Astro Van alternator problems


#1

Hi everyone! I own a 2000 Chev Astro van. About 3 months ago my alternator suddenly stopped charging, and I took it to my local shop.I had a small hole in one of my heater hoses that was spraying antifreeze right into the alternator. The replacement alternator burned out in 1 week. The shop could find no reason,and they said maybe it was a defective rebuilt. The next one lasted about 2 months, and this week number 3 went down. Last nite #4 stopped charging. The guys at the shop have been very good, and have checked every source they know of for the problem. They suspect a bad ground wire. Does this make sense?


#2

It could be. Also check the connections under the rubber boot of the positive battery terminal. Corrosion can build up unnoticed between the two leads.


#3

Check the large postive cable that goes down to the starter,this is commonly loose


#4

thanks I will check it myself.


#5

Thanks I will check it.


#6

When a good alternator is installed again I would check the voltage drop between the alternator output and the positive battery post while the engine is running. If things are good you have less than .25 volts across the connection. Check the ground cable also the same way.

Another thing to check is the battery to make sure it is ok and the field wire of the alternator to make sure it isn’t grounded and causing the alternator to produce full output.


#7

The shop should check the amperage draw on the alternator output power wire, with all accessories (A/C, fans, radios, lights, etc.) turned OFF. The amperage should be low. A comparison, of alternator amperage draw, could be made with another car which isn’t having problems.
If the amperage draw is high, it will have to be chased down through the battery, and wiring (partial shorts, or other high amperage draw causes).