Engine and Trim Tilt Issue - ? coincidence

Once I had the engine running as per previous post, I started looking into the tilt/trim issue on my 1986/87 V6 150.

I found some rotten old wiring and broken pins in the 5 wire connector. On trying to replace this, due to very cold weather 2 wires slipped out of my hand and touched. There was a small bang then engine won't even turn over now. I can't figure out how tilt/trim wires caused the starter inline fuse to blow though!

On checking the wiring I found the blown 15mm 20A fuse (which I cannot source anywhere to replace, so have replaced whole housing with a more standard 30mm fuse holder). I can also see a wire going from the starter solenoid to the junction box for the Trim/Tilt power (non fused version). Could it be the solenoid is shot? I tried jumping the starter motor and it sparked like hell but turned over, which leads me to think solenoid. Or am I barking up the wrong tree?

Is there any way I can "jump" the tilt/trim motor - ie connecting the green/blue wires direct power supply to check soundness. Or cut my losses and take to a professional?

Again any advice much appreciated.

Unplug PTT electric motor at its plastic connector. Apply small jumper wires directly from the battery source to the blue and green electric motor wires. The motor will run in one direction... reversing the wires will make the electric motor run in the opposite direction.

Install a normal length 20amp fuse in place of that 30 amp fuse. Since you've changed to a normal length box (approx 1") think accordingly. The 30 amp fuse may give you a problem down the road.

Does the starter solenoid click when you turn the key? If not, check the wiring circuit. With the key in the START position, the voltage circuit would be:

Battery negative cable to powerhead ground.
Battery positive cable to one of the large terminals of the starter solenoid. (12v present always)
12v present at the "B" terminal of the ignition switch. (12v present always)
Starter electric motor cable from other large solenoid terminal to starter.
Small black ground wire from one of the small solenoid terminals to a powerhead ground.
12v present at the "S" (solenoid) terminals of the ignition switch. (key in start position)
12v from "S" terminal to be present at the other small solenoid terminal. (key in start position)
12v to other large terminal of starter solenoid (starter motor). (key in start position)

This would cause 12v to engage the starter solenoid resulting in the voltage to flow within the solenoid via the internal plunger from the large terminal containing the positive battery cable to the other large terminal containing the cable attached to the electric starter.

Thanks for the prompt excellent reply. That was a typo - the fuse is a standard 20mm 20A fuse. Sorry about that!
Must say it's very frustrating - one step forward 10 steps back at the moment!

I may be showing my ignorance here but where is the negative wire to the motor?

For the starter solenoid I will have to wait until I get another pair of hands/ears - blowing a gale and the engine is about 12feet away from the igniton key - can't hear anything let alone see a voltmeter!!

There is no " negative " wire on the starter motor or on the trim motor.

Ok - that settles it then - connecting the blue and green directly to a live battery. Nothing happens. Trim motor is therefore shot.

Dylan Pritchard said:

I may be showing my ignorance here but where is the negative wire to the motor?

Click to expand...

NOTE.... Aways a good idea to specify which motor.... outboard, starter, trim?

If you're speaking of the two wire (green/blue) tilt/trim electric motor, positive voltage is applied to either one of the wires and the remaining wire will be considered ground. This type electric motor is called a dual polarity electric motor.