ousig2408

of course a higher output alternator will solve most issues - that is the powerplant.
it is more complicated than just putting on a cap or new battery, there are lots of other variables but if you think about what is happening it seems that you are overstressing the electrical system at peak demand (loud music with big bass for an extended time). that is the 1 thing a properly sized cap is designed to smooth out - provide the quick power during peak moments. It will not solve all problems and the installer is somewhat correct. before people used capacitors incorrectly and did not understand what they actually did.
but the Tahoe has a pretty beefy stock alternator (I think it is 140 or 160 amp) so it can put out around 2000 watts at 14 volts or more depending on the amperage and engine RPM. that is plenty of power to run a 1500 watt stereo. keep in mind yes your stereo may be able to use 1500 watts but that is only during MAX power, normally even when it is pretty loud you will be using 1/2 that power at the most. and also when your truck is at idle the alternator is not putting out near the amperage so if your lights dim when you are sitting somewhere but dont when you are driving that will tell you that you are asking too much from the stock alternator.

if your amps are cutting out that could be from a loose wire (speaker or power or ground) or they are overheating/clipping. most have certain color of lights on them to show you what is going on if there is a problem.

honestly i dont see how with your system size you would be having ANY issues with power demand. in my acura the alternator is only 105 amp and my stereo can pull 1100 watts at least. I have 0 light issues or voltage drops (based on the digital voltage readout on the cap) even with the heated seats on high/fans on high/headlights on AND with the music blasting.

I think adding both caps and your new battery "should" solve most issues. if your caps have a voltage readout that would be ideal so you can monitor it

fox7seven

Thanks for your reply. I have another update, please read:

After 2 days of having the new battery they tested the alternator (at the stereo shop) while idle the tester read 14. something then it starting to drop to 13. something then down to 12. something WITH THE AC off and my sound system off. So the guy told me " your alternator is failing because it just shouldnt be droping just like that " > So i think is time to replace it now. My budget is $300.00 any good websites?

Also can i install it myself? how hard is it to install it?

Thanks again!

ousig2408

ok I may know the reason for this
our vehicles do not always engage the alternator fully if it is not needed. meaning sometimes it will charge at 14.4 volts then it may drop off to 12 or less when the battery is fully charged. it does this to "improve" fuel economy by disengaging the alternator clutch but that is debatable. anyway you may notice when driving sometimes your volt meter will show above 14 (above half) then sometimes you may look at it is showing less than half. at that time it will be reading much under 14 volts.
SOOOOOO if it is showing 14 volts it is probably fine honestly

JimJ

Don't believe the alternator has a clutch. I think the output is controlled by changing the field current but it is a function that is computer controlled to save that 1/10 th of a mile per gallon and probably the root of many of the electrical problems in our vehicles. WHIZ Kid engineers.

ousig2408

Jim you are correct - that is what I meant but wasnt clear. on the same note I wonder if an aftermarket alternator would work with the system we have or if it would cause issues?

kevinkpk

Alternator works with either an internal or external voltage regulator, the field voltage is controlled to the field by the VR. It only knows that it is set to 14 or so volts, and to keep the field excitation voltage to that level irregardless of what is turned on i.e. headlights, the vr will increase field voltage to maintain that 14 volt output, or reduce it as load is reduced. When an alternator output current is rated i.e. 65 amps, it will produce that current at 14 volts. The battery is wired in parrallel with the alternator.

ousig2408

do you know if that all applies to the tahoes charging system? Ours seems to charge at the full 14.4 volts based more on battery charge than anything else

kevinkpk

It applies to anything Tahoe, Ford, buick, ect. I gave the 14 volts as an example

73shark

The NBS GM SUVs use a computer controlled charging system as ousig2408 described.

kevinkpk describes the older system used for eons and IMO worked much better.

ousig2408

that is what I thought - I wonder what other major makers use this new system now?