Having trouble with the transmission not changing gears.

I have 1987 p30 step van and I've had this problem before and I had
someone fix it twice already but it's not changing gears like it should, one or
twice it will but it's worse now and they guy told me it was just some pull and
or fuse that was disconnected.  I'd run it back to his shop but I don't want to
burn up the engine in first gear trying to get it to me plus a tow would be
$300 or even $200 just to get it to someone closer.