Jeep Wrangler Forum - Reply to Topic
Jeep Wrangler Forum

Go Back   Jeep Wrangler Forum > TJ Jeep Wrangler Forum > TJ Tech Forum > Fog Light Trouble

Join Wrangler Forum Today

Thread: Fog Light Trouble Reply to Thread
Post Icons
You may choose an icon for your message from the following list:

Register Now

In order to be able to post messages on the Jeep Wrangler Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Additional Options
Miscellaneous Options

Topic Review (Newest First)
01-21-2010 08:44 AM
Kilroy Long lines dissapate some of the energy going to the load. If the line is too long, or the wires too small, the lights will not be as bright. If the wires are way too small, they will get hot and could cause a fire. This is true for AC and DC current.

Household wiring is 10x the automotive 12V, so it takes 10x less current to produce the same power.
01-21-2010 08:18 AM
Beachcomber Much more, that's why your home and the country uses AC voltage. If we had to wire for DC our homes would have wires the size of your plumbing pipes.
01-20-2010 08:31 PM
Jerry Bransford
Originally Posted by Beachcomber View Post
DC voltage has a lot of line loss.
More than AC voltage line loss?
01-20-2010 08:27 PM
Beachcomber Your calculation is correct but you need to take into consideration line loss. The longer the distance the more loss and the current draw becomes larger. DC voltage has a lot of line loss. When you use a relay you should place the relay as close to the battery and as close to the lights as possible to keep the loss to a minimum.
01-20-2010 08:01 PM
Kilroy Just do not rapid cycle the switch. This is also true for relays.
01-20-2010 07:30 PM
s3nt3nc3d i = w/v

i = amp draw
w = watts
v = voltage

So given that formula...

i = 110 (2 55w fog lights--estimated) / 12 volts

i = 9.2 amps

Am I correct in that calculation aside from estimating the fog light wattage?

So a switch rated at 15+ amps should be able to carry that load, wouldn't it? ...possibly up to a 30amp switch if they are high powered bulbs.
01-20-2010 07:13 PM
Kilroy Use a relay if the lights or other load draws more amps than 0.75x the switch Max. Amps. And make sure the wires are big enough for the amps.
01-20-2010 05:48 PM
Relay Wiring

You should allways wire extra lights and stuff using relays. Here is how they should be wired.

Tis wall save your switches and the harnesses from frying.
01-20-2010 05:36 PM
Kodysteeler43 idk what a relay is but there is a wire hooked to the battery and then pops out in the steering column with a positive and negative wire.
01-20-2010 08:53 AM
Originally Posted by Beachcomber View Post
Did you use a relay or did you wire them directly to the switch? If you wired directly to the switch you could have fried the switch.
Sounds to me like your Pap didn't use a relay.
01-19-2010 07:28 PM
Beachcomber Did you use a relay or did you wire them directly to the switch? If you wired directly to the switch you could have fried the switch.
01-19-2010 07:06 PM
Fog Light Trouble

I have two fog lights on my bumper. My pap hooked them up. They worker for about two weeks then suddenly stopped. The left light turns on when the switched is somewhere in the middle and the right never even flickers. Is this the wiring or the switch?

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

All times are GMT -5. The time now is 05:04 PM.

Jeep®, Wrangler, Liberty, Wagoneer, Cherokee, and Grand Cherokee are copyrighted and trademarked to Chrysler Motors LLC. is not in any way associated with the Chrysler Motors LLC