Hi, welcome to the forum. If you re-post in the vehicle specific area for the Voyager 4th Generation, you'll probably get more responses.
My money would be on that the bottom of the radiator is full of sedement/blocked.
To check, when it's up to temperature, try squeezing the top radiator hose. When this has happened to me in the past, this has been rock hard.
Another thing is that the bottom of the radiator will be cold whilst it's really warm further up.
That's a bit harder to check though, due to the fans. I'm unsure if the ones on the voyager could be safely blocked to stop them turning or not. I suppose disconnecting them from a power supply should work, but if you are going to check this way, please be very careful and make sure you can't get hurt.
