I have a 99 passport that gives me 13.5 volts at idle and 13.8 at rpm.

Im curious what do other people have with 98+ or higher, becuase if im not mistaken alternators put out 14.6 and I thought I read that also in my manual.

I've added on some more grounds of larger size to help but it didn't seem to make a difference. I got a Alternator to Pos Battery, Alternator to Chassis, Chassis to Neg Battery.

Anyone want to give me a simpling of there voltages?

I've had my alt tested, some people say its bad, some people say its fine. I took it off the block and they guy tested it and said it was fine. But then a guy the other day tested it and said it failed the load test. Soo ehh..

I replaced it with what I thought was a good alt at one point and I saw no increase or decrease in my voltages.

Im thinking about trying again with a bosch alternator.

Thanks

i'm a big fan of rebuilt by bosch alternators and starters.
as to your volts, they do seem low, but it can depend on what demand (load) is required of it. that's what the load test is all about. you can simulate a load test by somewhat draining your battery by running the lights while engine is off, and then starting it with all the electrical draining stuff turned on -- lights, brake lights, blower motor, 5,000watt stereo....
when you start it, this will be the point that the alternator should be cranking out it's max amps and volts.

the battery can also be at fault here. have you had that tested? a weak cell, or shorted cell, or just plain worn out, will keep the alternator from cranking out its max.

//bc

After the car is warmed up, I get 13.5 with nothing on.

I use a Yellow Top Optima, and I've used a Gold Duralast, but are fully charged and working properly.

I've never seen above 14. I only see 14 even when the car first starts, and it slowly goes down withn 15minutes. And 13.8 is as high as it goes when giving rpm.

The 13.5 is at the battery.

Could be a weak, but not failed alternator.

Any noticeable problems electricaly other then the voltages? Isuzus seem to be picky about having just the right power.

Also how are you testing the voltage? Hopefully with a multimeter (I prefer digital).

mine outs out 14.2 warm. year 2000

The odd thing is, I put a what I thought was new brand new built alternator on it and the voltages didn't change.

Im testing with a multimeter digital at the battery.

Im very close to buying a Bosch Alternator.. lol

Test Your Voltage At The Nut Where The Battery Cable Bolts To The Alt You Might Have Bad Battery Cables

at the nut on the back of the alt it should be about 14.3. if it is u know the battery cables are bad

Its not, its mid 13's. Im running my own cable from the alt to the bat 0 ga. I've used it with and without a fuse so fusing it made no difference.

This is with and without a new alt. Both alts reported the same voltage.

is ur tensioner good belt tight

on the other hand the alt is doing its job th battery dont need much of a charge your electrical system might be efficent if there are no other problems i wouldnt worry about it untill it drops below 13 volts

The alternator has been tested its outputing 44amps max.

Also I now have 14.6v at idle at night, and 14v at idle during the hot summer day.

I added a body to chassis ground, and (what I think fixed it) changed the negative battery terminal.

The alternator has been tested its outputing 44amps max.



aren't they 90 amp alts? sounds like your alt is toast!

They are 90amp alts. But everyone says when I have my alt tested and it outputs 44amps its just becuase it doesn't have the proper load.

Autozone and Advance Auto Parts test it with the machine they hook to the car.

It will only put out the amperage that is required by the load. Apparently their testers dont put much of a load on it when they test.

i believe on a volts amps tester you can put any load on it you want?

It will only put out the amperage that is required by the load. Apparently their testers dont put much of a load on it when they test.

I have a aftermarket audio system, some guy told me while he was testing it to turn on my audio system. It said the max amps at that time was 26. But the max volts was 14.4.

So see how im confused lol.

My system was going preety well, to the point where I have problems, and the alt only charged at 26 amps.