Have an 86 Iroc LB9 that threw a code 53 yesterday. At times the volt guage would go up to 18 volts. When I popped the hood battery water/acid was bubbling out. I took the alternator out of the car and tested it at Autozone and it passed the tests. I also refilled the battery back up with distilled water and had that tested and it was fine. So I hooked everything back up and cleared the code. It happened again today though. Any idea on what is causing the problem? Any help is appreciated. Im sure all that voltage is not a good thing.

 

i had the same problem with my 86 trans am and it was the alternator. the test stands autozone have can't spin fast enough do duplicate the problem. i spoke to the manager and told him theres no dam way i was gonna put it back in my car and fry everything because of their flawed test equipment. he gladly gave me a new one and all was good.

 

Interesting. Do you know what the problem with the alternator was? The voltage regulator? I am pretty sure I bought the alternator from an Autozone and have a lifetime warranty on it. Hopefully I can trade mine in and get a new one.

 

it was the voltage regulator. and they are lifetime warrantied so you should tell them your situation and demand a new one.

 

Went to Autozone and was able to swap alternators and get a new one. Im hoping the code doesn't show tommorow. Thanks for the help

 

Well the guy at Auto-Zone, probabaly got 18v and was like
"Yeah its good and sh*t"
Honestly its got to be the alterator. The voltage regulator goes out and nothing controls what the alt is putting out. yes a regulator can be repaired but its alot cheaper and easier to replace the entire alt.

read upon this article for some info.
Voltage regulators