I am trying to help a buddy of mine get his drive trim to work properly. The drives will trim down but not back up. We used a jumper wire and got the pumps to run up also, but they won't work with the switch. The fuses are not blown either. Any ideas?

each direction has it,s own solonoid,check to see in the switch is activating the solonoid.

Trim limit switch bad???

The switch isn't activating the pump for some reason. But the solenoid works if we use a jumper wire. Where would the trim limit switch be? Is it on the pump? The original switch broke today while launching and got stuck running in the trim up position. But it never blew the fuse.

Will it raise with the trailer switch? It should as this bypasses the limit switch and goes directly to the up solenoid. Don't know what your working on but most have the limit switch on the port side of the gimble ring where the drive hinges.Wire connectors would be back by the transom inside the boat. Volt meter can track it pretty easily. Disconnect connectors. Purple-white from helm should be hot with trim up activated. If not problem is at the helm switch. Blue-white from helm should be hot with trailer activated. If purple -white is hot when activated reconnect it. Now hit the trim up and see if the other wire from the limit switch is hot WITH THE DRIVE DOWN. If current isn't passing through the limit switch with the drive down than the limit switch is bad. Blue-white should be hot anytime the trailer button is activated as it bypasses the limit switch.

To test for bad trim limit switch... In Phragles diagram remove the purple and blue bullet connectors. They are probably near the pump. Use a jumper/ paperclip to jump the purple and blue wires. Pump side should be female side. Then try using trim switch. If it works properly you have a bad limit switch. You can run it with the jumper and not use the limit switch we do it all the time or you can replace the limit switch. If the jumper doesn't fix the issue you most likely have a bad trim switch or a problem in the harness.

A test light would be a handy tool here .

I had this problem for a while, turned out the wiring for the trim limit switch had become damaged and it was occasionally shorting out near the gimbal assy. Very frustrating to find. At least I have a spare trim pump now.

If you jumper the solenoids, they will work, however, you are bypassing the internal "switching" device inside of them. 99% sure that is your problem. Bad solenoid.