2002 hazard light issues

2002 Volvo? That’s a gen 1. There should be a plug on the passenger side, between the cab and 5th wheel, inside the frame rail [but closer to the cab]. Look inside the frame rail there below the cab, there’s a plug which is an extension of 12v, turn signals and etc. I’m not sure if it passes’ through the hazard signals, but it does pass through 12v running lights and what not.

Unplug that plug (it’s a plug and clip style plug with about 4 wires on both ends) and turn on/ run your hazard lights. Test for voltage on the truck side of that plug. You’ll have to test each of the four or so leads on the plug to find out what is what. BUT, if you catch a blinking (hazard light style flash) 12v signal on the truck side then u know the issue is after the plug and on towards the rear of the tractor. Could be a shorted wire grounding out, touching metal somewhere etc

 

check hazard switch connections in the dash, everything goes seperate also there is a seperate fuse.

 

Check Fuses 64-65-66-67 first

 

Had the same issue on my 03. It was the wire from the hazard switch to the brake light relay that was broken.