What are the Correct Replacement Bulbs for Optronics Trailer Lights # ST6RB and # ST7RB

Question:

I have optronics trailer lights with one main bulb and a side blinker bulb that pushes into the connector, what bulbs do I replace these with ? I used the 1157 and 168 and my blinkers will not work. Are these the correct bulbs?

asked by: Rich R

Expert Reply:

It looks like you have Optronics Lights # ST6RB and # ST7RB. For either of these lights, the correct replacement bulb will be # A1157B that you have referenced and # 30-90-194 for the side light.

Trailer lights are a 2-wire system. This means that they have combined stop and turn signals on the same bulb. If the lights do not blink with the turn signals, you may need to change the running light wire with the stop/turn signal wires. Use a circuit tester like # PTW2993 to test the trailer wires to determine with is running lights and which is stop/turn. If the wires were switched the stop/turn lights would be dimmer than the running lights.

Also make sure that the lights are grounded to a clean and corrosion free bare metal surface. A bad ground at the lights can cause a malfunction. Also check the vehicle and trailer side connectors for any dirt and corrosion.

expert reply by: Michael H