Dash Lights On 2011 Toyota Highlander Appear with Trailer Connected To Solar Power

Updated 05/28/2019 | Published 05/24/2019

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Question:

Hello, I have a 2011 Toyota highlander with a new break control system that was installed in local Toyota dealer. I just bought an used Jayco 16inch hybrid RV/trailer that has a permanent solar roof panel and a EWC-30 solar charge controller that was working without any issue according to the previous owner. My problem is that when I hook up the trailer to my highlander, the truck front panel shows a few emergency conditions pop up the air bag, tire pressure, ABS signal and I can not turn off the truck. Actually, the system does not allow me even drive. I hooked up the truck to another trailer no solar panel and everything in the truck was fine. No problem at all. Then I hooked back the truck to my trailer but before I removed the fuse from the solar panel and everything was OK. Any suggestion or possible way to fix this? Thanks in advance

asked by: Luis P

Expert Reply:

That is certainly an odd or rather uncommon issue that you described. The only thing I can really think of would be power back feeding on the trailer battery charge wire. However, this would only really cause an issue if this wire was not ran to the positive terminal on the tow vehicle's battery. Therefore, this would be the first thing I check (where the trailer battery charge wire is ran to on the vehicle). For example, if the trailer battery charge wire from the 7-way was ran to a fused circuit on the tow vehicle that could then very well be the cause of your issue. If it is then you will need to remove this and run that wire directly to the vehicle battery with part # 10-1-1 and part # 9510.

Please let me know once you can confirm where the trailer battery charge wire is ran.

expert reply by: Conner L