Pulsing lights...??????

[DallasTahoe]

So ive been going through my Hoe and doing some fixes that ive been neglecting because of too much work, but now im on to the next item of my list, I tend to work on my Hoe at night sometimes and ive noticed that while shes running I can look at the headlights against the fence and I can see a slight flicker, along with the the voltage meter just slightly flickering with the rhythm of the motor, and that's with nothing on but the running lights, when I have my stereo, front fogs, rear fogs, heater or anything else on it doesn't do it...That being said, ive gone through and done the Big 3 upgrade a while back with 0 gauge ground cable from battery to frame, and frame to motor, then 8 guage to body (which soon will be changed to 0 guage), ive left the factory ground straps intact and removed and cleaned the connections so im pretty sure im grounded pretty good... Im a novice at newer vehicles, older vehicles I can take apart and put back together blindfolded, am I missing something??

 

[xanatost]

Check the alternator. Mine was doing that and I changed mine out and fixed.

 

[DallasTahoe]

check it? Mines charging fine, I don't have any issues other than that, is that a tell tale sign its about to go out?

 

[xanatost]

Maybe not a sign that its going out but that its just getting old and not as efficient as it was when new. Does your dash lights dim in syn with your head lights?

 

[DallasTahoe]

yea it does, but like I said its just a slight flicker....hmmmm guess its time to upgrade it...

 

[xanatost]

Thats what mine was doing and when I upgraded the alt problem solved

 

[DallasTahoe]

ok I see, is there I saw some threads talking about a newer year alternator with more output that fits a 98 Hoe, any ideas which one? Part number maybe? I have a 105amp unit now, and like my Dad says if you replace it, upgrade it...

 

[mudslinger96]

I have a 02 tahoe 5.3l altenator on my 96 yukon perfect fit no mods required i believe it is 130 amp

 

[xanatost]

I have a 02 tahoe 5.3l altenator on my 96 yukon perfect fit no mods required i believe it is 130 amp

What he said. That's what I put in mine as well. I run a lot electronics in mine as well and will be putting on off road led lights soon. Sometime this spring I'm going to do the duel battery in mine but I will run one alternator with a switch. I would run two but I'm fixing to get a super charger and I don't even want think about trying to put all that under the hood and have it look good lol.

 

[inthechateau]

If you put a digital meter on the alt output you will find teh inconsistant voltage. Its from a faulty diode starting to feed back through the other diodes and confusing the internal voltage regulator. Once you change out the alternator the flickering will be cured. If you go too much bigger on teh alternator you might want to keep an eye on the battery condition. Higher amp output can cook a standard battery.

 

[theautoman21]

lights

make sure you check your grounds had same problem.

 

[DallasTahoe]

I run some electronics in mine, just my lil system and my gps mainly, my front and rear fogs, im not gonna go too big, just a 140, battery is good and ive done the Big 3, all my grounds and power leads have been cleaned and tightened...
So an alt from an 02?? Did it have rear air, 4x4 or any other specs other than 130 amps?

 

[SunlitComet]

sure the headlight switch is not flaking out on you?

 

[DallasTahoe]

No because even with the lights off it still does it

 

[SunlitComet]

so with the headlight off how do you notice the flickering?

 

[DallasTahoe]

well I still have the daytime running lights. Plus I can see my guage bobbing up and down... Here is something different though, this morning I started her up and the amp gauge was way above 14amps, like about 15 1/2, and its never been that high, its usually just below 14, so idk what the hell is going on??!!
I went to Autozone and had them check it and they the said the alternator was good, don't know how much trust I should put in their diagnosis, also had them see why my CEL is on and they said P0420 and P0430, seems unrelated to my light issue, so im pretty confused right now...

 

[SunlitComet]

I will assume you mean volt gauge. And if it did hit 15 your alternator is on its way out and it will onlly get worse. As far as the codes are concerned they mean that both left and right cat converters are worn out chemically so to speak. Fix you electrical problem first then clear your codes and see if they come back at a later date.

 

[DallasTahoe]

Ok so electrical problem is fixed, I checked out my grounds coming from battery to body, and they were fine but rusted slightly, so I cleaned them and the alternator cables to and from the battery and now the guage holds steady, no flickering!! Thanks automan21! didn't even think about the grounds since I recently did the Big 3, but I guess it goes to show that just because you recently fixed one thing doesn't mean that you shouldn't recheck it when running into problems... now if I can get the guage to stop going down at the same time the turn signals flash Ill be golden! oh well hopes and dreams!!
Thanks all for the input and suggestions, I followed all of them, fortunately I didn't have to buy a new alternator!!!

 

[christianctucker]

my lights keep flickering on my 2000 tahoe z71 when i press the gas it only gets worse i cant drive my tahoe at night cause the lights flashing so bad ive had my alternator and battery checked and they both came back fine what should i do ?

 

[saif najd]

my lights keep flickering on my 2000 tahoe z71 when i press the gas it only gets worse i cant drive my tahoe at night cause the lights flashing so bad ive had my alternator and battery checked and they both came back fine what should i do ?

I have the same but not as bad as yours and the alt is like 4 months old! I cleaned the ends of the cables to and from the battery but still the same