onestar

Looking at an '86 model 4cylinder/auto 4Runner, it runs fine but the automatic trans seems to skip 3rd gear and go directly to overdrive. The O/D button on the gear shifter doesn't seem to do anything and clicking it on and off doesn't make any difference in shifting and no lights illuminate on the dash. Anyone on here know if this is a quick fix like a switch or relay or is this an internal issue? A friend has this truck and was wanting to sale and was honest about everything that wasn't right with the truck. He has had this truck for 5 years and said the trans has done this since he has owned it. I am just looking for a beater and not wanting to spend a lot of money on fixing the truck up. I'm not real familiar with these transmissions and it appears to have 2 trans pans instead of one. Thanks in advance.