Unfair treatment

[cushman350]

My son is 20 and has used Wells Fargo to purchase one vehicle but had to be co-signed by me. He paid the note and now wants to borrow again from them but on his own credit worthiness. He has no negatives on his CR and has three open charge accounts open all current. WF says that's too many and his credit history is too short. They want another co-signer. I think he is being mistreated for all his work at trying to build his credit and being penalized for having "too" many accounts. What gives? Me co-signing doesn't do his credit any good does it?