Is there a way to install OEM keyless entry on a 95 150 that does not have the module under the dash?

 

It would require getting the module, a fob, and programming it. The factory stuff is usually pricey even in very used condition, as well as having antiquated technology.

You are better off going with an aftermarket system, I got a brand new unopened keyless entry remote starter from someone on ebay for $30, bulldog r1100, took like 20-30 minutes to install. I had previously installed the 1200 model with security bypass on my GFs Cadillac because it was cheaper to install a new one than buy and have the FOB programmed at a dealership, plus original didn't have remote start.

 

Even if he got a module and fob it still wouldn't work unless his truck had it from factory.

If it didn't he wouldn't have the wiring needed to make the factory keyless entry work.

 

I read it as though it had been removed at some point not that it didn't come that way. Either way it's still easier to go aftermarket.