Turn Signal / Warning Light Issue

[Duckman]

All of a sudden having issues with the turnsignals on my Series III lightweight. When I attempt to switch on turn signal (either Left or Right) they do not come on and the green turn signal indicator as well as the yellow "trailer warning" lights on the dash come on and stay on.

Never had this happen before. Also have no earthly idea what the "trailer warning" light is even supposed to tell me.

Any ideas?

Thanks.
Andy

[mrdoiron]

All of a sudden having issues with the turnsignals on my Series III lightweight. When I attempt to switch on turn signal (either Left or Right) they do not come on and the green turn signal indicator as well as the yellow "trailer warning" lights on the dash come on and stay on.

Never had this happen before. Also have no earthly idea what the "trailer warning" light is even supposed to tell me.

Any ideas?

Thanks.
Andy

Not sure on the Lightweight, might check all the contact connections for anything come loose - and have you tried swapping a new signal relay, they're cheap..should be right behind the dash plate on the firewall.

[Alk-3]

Something similar happened to me and turned out to be the trailer connection wiring harness malfunctioning. It was a head scratcher for quite a while before I found it.

[disco2hse]

If you have a broken circuit, like a blown bulb, the light flashes once then go off. So if your s are staying on I would tend think there is a short somewhere. Maybe a wire has touched, dirt has shorted it, insulation has melted off and created a short... (that last happened on my rear indicators and tail lights and was right by the fuel filler tube).

[jac04]

Check the turn signal/hazard flasher unit under the hood. Tap on it a few times. Could be a sticky contact. On my Lightweight, I found a bad connection inside the unit and was able to re-solder it. However, every once in a while my signals won't work. I turn on the hazard flashers, then turn them off, and everything works fine again. Don't know why. One day I'll replace the signal unit.

[siiirhd88]

I don't know what a lightweight uses for a turn signal flasher unit, but the typical older non-electronic flasher units use a bi-metal strip to make-and -break the flasher circuit. The bi-metal strip carries the current flow from one flasher contact to the other when closed, and is made from very thin strips of different types of metal attached along their length (like one side copper, the other side tin). As the current flows thru the bi-metal strip to the lamp filiments, the strip heats up causing the copper side to expand differently than the tin side. This differential expansion makes the strip curve, pulling the end away from the breaking contact which stops the current flow (and the lamps go out). As the strip cools, it straightens out and again makes contact..... repeat.

If there is a broken bulb or wrong type of bulb, or an open wire or corroded connection there might not be enough current flow the make the strip flex and the lamps won't flash. If there is a short to ground in the wires between the flasher and bulbs the strip heats quickly and the lamps can flash very rapidly.

The electronic flashers are basically a timer that open and close the circuit regardless of load.

Most circuits have constant power run to the flasher unit (green wire) and from the flasher unit to the turn signal switch. The turn signal switch closes contacts to complete the circuit to the selected lamps. When the emergency flasher is actuated, most emergency flasher switches isolate the power to the normal turn signal flasher.

Bob

[jac04]

I don't know what a lightweight uses for a turn signal flasher unit, but the typical older non-electronic flasher units use a bi-metal strip to make-and -break the flasher circuit.
The Lightweight uses an electronic flasher unit with a relay, not the bi-metal type unit.

[Duckman]

Thanks everyone, now I have some good ideas where to begin the trouble shooting.

Andy

[siii8873]

I struggled with a turn signal problem on my exmod. It would work correctly and then the trailer warning light would start flashing which always was a precurser to the signals stopping working. The problem ended up being a bad connection on the terminal block. Have not had an issue since repairing the connections.