1974 evinrude 70 trim/tilt wiring diagram

[crazy_cowboy_01]

Hi guys.

I have a 1974 evinrude 70 hp with a trim and tilt option. My calco pump had burnt out so I bought this replacement on ebay. It is an omc 980940 pump. Here is a picture of it.

this pump has the same mounting holes and will fit in the same place the calco did and it looks like a prestolite pump. I notice this pump has only 2 wires and 2 solenoids. with the casing grounded, and power to either wire the pump runs in both directions. so this makes it a 2 wire pump? or is it a 3 wire pump with 2 wires and a ground to the body?

I have seen wiring diagrams for a 3 wire pump with one solenoid for the up side. like this.

so is this pump wired the same way but with 2 solenoids?

how did omc wire them back in the day? I know the solenoids are stock and not added on by someone, and they are 3 pole solenoids with a grounded base.

so how do I wire my 2 wire pump with case ground with 2 solenoids?

 

[mfkadz]

My thought on the single solenoid goes like this....

It takes more current to raise the motor than to lower it. Gravity helps it go down. By using the solenoid on the up the current runs through the solenoid instead of the switch. This is the same principle as headlights. Back in the day all the current went through the switch. This caused switch failures. Also, higher current ran to the dash and back. By placing the solenoids under the hood the current runs a shorter path and you do not need a high current switch.

Dual is better for the switch.

Something is up with photobucket. I will fix the pic if it is not right when PB is working again.

http://i296.photobucket.com/albums/...6-FEFA-4FE3-A5C2-45A7A1A1352F_zpsthdlm6fy.jpg

Mike