Power trim goes up, not down

[mercsmp]

I have a 2006 Mercury Optimax 90 HP. The up power trim works, but the down power trim does not. When I press the down power, there is no sound and nothing happens. I swapped the UP relay with the DOWN relay and the symptoms stayed the same.

I bypassed the relays by removing them and jumping the female connector terminals as described below to see if the trim would work. It worked both up and down.

Wire jumper configuration to completely bypass the relays and make the motor trim UP:
On the UP relay, place a jumper between terminals 87 and 30
On the DOWN relay place a jumper between terminals 87A and 30

Wire jumper configuration to completely bypass the relays and make the motor trim DOWN:
On the up relay place a jumper between terminals 87A and 30
On the down relay play a jumper between terminals 87 and 30

Questions:
1. Why did the symptoms stay the same when I swapped the two relays but when I jumped the relays as described above, the trim worked as it should?
2. Does this test prove that at least one of the relays is bad or could it be something to do with the relay connectors or something else?
3. Should I buy two new relays and replace them or are there other tests I need to perform?

 

[111torrance111]

I have a 2006 Mercury Optimax 90 HP. The up power trim works, but the down power trim does not. When I press the down power, there is no sound and nothing happens. I swapped the UP relay with the DOWN relay and the symptoms stayed the same.

I bypassed the relays by removing them and jumping the female connector terminals as described below to see if the trim would work. It worked both up and down.

Wire jumper configuration to completely bypass the relays and make the motor trim UP:
On the UP relay, place a jumper between terminals 87 and 30
On the DOWN relay place a jumper between terminals 87A and 30

Wire jumper configuration to completely bypass the relays and make the motor trim DOWN:
On the up relay place a jumper between terminals 87A and 30
On the down relay play a jumper between terminals 87 and 30

Questions:
1. Why did the symptoms stay the same when I swapped the two relays but when I jumped the relays as described above, the trim worked as it should?
2. Does this test prove that at least one of the relays is bad or could it be something to do with the relay connectors or something else?
3. Should I buy two new relays and replace them or are there other tests I need to perform?

Based on your test it shows both relays worked, look into the switch that makes it go down. Again your test also shows the pump worked based on your work around. Got to be either the switch or possibly another solenoid inline with the relay.

 

[Chris1956]

Make sure the ground wires on the up relay are clean and well connected to ground. When you command the trim down, ground is supplied to the up (blue) wire of the trim motor by the not energized relay.