Honda BF20 Blowing Fuses

Hello everyone, new o the site. Ive been searching everywhere for an answer and found this great site. So I purchased a 2008 BF20 this year and it runs like a top. Previous owner did not use the tilt/trim electric start function. When I hooked it up to a brand new battery, nothing happened. No turning over, no tilt. Checked the fuse under the cowling and it was blown. Replaced it and hooked the battery back up, immediately popped the fuse again when the cable hit the terminal. When under power, the tilt/trim works at low rpm. I'm assuming the tilt/trim motor is feeding off of the charging system/rectifier. Has anyone ever experienced this or have any idea whats going on? We did bypass the fuse and the motor turned over so its somewhere between the tiller handle and the fuse block.

Thanks for your help,

Jon

I do not have a specific answer to your problem....but I do have a few suggestions.

1. Don't be mad....but be sure that you are connecting the battery up positive to positive...negative to negative. Reversing the battery will pop the fuse as you describe.

2. The fuse size should be 20 amp.

3. If all that is in order....put a 12 v test light across the fuse holder contacts and connect the battery again. The test light should light if the short is still there. Leave the test light in the fuse holder for testing. That way, will not blow any more fuses and will not fry anything. One thing....do not bother trying to start the engine or to operate the trim and tilt with the test light in the circuit. They will not work.

4. Check the wiring diagram at the end of this manual http://cdn.powerequipment.honda.com/marine/pdf/manuals/31ZY0608.pdf
I know the manual is for a 2006, but the 2008 owner's manual does not have wiring diagrams. The wiring has not changed.

5. The fuse is in a white lead. As you can see, one of the places that the white lead goes to is the regulator/rectifier. Disconnect the white lead going to the reg/rect. Just pull apart the bullet connectors. If the light goes out, follow the lead to the reg/rect to be sure that it is not pinched shorting it to ground. If it goes directly to the reg/rect, you need a new reg/rect.

6. If the light stays on, the white lead also goes to a white/black lead that goes to the trim switch. Disconnect the white/black bullet connector and see if the light goes out. If so, then the white/black is pinched to ground or maybe even shorted to ground around the switch.

7. If the light stays on still, then go back and trace the white lead in the harness from the fuse holder....look for the wiring being pinched or insulation melted to cause it to be shorted to a ground or insulation melted to a black ground lead.

If the problem is not your reg/rect, you may not find a hard short, since you did not say anything about smoke when you bypassed the fuse. In other words...the short is enough to blow the fuse, but it may have some resistance and allow the other circuits to operate as they should.

The good news is.....that the short is there all the time. If should just take a little patience to follow the leads. You may have to cut open the wrapping around the wiring harness leads to follow the wires.

When you get to the point where everything is connected and the light does not light, then you are good to go.

Mike

You da man, thank you for the step by step. I will dive into it this weekend and will follow up with what I find.