1986 evinrude 70 hp p trim issue

[maineiac5586]

I'm working on a 1986 70 hp 3 cylinder. Issue is trim won't work when the 2 wire connector is connected (the connector from the relays to the trim motor. I just get clicks from the relay. If I disconnect the plug I can get trim to work when applying voltage directly to the trim motor wires. I have 12 v at the 2 wire connector from the relays when activating trim switch (12 v in up and down positions but only if not connected to the trim motor wires. I checked the voltage at the wires when the connector was plugged in but only getting 8 v or so (on the wires coming out of connector leading to trim motor.) Thinking I was having a bad connection I cut the connector off and wired the trim motor directly to the blue and green wires coming from the relays but the issue still presented itself (relays just buzzing and only 8v or so). My battery is fully charged and cranks the engine fine. I tried 2 new relays but still no dice. Hopefully someone can help me

 

[Crosbyman]

so trim motor sounds ok by itself 2 new relays should be good
12volt comes out OK when no load is applied (the trim motor)

buzzing relays can mean not enough volts/amps to energize the relay coils
properly and the fact the outpout volts drop significantly seems to indicate
a poor power source .

any oxydation (loose or poor connection) will create a resistive path for the current flow to reach the trim motor.

see if you can trace the battery sources to the trim relays ( one may be fused so check fuse contacts)

the other the main 12V trim motor poer suplly may also be in need of a good clean up at junction points .

check all grounds

 

[maineiac5586]

so trim motor sounds ok by itself 2 new relays should be good
12volt comes out OK when no load is applied (the trim motor)

buzzing relays can mean not enough volts/amps to energize the relay coils
properly and the fact the outpout volts drop significantly seems to indicate
a poor power source .

any oxydation (loose or poor connection) will create a resistive path for the current flow to reach the trim motor.

see if you can trace the battery sources to the trim relays ( one may be fused so check fuse contacts)

the other the main 12V trim motor poer suplly may also be in need of a good clean up at junction points .

check all grounds

Ok I'll check into all that. Thanks so far

 

[maineiac5586]

Got it. Ground wire from relays corroded. Cleaned it up all good now. Thank you

 

[Crosbyman]

great news... thanks for your feeedback on the cause