Are you talking about a relay box that looks this? I since replaced mine with the CDI model as shown in the second picture ....

Yes we tried to use the old relay box. But this Outboard is a 1974 200. The relays would not push enough current to run the motor. The trim motor would barely spin. So now I am trying to figure how to make this dam thing work right. We might just run dual Mercury trim tilt solenoids.

it all depends on if the trim motor is a two wire or three wire motor. If its a two wire, the ground is always constant and the up and down are set by the solenoids or relays. If it only has two wires, then the at rest position of the relays need to be to ground, when the relay is activated, it breaks ground before allowing the voltage to feed thru, the opposite relays is supplying ground to the motor while the activated relay supplies the power. You can use the small auto style "cube" relays if you get the correct ones

It's got the three wire trim motor. Constant ground. Then a wire for up and a wire for down. I have the relay box shown above and it does not work. The trim motor barely makes a sound.

check you ground real good, try a voltage drop test while the motor is running.

Make sure its at lease a #8 wire 30 plus amps, What is the amperage on the relays, bypass the relay box as a test and see what happens it could be faulty relays or bad pump. Post some pictures it helps ...

We have been tilting the motor up and down by putting the trim motor wires straight to the power and ground. No problems there. He bought the relay box of ebay for what we thought the motor was. Then I discovered it was a 74 200. Can we change the relays to higher amp relays? Or should I go with my original plan to get two Merc tilt trim solenoids for $50. The motor is 30 miles away fyi.

Yes if the wires are rated for it up the relays to a higher amps will work be sure to completely check from switch to motor for correctly rated wires.