Amp draw 1990 Johnson tilt/trim unit

[Mouse1]

Adapted a '90 Johnson tilt unit to a '72 Johnson 125HP. Have a Johnson relay box, need to know power draw to properly fuse the system.

Thanks.

 

[Joe Reeves]

Depends on where you're taking the voltage from...... if from the ignition switch, it would already be fused via the 20 amp power fuse located a short distance in one of the small red wires connected to the starter solenoid. If taken directly off of the battery at some point, use a 20 ampere fuse.

No, I have no idea what amperage the PTT motor draws... BUT... if it blows that 20 amp fuse, you have a problem!

 

[racerone]

Just curious----Any pictures of parts used and how they are installed ?

 

[Fed]

Only the control circuit is fused via the 20A fuse, the pump motor itself is not fused at all.

 

[Joe Reeves]

Only the control circuit is fused via the 20A fuse, the pump motor itself is not fused at all.

Yeah, I was aware of that, but since this is a conversion, I figured from his explanation he would prefer the safety feature of fusing it.

 

[jimmbo]

Adapted a '90 Johnson tilt unit to a '72 Johnson 125HP. Have a Johnson relay box, need to know power draw to properly fuse the system.

Thanks.

I too am curious as to how it was done. Any pictures?

 

[Mouse1]

Thank you for the responses. Power will be from the battery via selector switch. Going to fuse that line, protect the whole system.
Pics to follow.

 

[Fed]

Fuse the T&T control circuit via the existing fuse and connect the T&T motor circuit to the battery positive side of the starter motor solenoid mouse.
Leave the 'whole outboard' connected directly to the battery just like Millions of other happy boat owners.

 

[Mouse1]

Sorry for the delay, holidays. Here are the pics of the mod. The motor is a '72 125HP the tilt unit from a '90 90HP.

Pic 1, the blue is the original mount. Orange is the lower trim mount point. Block between is 6061 aluminum, shaped and tapped.
Pic 2, is where material was removed to clear steering section,
Pic 3, what was removed, was across the front of motor.
Pic 4, top holes were wider approx. 1/16th " for narrower top mounting holes on motor.

 

[Chris1956]

If you have an accurate ohmmeter, you can figure it out using Ohm's law. I = V/R, where I is current, V is voltage (12 VDC) and R is the resistance of the motor.

Let's say the resistance is 1 ohm. That means 12VDC / 1 ohm is the amperage or 12A. !/2 ohm resistance gives 24 Amps, 1/4 ohm gives. 48 Amps current.

You could also measure the gauge of the motor supply wires and look up the maximum amperage for that size.