Aux Back Up Light Problem!

[1 ALC]

I'm trying to wire my aux back up lights (actually cheap fog lamps) and it keeps blowing fuses. I grounded to light to the bumper - it blew the fuse. Tried tying into the harness from the rear lights - didn't blow the fuse, but got hot - so I unplugged it before it blew the fuse!



Hooked a 'jumper box' directly to the light and it worked fine, with the hot and ground from the box straight to the light.



I wouldn't think I would have to run a ground all the way from the battery, just for a good ground! I do think its a ground problem.







-Thanks. .

 

[GSchlegel]

1 ALC,



I mounted a 30 amp relay under the back of the truck. Sealed it with silicone. I ran a fused hot wire direct from one of the batteries to the relay and picked up the signal from one of the backup lights. Others have used the hot wire in the 7 prong RV plug for power. I use it to power 2 tractor flood lights and a very loud backup alarm. I grounded to the frame. Hope this helps.



Gene

 

[Thomas]

It sounds to me as though you have two wires? coming from your fog lights and that one of them is grounded, and you're running power to ground. Pull the bulb out the lamp and check the resistance of each lead to the mount of the fog light.

 

[Forrest Nearing]

what type of relay are you running? it doesn't SOUND like a ground problem to me...



Forrest

 

[rich m]

yer treatin' the factory b/u wiring like HD....it ain't

Do like one of the other posts said.



Get a relay that'll easily carry what the bigger lites draw

(the relay will be rated by AMPS and the lites will be rated by WATTS--- for every 100 WATTS of demand you need to be able to deliver about 9 AMPS of current. )



The relay will have, depending on design, either 3 or 4 leads.

Regardless of design, there will be a Heavy-in and a Heavy-out. You need a dedicated length of 10G copper (just because Dodge didn't run one back there) line from the battery (fused at about 20A, for safety) all the way to the rear work area. Terminate the battery-line at the Heavy-in. Run your Heavy-out lines over to your big bulbs.



Now, you're ready to wire the "trip" portion of the relay. Just run a tap-line (parallel splice) from the "hot" side of one factory backup light wiring down to the 'switch' terminal of the relay. If your relay has only the 3 terminals, you're done, except for a test.



The test consists, simply, of "ignition ON" (no need to start engine at all) -----gear-shift lever into "REVERSE"

If you've wired it all correct, your factory b/u lamps will light, just like always, but in addition, you'll hear a "click" or "clunk" caused by the tripping of the relay, and your new big bulbs will lite up, too.



If there's a 4th terminal on your relay, it SHOULD be a "ground", and can be routed right under its own mounting screw. If it's got only 3 terminals, its PROBABLY self-grounding.



Ground the new bulbs return wire directly to their own mounting screws.





As for the theory that you have a grounding problem, no. You have an overload problem.



For the relay, the one guy used a 30-A one... . I, being the overkill nut that I am, used a 4-terminal solenoid that was intended for a Ford starter. (makes a big "audible" when it engages and disengages) I mounted it behind and above the LR fenderwell where it would be out of harm's way, unless I go somewhere and totally submerge the rear axle. .

 

[1 ALC]

Thanks, everyone!!

It was a combination of problems. I didn't realize I needed a relay! Also the lights didn't need to be grounded. I still don't know why, but they started working when I unplugged the ground wires, and ran the '+' to the lights!



Now, I can back up to the trailer, put the Ram in 'Park' and hit my lighted switch, and see what's going on!