Hyundai headlights dim

Excessive resistance in high amperage circuits can cause an issue where Hyundai headlights dim or Hyundai blower motor slows down, or Hyundai radio turns off and on. The high resistance can also cause the ABS light to come on and set multiple trouble codes like; C2402, C1102, C1616 & C1611. The high resistance can also cause the PCM to shut down the alternator, making you think it’s bad.

Service Bulletin addresses problem Hyundai headlights dim

Hyundai service bulletin #08-BE-004 describes the headlight dimming, blower slowing down, and radio turns off and on problem. Hyundai engineers have narrowed the cause down to excessive resistance in high amperage circuits and have issued the service bulletin to describe how to find those areas of high resistance.

You’re need a digital multimeter

You don’t have to spend a lot of money on a meter.

Buy a digital multimeter at Walmart for around $10

Find one here or buy one at a local home center store. Set the meter to the lowest setting for DC volts. Then start the vehicle and turn on the headlights (low and high beam), A/C, and set blower to MAX speed. The test voltage drops at these locations:

1) Start by checking the voltage drop between the positive battery cable and the main power lead to the underhood fuse box (remove the cover and you’ll see the lead). Place on lead of you meter on the positive battery post and the other on the stud securing the positive lead at the underhood fuse box. The maximum reading allowed is 0.20v.

2) Connect one meter lead to the negative battery post and the other lead to where the negative battery cable connects to the inner fender. Again, maximum voltage drop is 0.20v)

3) Connect one meter lead to the negative battery post and the other lead to every ground location under the hood—wherever you see a cable screwed into the fender, firewall, or engine. The maximum reading allowed is 0.20v. Repeat on all transmission and engine ground straps.

If any connection shows more than 0.20v., the connection must be disassembled and cleaned. Turn off the engine and disconnect the battery terminals. Remove the affected power wire or ground and clean off any sign of corrosion. If the threads are corroded, chase them with a tap. Clean the ring terminal at the end of the power wire or ground strap. Then apply a light coating of dielectric grease to the newly cleaned bare metal sections and re-assemble.

© 2016 Rick Muscoplat