1979 mercruiser trim won't go down, pump running.

[sparky895]

I have a 1979 Beechcraft with a Mercruiser 470. The trim will go up but not down, the motor is running, i rebuilt the cylinders and if i crack the line on the drive it will go down so it is not stuck. It was stuck before the rebuild from corrosion in the pistons. I have power on the green and white wire when pushing the down button but i don't hear a click like up. Plenty of fluid in the drive and i did bleed the lines as per manual. Fluid looks good.

Thanks

Sparky895