Trailer light malfunction error message

[MattG]

So, I added two 1N5408 (3 Amp, 1000V) diodes to the two tail light cables in the trailer wiring loom (joining them together downstream) before I then completely rewired the 7 pin flat plug with wire colours that suit the Australian standard. Unfortunately this didn’t initially fix the problem. I was still getting the “Trailer light malfunction” error/warning. So I then I added in the “jumper box” I made (that contains five 21W Narva LED Load Resistors across the 5 light circuits) and hey presto, the error message/warning has disappeared! I can easily mount the jumper box on the drawbar of our camper trailer and use this with any other trailer with LED lights. Phew! Fingers crossed it keeps the Grenadier happy!

 

[Rainydaytoast]

So, I added two 1N5408 (3 Amp, 1000V) diodes to the two tail light cables in the trailer wiring loom (joining them together downstream) before I then completely rewired the 7 pin flat plug with wire colours that suit the Australian standard. Unfortunately this didn’t initially fix the problem. I was still getting the “Trailer light malfunction” error/warning. So I then I added in the “jumper box” I made (that contains five 21W Narva LED Load Resistors across the 5 light circuits) and hey presto, the error message/warning has disappeared! I can easily mount the jumper box on the drawbar of our camper trailer and use this with any other trailer with LED lights. Phew! Fingers crossed it keeps the Grenadier happy!

Hey.

I just got a trailer that does similar issues to this. Turn signal plays up etc. I think i need what you've done here. Looking at your tidy work i can't quite see what you did with the negative wire from the resistors. If my understanding is correct i need 1 resistor per circuit and its hooked to that circuits positive and negative. I see your negatives are in parallel. I assume they connect to the main negative?

Thanks

 

[Rainydaytoast]

I am not an electrician or an artist but this is how i see your set up.

 

[MattG]

I am not an electrician or an artist but this is how i see your set up.

View attachment 7857405

Yep, the resistors are all connected in parallel with the trailer wires from the Tail lights, Stop lights, Left and Right Indicators and Reverse lights. The trailer wires each connect to one terminal of a 21W resistor AND to the corresponding wires exiting the setup heading for the vehicle. The other end of each of the 21W resistors is connected to ground along with the ground wire from the trailer and the ground wire heading off to the vehicle. There is no resistor on the ground wire nor on the electric brake wire. I have since simplified my setup (having worked out that I only need resistors to the tail and reverse lights). The attached photo probably shows the setup a little better. Hope that helps?

 

[Rainydaytoast]

Yep, the resistors are all connected in parallel with the trailer wires from the Tail lights, Stop lights, Left and Right Indicators and Reverse lights. The trailer wires each connect to one terminal of a 21W resistor AND to the corresponding wires exiting the setup heading for the vehicle. The other end of each of the 21W resistors is connected to ground along with the ground wire from the trailer and the ground wire heading off to the vehicle. There is no resistor on the ground wire nor on the electric brake wire. I have since simplified my setup (having worked out that I only need resistors to the tail and reverse lights). The attached photo probably shows the setup a little better. Hope that helps?

Thats brilliant. Saved me buying a bunch of resistors I dont need!

Thank you