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Davo, Master technician
Category: Car
Satisfied Customers: 3253
Experience:  ASE Master Technician/Advanced Automotive Diagnostic Technician
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GM: vehicles are plagued with flickering headlight problems..narrowed

Customer Question

It appears that for some years now , many GM vehicles are plagued with flickering headlight problems.Has this issue been narrowed to a few solutions?
Submitted: 7 years ago.
Category: Car
Expert:  Davo replied 7 years ago.
The reason they flicker is because the voltage regulator is controlled by the pcm in my opinion.To the best of my knowledge GM has not found a cure for it yet.They have tried some patches but none have been successful.Again that is my opinion.They need to adress the pcm software to "Soften" the charging system variations.I had a customer that got a fine for flicking his headlights to warn of a speed trap when he was not doing so do to the flickering.I wrote a staement for him.To this day I have no idea if it helped him in traffic court.Some cars on the road today look like you are flashing the lights when you are not because of the beam desin in the new composite headlamps.The beam is directed quite well for the driver but onlookers will see it as flashing the lights.
Customer: replied 7 years ago.
I'm sorry.I had just posted a motorcycle question and thought that was what I was getting an answer to. I had posted this particular question about the headlight flickering some time back and had really not given it any further thought after doing some research on the subject.
Expert:  Davo replied 7 years ago.
The site shows both questions being asked today.If you don't get an answer for your Harley question let me know.I will contact a few people for you.My wife and I both have Sportsters.Have a good day and keep the shiny side up.
Customer: replied 7 years ago.
I think the reason it showed both answers today is because i hadn't completed the sign-up(which I just did a few minutes ago) when I asked the first question about the GM headlight flickering.Sorry for any confusion. I've got a really sharp 01' road king classic that I'm still making payments on. It's my first ever H-D and I reallly love it! But after doing a web search on the early magnetti marelli efi (which mine has)I'm concerned to the point that I'm actually considering trading up to a 02' or newer to get the "better" delphi efi.Anyhow' thanks and sorry for any confusion.
Expert:  Davo replied 7 years ago.
You could always go aftermarket you know.When you did the big bore kit was the bike remapped?
Customer: replied 7 years ago.
I purchased the bike with the kit already installed and got the receipt where the dealer had installed it and it shows to have been remapped.It really doesn't run "bad" but my main concern is that it appears to run somewhat "rich" (black soot inside muflers)and the excess combustion byproducts as a result are likely to accelerate oil contamination and engine wear.
Expert:  Davo replied 7 years ago.
Harley pipes are supposed to be black inside.If they are not you are running too lean and will cause engine damage.The oil will get dirty looking as well it is the nature of an air cooled beast.
Customer: replied 7 years ago.
Well then maybe it's not all that bad after all.But i would like to have a lower(and more consistent) idle to "accentuate" that Harley "lope".It more often than not idles higher when outside temps are warmer than when they are cooler.Hey,thanks for your input.Just in case you care to take a look,here's some pics of my hog:
Expert:  Davo replied 7 years ago.
I think you need a remap or an aftermarket tuner for the EFI.With the aftermarket models you can download into a laptop go to the bike and download the map or move your desk top closer so you can.dealers charge big bucks for a remap and want to charge you dyno time to tweek it.I see your mileage is under 16K.Dude you have at least a bare minimum of 100K to go before any serious work needs done and it will mont likely be more than that.Sporties go well over that mark if talen care of properly.You won't see that in a Jap bike.Harleys don't leak oil anymore either from what I have seen.The older ones still do but not the newer ones.If you still want a newer King stay away from the six speeds for now.They have some noise/trans problems HD still needs to work out,Nice bike by the ay I would love to have it in the stable.Iron horse stable that is.
Customer: replied 7 years ago.
Thanks for the heads up on the six speeds-good to know.Even if i did trade up, I'm only thinking something in the 02' to 04' range(not yet independently wealthy:)if you know what I mean.Thanks for the info on the engine life expectancy too-I really had no idea as this is my first endeavor with H-D.I keep thinking I'd like an e-glide for more cool weather comfort as the wife and i really enjoyed riding up through late fall 07 and early spring 08(though we froze our a***s off a few times lol)

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