Z32 NA AT - hard shift into 2nd, can't shift into 1st
 

First post ever, on any forum. Not a mechanic, but I've been buying/selling cars for 16 years. Recently picked up a 93 300ZX NA AT 1 owner with 125k. Vehicle has rough shift only from 1st to 2nd, and I cannot shift it into 1st at all. The shifter goes as far as 2nd, and no further. The car is 100% original, other than some bodywork on the front end which appears fairly old.

I tried to pull auto transmission codes with instructions from TT.net, but didn't get very far because I could not find a shift lock release button.

Any advice would be greatly appreciated, even if just to point me to a post that speaks to these problems, because trust me, I've been looking.

Update
 

Ok. The not shifting into 1st was due to interference from a harness on the outside of the transmission case. I got the harness back into the tie-down on the transmission, and now I can shift into all gears. Probably not a common problem, but I thought I'd mention it in case anyone does experience this.

I was able to pull the AT transmission codes, but it didn't give me anything because I disconnected the battery while trouble-shooting the "not shifting into 1st" issue. I will post on my progress once I drive it and can pull the codes.

I am hoping this will be a solenoid or electrical issue, and not something internal in the transmission.