Lights flickering/dimming

[greenallgreg]

I'm having an issue with the lights flickering on my 91 W250. The headlights, taillights, dash & radio lights flicker when driving and idling. Any ideas as to what the culprit could be?

 

[B.G. Smith]

Could be the light switch going out but most likely is the alternator, either the brushes are worn out or the voltage regulator is acting up. The regulator is in the computer on your truck I believe. Disconnect the small wire on the alternator and see if that stops the flickering. The alternator will stop charging with the wire disconnected. bg

 

[Bluebird]

I am sure it's the headlight switch, I've done 3-finally I installed a relay Kit from LMC truck # 36-3580 w/ single headlight
Or #36-3581 w/o dual.
Replace headlight switch first, immediately install Kit. Please research all post in 1st Generation to verify my repair. Mine has been installed over a year-long No Problems!

Blue, Patrick