The car is a 2000 Toyota Camry XLE with V6 motor, auto trans, 187K miles. The car dies with my wife driving and won’t restart in the supermarket parking lot. Typical low charge battery, some dash lights and clicking when you turn the key to activate the starter. Troubleshooting leads to a bad alternator.
I get an alternator from my trusted NAPA store (remaned unit) and it looks like the right one. I swap the new one in the car and all goes fine until I tighten up the serpentine belt. I run out of travel on the tensioner and the belt still has too much slack in it. I start the car anyway and get the belt squeal I expect and shut it down immediately. I spend a few minutes rechecking everything and it is a puzzle? I get my tape measure out and find the problem - the old alternator has a 2 3/4" pulley, and the new one measures just 2 1/4". A full 1/5" smaller diameter pulley.
I consider changing the pulleys, and consult my car savey electrical engineer brother who says the pulleys are a bear to remove and it is not a good idea. Plus, the two alternators are going to spin at significantly different speeds. Next I call NAPA and they will order in another alternator, which should come with the correct sized pulley, but perhaps not. The replacement won’t be available for several days due to the upcoming weekend. I have other cars so I can wait.
The plot thickens, perhaps the old alternator isn’t the OEM alternator. I remember my son had starting problems when he had this car at college and I believe the result was a new alternator some 4 to 5 years ago. Can anyone confirm for me what the OEM sized alternator pulley really is for this car?
What are the pros and cons of just putting a smaller serpentine belt on the car and using the newly installed alternator? It will be spinning faster than the one that came out of the car, the pulley is about 20% smaller. Will this 20% difference result in overcharging? Will it put the alternator rpm’s out of the design range and shorten the life of the bearings? These are the possible con’s I can think of. The main pro is a new belt will go on in a few minutes and I’m in business. Otherwise I wait a few days and have to swap alternators again.
Would a pro mechanic just put on a new belt to satisfy the customer who is without a car, or tell the customer the part was incorrect and a new one will be on the car in a day or two?
So, that’s the story. Are there other options I’m not considering? Opinions on whether the new alternator is OK to go with a smaller serp belt?