intermittent turn signals

The Freightliner FLDs use a relay for a flasher that is controlled by the light bar just above the speedo and tach. First, check or replace the flasher relay in the electrical console under the center dash, and check for any shorts that may be occurring.

If the problem continues to exist, then you need to see if the relay continues engaging and disengaging. It'll be 'clicking' but you won't have any lights operating. If that is the case, there will likely be a short or a faulty circuit breaker powering the turn signals. Freightliner likes to use Type II circuit breakers that are only reset by removing the power or load. They have a heating element inside that keeps the bimetal conductor thrown. There is enough power going through that heating element to operate the relay, but not enough to power the lights. However, due to the on and off nature of the lightbar signal, the heating element slowly cools and the flashers will come back on. You'll think the circuit beaker is ok, when it is actually thrown.

If you have no shorts and the circuit breaker is fine, then you likely have a bad VIGIL lightbar. They are not cheap, so the simple solution is to remove the relay, and install a regular flasher. It will fit, but you have to make sure it is installed correctly. If it is a lightbar issue, let me know and I will look to see what two terminals (of the four that are used in the connector) you need to install the flasher into. I use a heavy duty electronic flasher (Velvac P/N: 091212) on my retrofits. It's square and fits perfectly in the original relay location.

Hope this helps.

 

Hold on here. Before you go tearing the truck apart check the simple stuff like making sure you don't have a loose connection or a rusty ground connection.