If you’re in the market for a fog relay—particularly the now no longer available (NLA) part number 61311374631—here’s a crucial piece of information you should know before buying any replacement.

The stock relay for this part comes with a diode, while most available replacements do not. This seemingly minor difference can cause some unexpected and frustrating issues with your vehicle’s lighting system.

Why Does the Diode Matter?

Without the diode in the replacement relay, pressing the fog light button while the main light switch is off will result in the low beams turning on. You might also notice the low beams dimming, accompanied by erratic behavior from the low beam relay. In short, the lighting system gets confused and doesn’t function as it should.

Another side effect is that cycling the lights (turning them on and off) can trip the check panel low beam indicator, which will alert you to a low beam issue—even if the lights are working correctly.

Here is a forum thread speaking to the same issue with pictures:

Download (PDF, Unknown)

This entry was posted on October 17, 2024 at 12:21 am and is filed under Interesting Stuff. You can follow any responses to this entry through the RSS 2.0 feed.