rimcanyon
Diamond
- Joined
- Sep 28, 2002
- Location
- Salinas, CA USA
Since some of the EE's hang out here, I hope you can help me with a simple problem. I bought a Harbor Freight LED hitch light for my Ford T350, which has a factory hitch and trailer wiring. The Ford computer doesn't much like the HF hitch light, which uses the 4-pin adapter and connects to pins 1 and 4. Since pin 3 is not loaded, the computer thinks a trailer is connected and it has a burned out bulb on the left side, so it blinks the left turn signals at double rate. That is the problem I want to fix.
I think that if I rewire the HF hitch light with two diodes, so that there is one diode from pin 3 to the light's hot lead, and another from pin 4 to the light's hot lead, then the light should work as follows: the hitch light will be on whenever either or both taillights are on. i.e. if the vehicle is turning right or left the hitch light will flash, and it will be on steady if the brakes are on or the taillights are on, and the computer will be happy, so both sides will flash at the same rate. Do I also need to add a resistor between each diode and the light's hot lead, so that the circuit is slightly more loaded?
Assuming the above is correct, is there any simple way to get the hitch light to also blink when the turn signal is on and the taillights are on? That is what it does currently when turning right with the lights on, but I think that feature will disappear once pin 3 is added to the circuit, as described above.
-Dave
I think that if I rewire the HF hitch light with two diodes, so that there is one diode from pin 3 to the light's hot lead, and another from pin 4 to the light's hot lead, then the light should work as follows: the hitch light will be on whenever either or both taillights are on. i.e. if the vehicle is turning right or left the hitch light will flash, and it will be on steady if the brakes are on or the taillights are on, and the computer will be happy, so both sides will flash at the same rate. Do I also need to add a resistor between each diode and the light's hot lead, so that the circuit is slightly more loaded?
Assuming the above is correct, is there any simple way to get the hitch light to also blink when the turn signal is on and the taillights are on? That is what it does currently when turning right with the lights on, but I think that feature will disappear once pin 3 is added to the circuit, as described above.
-Dave