Troubleshooting Lights Dimming When Brakes are Applied with Trailer Connected 2012 Toyota Tacoma

Updated 01/28/2013 | Published 01/25/2013

Question:

when i have trailer hooked up and driving down the road and i come to a stoplight and have to apply brakes the lights on dash dims but when the trailer is not hooked up to truck it does not do this,i have a 2013 toyota tacoma base model..

asked by: Scott S

Expert Reply:

There are a couple issues you may be having. You may have a bad ground or short on your trailer wiring and when you hit the brakes the short causes an excessive drain on your vehicle battery and your lights dim. If you see the voltmeter on your dash dive when this happens then you know this is happening.

You could have a weak battery or alternator, around here you can have those things tested at local car part stores.

You may also just have too many lights on your trailer and there is an excessive load on the vehicle. Due to how new your vehicle is this seems unlikely.

You should check for shorts or exposed wire on the trailer wiring and fix as necessary.

expert reply by: Jameson C