There's More Than One Way to Melt a Headlight Harness
by Ryan Kooiman
In the middle of what you thought was a routine headlight bulb replacement, have you ever unplugged the bulb and found a melted harness (AKA connector)? Here are the causes, and how you fix the problem.
This scenario is something that technicians regularly encounter, whether they’re working on an Acura, BMW, Chevy, Ford, VW or any make or model in between. Most of the time, the issue is caused by the OE wire gauge, which is too small (typically 20 gauge) to handle the current drawn by the headlight bulbs. In other cases, the issue is the result of loose terminal connections, which can cause resistance in the circuit and lead to overheating. Still, in other instances, the vehicle may have an “upgraded” bulb, which on the application being used creates more heat than the original. Each of these scenarios can cause the original to melt and fail.
In the past, the only solution available to technicians was replacing the connector with one similar to the failed part. This isn’t the most satisfying repair, because the technician must send the vehicle out the door and hope that the repair lasts as long as the original connector.
A Solution That Prevents Melting
Understanding technicians’ frustrations, the team at TechSmart worked to find a better solution for the melted headlight wiring harness problem. The result was a line of headlight wiring harnesses, all featuring high-temp connectors that can withstand extreme heat. Here are a few other features:
- 14-gauge wire for better conductivity
- “Plug & play” function allows you to plug harness between the factory harness and new bulb
- If the original connector is melted, the harness can be used as a pigtail
- Coverage for the following high-temp bulbs: H1, H3, H4, H7, H11, 9004, 9005, 9006, 9006XS and 9007
If you’re replacing a bulb and the original harness is not yet damaged, it’s recommended that you install one of these harnesses to prevent a future problem.
Ryan Kooiman is the Director of Training at Standard Motor Products. He leads SMP's award-winning PTS training program and can be seen on Standard's YouTube channel. Ryan has ASE Master L1, L2, and L3 Certifications, and has had articles published in over 30 periodicals.