Voltage dropping help please

[Jared Harper 0]

I was wondering if anyone can help me with this. I drive a 2005 colorado with a HO 200amp alternator with a deka intimidator group 34 under the hood and 2 group 31's in the bed. The big 3 is done in 0 gauge, Two runs of 0 gauge to the rear batteries. I measured the voltage at the amp. At 1/2 tilt I was at 13.4 at idle, as soon as I turn it down it jumps back to 14.4. As soon as I crank it to full tilt it drop to 11.6 at idle. My amp is saz3000d at 1ohm. I think I covered everything. Do I have a problem somewhere or do I just need more. I didn't want to piss the neighbors off too much because so I will have to measure the voltage again at 2000 rpm to see how much difference it makes.

[Quentin Jarrell 671]

make sure you have all your connections tight from the alt all the way to the back. I had a tahoe do the same thing because of a fauty street wire 1/0 gaude ring terminal.

[shizzzon 461]

Turn the car off and check voltage level of batts in the rear.

For it to drop so much at idle, it should also drop that low with the vehicle off playing the same song, but with Group 31s, i think that might be a little big of a drop .

They may not be completely charged, loose connection as stated above, etc.

So, check float while car is off, check voltage at 2.5 - 3k rpm and see what the difference is.

[bobonit 5]

Check your belt on the alternator, if it is slipping under load that could cause your voltage drop as well.

[KU40 173]

Plus don't forget that at idle your high output alternator is likely to put out even less current than your stock one. You may be only getting 50 amps from it at that point. Most HO alts are meant to be ran at higher RPMs, whereas stock alternators are designed to have a more even power output across the RPM range.