Excessive load on alternator?

[jdyates]

Hey guys. Just curious, I've heard people say that we shouldn't trust the gauge on the dash, but does anyone else have it dip pretty low sometimes? For example, with my headlights on (35w HIDs on their own relay harness), and the radio loud, it'll dip a few lines under 14 (like 12-13 or so) and stay there, and when I hit the turn signals, they will dip 2 or 3 more lines when the lights flash.

I have my entire truck converted to LEDs EXCEPT for the front amber bulbs, so does it really make sense that the gauge dips super low like that?

Also, back when the A/C worked, it would sometimes dip fairly close to 9v when the AC was on high. Should I be worried? It's got a stock 105 amp alt on it at the moment.

 

[Half Assed]

Buy a led voltmeter on ebay for $5 and wire it to the battery.

My dash gauge will drop to 10-11ish when the bass hits hard. My voltmeter will show about 11.2-11.5 volts. I haven't had any problems though. I don't have anything that draws more than the alternator can put out.

Blower motors draw a bunch of power 30+ amps. I'm not surprised the voltage was showing low. It never hurts to put a bigger alternator on though.

Have you upgraded the wiring (big 3)? I haven't completed mine yet, but I did upgrade the negative ground cable on the battery and I picked up another .5 volt on the dash. It really helps and I think it's the most important cable in the big 3 upgrade.

 

[tailpipe51]

big 3???

 

[Blind]

big 3???

3 wires are really important; battery to frame ground, engine to frame ground, and battery to alternator terminal. If you upgrade those to bigger wires you can have less voltage drop through resistance. Most people upgrade to at least 4 awg wire for all 3.

 

[tailpipe51]

3 wires are really important; battery to frame ground, engine to frame ground, and battery to alternator terminal. If you upgrade those to bigger wires you can have less voltage drop through resistance. Most people upgrade to at least 4 awg wire for all 3.

ohhhhhhh

 

[qukon 95]

you need to get the batt checked. may be bad cell causing alt a heavy load after truck runs see if batt is hot .it shouldn't be hot.

 

[JScott23]

3 wires are really important; battery to frame ground, engine to frame ground, and battery to alternator terminal. If you upgrade those to bigger wires you can have less voltage drop through resistance. Most people upgrade to at least 4 awg wire for all 3.

True, a bad ground can show low voltage on the gauge and cause other problems. theres a few under the hood you should check like stated.

 

[great white]

I did "the big two":

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Second alternator. Ambulance package for the 6.5

You can do a similar job with a higher output single alt, but I prefer the redundancy and option to swap a shorter belt on if one of the alts do calve on me in the middle of nowhere.

Very often, voltage/charging issues can be cleared up fairly well by pulling the battery terminal and cleaning them, as well as the chassis grounds.

The "big 3"?

Meh, I've done it before on several vehicles. I usually find if there's a significant difference it's because there is an already existing problem somewhere in the ground path that putting new wires on goes around.

The "big 3" sure isn't going to hurt ya (except where you end up bypassing fusible links and other shorting protection) but I'm not going to say it does a lot to help a healthy system either...

 

[West Mi Mudder]

I did "the big two":

You must be registered for see images

Second alternator. Ambulance package for the 6.5

You can do a similar job with a higher output single alt, but I prefer the redundancy and option to swap a shorter belt on if one of the alts do calve on me in the middle of nowhere.

I was looking into adding a second alternator, but was having trouble finding the mounts. GM doesnt make/carry them anymore from what i read online. Do you remeber where you got yours?

sent from my Galaxy S4 Yo!

 

[great white]

I was looking into adding a second alternator, but was having trouble finding the mounts. GM doesnt make/carry them anymore from what i read online. Do you remeber where you got yours?

sent from my Galaxy S4 Yo!

Made it myself.

Pretty easy; just a piece of flat steel, a pulley and some bolts.

That pic above isn't mine either. It's one I grabbed off the net....