Brake light, Oil light, Battery light - A/C does not work

[OscarMeyer195]

While driving on the freeway with the air conditioning on, it turns off by itselft. When the air turns off the brake light, oil light, and battery light goes on, on the dash. I also notice when this happens the voltage on the battery drops to 10 volts. The voltage is usually at around 14 volts. This can last from 30 seconds or sometimes up to 5-8 minutes.

After a while all the lights go out and the air starts to work again.

This happens mostly at highway speeds.

I've checked all the fuses and haven't seen any blow ones.

The car is a 95 Rodeo, 6 cylinders.

[krimes13]

Classic symptoms of a failing alternator.
I'd replace before you're stranded.

[Ramblin Fever]

Totally agree, this is classic for an alternator failure in the V6's.

I highly recommend against a remanufacturered alternator, when purchasing a new one. Try to find a brand-new "Isuzu" alternator, they are worth the extra $$, and they aren't cheap.

However the hassle of the remanufacturered alternator just isn't worth the headache; these trucks hate em and will eat them up FAST!

[OscarMeyer195]

Do you guys/gals have any recomendations on where or website to purchase an Isuzu alternator?

Thank you for all your help.

[Ramblin Fever]

Just got myself a brand-new one, Bosch to be exact, through my "Imports Only" mechanic. Wasn't gonna have him DO the work, but I couldn't find a NEW Bosch or Isuzu alternator anywhere in this town!

My previous one had been from Checker with a "lifetime warranty" - yeah if you want to spend an hour or so every 3 months replacing them - these truck's just eat em!

But, I have to wonder how good the alternator was to begin with.

To be honest, I don't know where you can get a NEW one, Bosch or Isuzu without having to go through a mechanic shop or dealership - however, the Isuzu dealerships here in Colorado only sale refurbished Isuzu alt's. Keep in mind, however I do have the 97 Rodeo, your year may be easier to locate.

Many of things can be linked, I've learned, to a failing alternator - for the last 3-4 months, I thought this thing was in serious need of a major tune-up, despite the fact it gets one every 2yrs. The way it was running this summer, you'd swear I'd never had it serviced.

Had slight misses, only occasional true take-off power, no a/c half the time, etc.

She now runs like a bat out of again!

Don't wait as long as I did to change it out - i was very lucky this truck didn't just croke somewhere, getting less then half amps from that stupid thing.

[WayneO13]

I have the same problem with a 1994 Rodeo V6 but it happens when I start the car in the morning or after it sits for 4 - 5 hours. After I drive the car for 10-20 minutes the lights go out and the A/C comes on. Sometimes if I stop and restart after about 10 minutes the lights are out and A/C works. Could the alternator also be causing this problem?

[tomlcollins]

Wayne,
If your lights are going OFF as you drive, then you're alternator is charging fine. As a matter of fact it might even be overcharging. You need to replace your battery, and you shouldn't have any more problems unless of course you are overcharging.

[2eyefishclaw]

this guy should have his alt. and batt. tested and not by some stupid parts house dont just replace parts untill you get it right
but I would bet that there is a problem with the alt. from the description

[WayneO13]

I just replaced the battery with a DieHard Gold and the same thing is happening.

[2eyefishclaw]

Imagine that.
Now that you have wasted your money on something that did not need replacing get your charging system tested I bet you will find that you need an alternator.

[Ramblin Fever]

Originally Posted by 2eyefishclaw

Imagine that.
Now that you have wasted your money on something that did not need replacing get your charging system tested I bet you will find that you need an alternator.

Doesn't always mean he wasted his money. Sometimes they both go, or are going; which was the case for me. I too replaced my battery a good day before my alternator, however, mine were definitely both on there way out. Battery, though still obviously functioning at the time, was swelling and starting to leak acid.

So he may not have fixed the obvious problem, but he may have needed a new battery anyway, which will kill a weak alternator and/or starter.

[2eyefishclaw]

but it is much cheaper to just have it tested

[Ramblin Fever]

True!

[vokia83]

My battery light, brake light, and 4wd hi light come on and the AC cuts off. Voltage stays constant @ about 13. Just replaced alt and battery and it still happens. Doesn't seem to do it nearly as much at highway speeds. Any ideas?

[Ramblin Fever]

Weak alternator. I know you just replaced it, but that's what it is that's causing the issue - specially if you bought a remanufactored alt, rather then OEM Isuzu or BOSCH.

Went through this myself all summer, after having replaced both battery & alt as well - turned out to be a bad reman. alternator

These trucks do not like weak voltage, and they will eat at whatever may be slightly weak.

Check your belts as well