Just installed a new alternator on monday, and today after a bunch of stop and go traffic, I was sitting in a friends apartment building parking lot waiting. The car was putting off a lot of heat, felt like I had the heater on full blast, but the car was running only at 220. Suddenly I could hear humming coming from the back of the car (gas tank) and a strong smell of gas, then the volt gauge goes up to a hair below the top red marker and the SES light pops on. Ends up throwing a code 42 and 53. These are both related to the electrical system.

Few hours later on the way home, the volt gauge would periodically jump up in volts and it was obvious because all my gauge lights and head lights got brighter.

Is my new alternator to blame?

**Edit**

After some research I have learned that it could be the voltage regulator inside the alternator. But when checker ran their tests on the alt. it checked out to be within operating specs. I was watching their voltmeter and it was showing 14.5 to a max of what I saw to be 15.5. And it fluctuated a lot inbetween those two points. I also checked the plug for the alternator, and that checked out ok.

Another thing is my car is an 89, and code 53 is suppose to be for a VATS problem. Both codes were thrown though when the voltage spiked so how could VATS be related?