2008 Bayliner 185 4.3 TKS Blows 20A Ignition Fuse

[jjmerc43]

Greetings, I have a 2008 Bayliner 185 that is blowing the 20A ignition Fuse (Fuse # 14:, Red/purple and red/white wire) when the boat goes on plane. Cold start is fine.
If I change the fuse, the boat will start when cold, but once it goes on plane, the fuse will blow.

Details:
Model: MCM 4.3 Litre
Engine Serial: 1A063953
Merc 4.3 Litre TKS
Fuse #14 is blowing, left of the Carb

Does anyone have a wiring diagram available or troubleshooting tips? I'm handy with a multimeter. If I take the power going to the blower motor switch and move it to the ignition switch, the boat runs fine.

Thanks in advance,
John

 

[jjmerc43]

Greetings, I have a 2008 Bayliner 185 that is blowing the 20A ignition Fuse (Fuse # 14:, Red/purple and red/white wire) when the boat goes on plane. Cold start is fine.
If I change the fuse, the boat will start when cold, but once it goes on plane, the fuse will blow.

Details:
Model: MCM 4.3 Litre
Engine Serial: 1A063953
Merc 4.3 Litre TKS
Fuse #14 is blowing, left of the Carb

Does anyone have a wiring diagram available or troubleshooting tips? I'm handy with a multimeter. If I take the power going to the blower motor switch and move it to the ignition switch, the boat runs fine.

Thanks in advance,
John

Picture of 20A fuse

 

[jjmerc43]

Picture of 20A fuse

 

[jjmerc43]

Solved: I bought the factory service manual, the fuse in the picture above is for the TKS system. The actual 20A ignition fuse on my boat was closer to the distributor. Changed fuse, got power back. Now for the root cause, changed TKS temp switch and diode. At first I changed the TKS temp switch, and the engine started fine, but once warm it would not shut off due to the faulty diode. As other have mentioned, I purchased a set of IN5404 diodes and made a holder out of a mini fuse box. Works perfect. You can close this thread as resolved. Take care everyone.

 

[nola mike]

nice, thanks for the update. usually people are all over tks problems here, looks like you slipped through the cracks...

 

[alldodge]

Wish I would have noticed this thread sooner, could have saved you some time