Originally Posted by Go4Broke
hello guys, Iím just entering the skoolie community and im almost done with my build. my 2004 Thomas Freightliner FS65 has this weird issue with the turn signals where all flashers will flash when I try to indicate I am turning left or right. the only place where the lights flash left or right respectively is in the dash. the lights dont seem to blink excessively fast or slow.
any help would be appreciated
Sounds to me like you have wires melted together somewhere after the flasher, from the firewall out to the front signals and rear signal wires.
Start at the signal lights, front and follow them back for left and right. They may have been resting near exhaust, turbo or rad and melted the insulation connecting both sides to together which seems to be the condition you describe.
If you have an ohmeter handy, set it on ohms. Test from the power wire on the left signal to the power wire on the right signal and check if they are indeed connected. Do this with no power on, but move the turn signal switch from left to off and right and compare results.
Your flasher seems to be working when the dash indicators work properly in my mind.