Troubleshooting Curt Custom Fit Vehicle Wiring Harness # C55486 in 1998 Toyota RAV4

Question:

Hi, after reading the instructuins and installing this, everything worked well for 5 minute, i decided to drive the car around. The car started, but the speedomete, odometer, ac, radio, wiper stopped working. Checked all the fuses from the fusibles to the fuses on the driver and passenger sides, still not working. I reversed the whole process and removed the curt product. The car started right away but the dash, ac, radio, wiper, interior lights are till not working. I even changed the alternator... Still the same. What do i do next? i really need your help. Thanks you.

asked by: Victor

Expert Reply:

A 4-pole trailer wiring harness like Curt plug-and-play # C55486 interacts with a vehicle's electronics only in three circuits: brake lights, running lights and turn signals. What the harness does is take the separate stop and turn signals from the car and combine them for the trailer, which uses the same light for stop and turn functions.

A wiring harness has no direct interaction with other vehicle systems like wipers, radio and air conditioning. It is possible that a damaged harness could cause a fuse to blow in one of the involved circuits but since no fuses were bad in your RAV4 it sounds like just a coincidence that these vehicle systems failed when the harness was plugged in.

In some cars multiple circuits might share the same fuse. The radio and interior lights on your car are served by engine compartment fuse 9; various lights are on fuse 20 on the driver's side fuse panel and the air conditioning is handled by fuse position 28. Re-check these fuses to ensure they have not blown.

It is likely that your speedometer is mechanical, meaning cable-operated. If so, this could not possibly be affected by the harness, which I confirmed with my technical contact at Curt.

expert reply by: Adam R