I am trying to install cab marker lights on my truck and can't find a hot wire when marker and headlights are on. Is there a fuse for the headlights because there is none in my fuse box under the steering column. I've been probing different wires to try and find one to tap into.

 

The the fuse will be hot all all times. It gets power to the headlights when you turn the switch on. Tap into a running light wire and run a wire to the switch side of a relay, then run your lights to the relay. That way you will not be putting much more strain on your headlight switch. Now would be a good time to wire in relays for your headlights also to take some strain from the headlight switch.

 

Okay I just went and run the hot wire from the marker lights through the firewall to under the hood and hooked into a wire running to the drivers side front marker light. I hope this doesn't cause too much pull on that wire. Thanks for the info about the relays, yeah I should have done something like that so I'm not putting so much pull on the headlight switch.

 

The relays usually make your headlights brighter, also.