h4 bulb burning dim (1 Viewer)

[Toyote]

I recently upgraded my headlights to some Hella h1/h4s and @slcfj62's fantastic harness. Finally real lights!

3 months in and my driver side h4 started glowing very dim; pulled it and replaced it with new and that side still runs dim w/ the new bulb... just curious what might have made this happen. Looks like corrosion of some kind on the bulb I pulled; strange because was using dielectric grease on all connections (or is that the problem?)

 

[Output Shaft]

There is a wide spread misunderstanding about the function of dielectric grease.

Dielectric grease is an electrical insulator, not a conductor. It should never be applied to any metal to metal electrical contact. Ever. It's primary purpose is for coating the inner boot of spark plug wires to ease in removal and increase weatherproofing.

 

[Toyote]

Lesson learned then.

Does it follow then that the new bulb might be burning dim for the same reason (I did not apply grease to it at all, but maybe a small bit of residual is in the socket?)

 

[LAMBCRUSHER]

does passenger side lamp have diminished output as well? If not, swap them out side to side to TS the lamp vs harness...I have had 2 new parts be bad right out of the box; less coincidental with more otherworld manufacturing happening...

 

[rat]

9/10 my issues with lights have been bad earth/grounds.. or bad bulbs, cheap & easyto fix..

 

[vasellers]

Had the same issue with the same harness, found that the OE wiring had some tiny cracks in the insulation and was grounding it out (SLCfj62 told me to make sure the OE wiring was in good shape with no cracks but did I listen NO!!) Wrapped the cracked areas and all works great now, has been almost two years and no issues.

 

[Toyote]

Thanks for the replies. Sounds like a grounding issue most likely. I'll chase that stuff down and report back.

@vasellers Do you remember where the cracks were on your OE wiring?