looking for insight , what would cause power steering pump to get very hot ?

Blocked flow output, similar to holding it against steering lock all the time. Look for plugged filter, internally collapsed hose, incorrect hookup if you just made some connections, problem with helm, or even just a problem with the pump internal valving.

lets ask what do you have as far as the pwr steering & pump and engine and year model ? Do have the stock steering actuator? do you have a power steering cooler ? What are you using as fluid and is it at the correct level ?

Impossible to answer without knowing a lot more info.

boat is a 43 black thunder, cable helm with the stock internal power steering valve set up , has had the external steering rams added but uses the stock steering valve set up on inside of transom, there is the standard power steering cooler ,

falcon the pressure hose looks rough we did blow air through it seemed ok but that is not indicative of full flow , we considered the internally collapsed hose as a possibility so we removed pressure hose and are have a new one made this week to rule that out . this is a friend of mines boat I am trying to help out
figured I would post on here maybe get some fresh thoughts to "steer" me in the right direction
thanks for your imput ( I thought there has to be a restriction somewhere but having trouble locating it)
the steering was already installed on boat when he bought it but it was a lake boat (ie not run for long distance couple of miles to cove whereas now he is on the Chesapeake bay so 20 to 30 mile lunch runs are common and this problem has presented itself
he replaced pump due to seal failing but it appears that the real problem was it got so hot that the seal melted

Is it hard to turn the steering wheel at idle rpms????

griff no you can turn wheel with one finger no pulsing steering works very smooth by smooth even feel at wheel and by visually watching drives turn

what kind of fluid ? I use the high performance GM non foaming, what CP performance recommended

you sure power steering cooler is even installed? and are you sure the tiny factory merc power steering cooler will handle external hyd steering?

I asked about the power steering cooler in post 3 as well. That is the first place I would look since he has one - what size he says its stanard , is it plumbed. correctly ? Did it get winterized properly if applicable ? possible too small of a pwr steering cooler