The Japanese-made Fenders do have some slight serial number differences (typically a "J" serial number prefix). I believe this was a mistake on Fender's part using the same prefix for both U. Below are some examples of letter prefixes used in recent serial number schemes.
In March 1985, CBS sold Fender to a group of private investors.
The serial numbers do not reflect this change - Fender continued to make instruments using existing serial number schemes.
The new Fender did not acquire any physical assets of the old company, just the name "Fender".
Hence during 1985 to 1987, production of Fender guitars was only done in Japan, while USA Fender created a new factory in California. BUT note that the "E" and "N" series does sometimes appear on "made in Japan" models. In any case, if it says "made in Japan", then it is... Fender has recently (in the last 20 years) introduced LOTS of different serial numbers schemes, depending on the country the Fender was made (USA, Mexico, Japan, Korea, etc). Sorry, since I do not collect new Fenders, I don't really keep track of these things.
This is only visible when the body and the neck are detached.
Almost all Fender guitars have the date stamped or written in their neck.
Most people think that the date stamped on the heel is the production date but that’s not really true.
So in many cases the exact date for a specific guitar is not exactly known.
Here we’ll help you to understand the Fender serial numbers and how to determine the age of your Fender as well as any Fender that crosses your path by explaining the Fender serial number system.