Hi folks. I have a '74 Ford 800 (391FT gas) that puffed a little smoke from under the dash somewhere last week. I then had no turn signals or brake lights. The 4-ways work in the front, but only one side in the rear. Unable to find a short anywhere in the rear or along the truck frame we have decided to check the TURN SIGNAL FLASHER - but can't find it. we have located the 4-way flasher but not the turn signal unit. The year of the truck makes it difficult to find wiring diagrams. Thinking that the flasher unit may be the culprit we'd like to locate it. Thanks folks!
It should be behind ignition key to the left of the clutch pedal. Mine just hangs there. Your short should be there too. The brake lights and the blinkers use the same wire on a trailer plug. Is the truck wired with a trailer plug? That has has happened to me before.
no trailer D9.. although this is a converted road tractor from 1974 so I guess nothing will surprise eh? in the area you described I have 2 boxes (look like relays) mounted up behind the SC to the left. One of these is the 4-way flasher - you can feel the 'click' when it flashes.. We aren't sure what the other box is. My mechanic doesn't seem to think it's the TS flasher, but we have searched high and low looking for the TS unit to no avail. We have narrowed the location of the short down to the dash area left of the fuse box.. we have 'cleared' the wiring from the taillights, up the frame, into the cab and past the heater box. So at this point we have it limited to the area with the most wiring... LOL Thanks for the input!
I think that is it, try swapping them. Look for a bad connection or a splice someone has put in in the past.