns (with the -ve terminal on the spots to battery negative)

Use 4mm wire from the battery to the relay, and from the relay to your spots (and for the ground wire.

You can use 1mm wire for the "signal" wire from the main beam via your switch to the relay.

Use good quality crimp connectors (DO NOT SOLDER!) with a proper ratchet crimp tool.
 

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Hey guys, although I'm new to post I have been going thru the threads for a long while. Anyway, I bought some 55 watt "fog" lights to use for my reverse lights while I'm plowing. I have a 2002 Chevrolet 2500HD 6.0 :mad: with a meyer 7 1/2 classic on it. My problem is this, I wired up the lights using a 3 way 25 amp switch so I could leave the lights on or have them go on when in reverse. I also used a 30 amp relay from radio shack and all 12 guage wire. I grounded the lights by the mounting bracket. I used both of these diagrams for wiring it. 3 position reverse lights and Alan's Reverse Light Wiring Diagram - Snowplowing-Contractors.com . I then started the truck only to see the lights go on while the switch is in the off position. I then turned the switch to where it would have the lights on all the time and it burnt the ground wire within seconds. I went over the wiring about 10 times and it was correct each of the times. I am lost as to why this would happen. Is it possible the relay is no good? Any help or tips would be greatly appreciated. Thanks guys and sorry for the long post

Nick
You have bigger issues than the lights, a 7.5’ Meyers on a 3/4 ton? 🤣 I have an 8’ Fisher SS on a 2022 Silverado 1500 plow prep package and it handles any snow that comes in front of it. Throw an 8’ at least on a 3/4 ton 6 liter but not another meyers ! The truck will handle it with ease and do a job quicker, good luck with those lights!
 

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You have bigger issues than the lights, a 7.5’ Meyers on a 3/4 ton? 🤣 I have an 8’ Fisher SS on a 2022 Silverado 1500 plow prep package and it handles any snow that comes in front of it. Throw an 8’ at least on a 3/4 ton 6 liter but not another meyers ! The truck will handle it with ease and do a job quicker, good luck with those lights!
Almostfinished is probably FullyFinished by now being its been 15 years
 
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