Headlight Flicker - Possibly Alternator? (1 Viewer)

[SHTF]

I have a 2001 TLC with 187k and noticed the last few months that the headlights will flicker dull then back up while interstate driving... Still have original 9006 setup for headlights. Kinda looks like I'm flashing my lights off/on almost. Have a 2 year old Optima battery that should still have life in it.

Starting to think the regulator might be going on the OEM alternator, never replaced it yet, anyone else have this problem?
Thoughts.... Thanks!

 

[Jordan345]

Mine did that as well and the recommendation from the forum was that the alternator was crapping out. My truck would sit idling from a cold start and pulsate the headlights while warming up and while driving until warmed up. This started occurring after a starter contacts replacement. I have a red top and yellow top optima as my dual battery system. I had advice to get the voltage regulator rebuilt, but thought a 'new' reman'd unit was just better. Just ensure you go denso oe unit, not Bosch or some crappy u.s. brand. Since replacement I have been problem free for a year. Mine had 120k miles when it went

 

[SHTF]

Thanks Jordan, yeah I'm not getting the bearing noise that I see on the forums but do think the VR is going. I noticed when idling if I step on/off the brake fast the lights will flick too and then come back up. Any idea how much the VR cost is vs the Alternator?... I might replace the whole thing since I'm almost at 190k and never had to replace , I'll stick to the denso also

 

[trackmur]

I've seen a similar flicker when cold for about 300 000 km. I'm not worried about it.

 

[Jordan345]

I think the cost of the vr rebuild was about 100 dollars here whereas I picked up a denso alternator for about 250 plus shipping to Canada. There are good options on amazon for the 100 amp denso. Just double check you're getting the denso and the part number works for your cruiser.

 

[mobi-arc]

Voltage regulator is internal to the alternator and costs about $20. In all likelihood, the carbon brushes are worn and starting to lose contact with the slip rings. I can't remember if the brush-holder and regulator are one integrated assembly or separate. If separate, chances are you could replace the brush-holder assembly which runs about five bucks, and replace the bearings, and put another 180k on it.