Express 2004, 2500. 6LV8. 359,000m

Left turn signal is intermittent. Sometimes works, sometimes flashes2-3 times, then quits. Mostly not at all. Right turn is fine. Samr thing happens with the emrgency flasher. Any ideas where to start? All lamps do flash when its working.

 

1.) Loose Flasher / Fuses. Check all that apply.
2.) Loose, Dirty, Corroded Connections. Check all that apply.
3.) Near Broken / Loose Wire. Inspect.

 

You can probably rule out the flasher relays. They are separate relays (T/S & 4 way), so unless both are bad, it's not the issue. I'd ask if when it happens, are they are lit or go dark. Usually, when a bulb or socket go bad, the unaffected bulbs stay lit, but don't flash. It would have to be something that both T/S and 4 ways share, so check if they share a fuse. The rear socket harness is notorious for failure. It's a harness that plugs in at the tail light. If your van is a cargo van, you should be able to see it on the inside. I'd assume there is one for the front as well,but I've never been in there.