06 Q6 TKS fuse and diode

[maddog2112]

This happened to me year before last as well. My 06 Q6 with 5.0 merc has the TKS carb system. It has always worked as advertised until year before last, when the boat started surging on the lake when I would open it up and eventually shutoff. It would restart after a couple of tries and limp back to the marina. Anyone interested can see my previous posts. Last week she did it again. I checked the 20 Amp fuse on the starboard side of the intake manifold and she was blown. So was the red diode. The diode would pass current both ways. The new fuse and diode fixed this problem two years ago and I`m sure it will again as I have confirmed they are both blown. Does anyone out there know why the fuse and diode blow? Other than that, the boat runs and operated perfectly. No other symptoms, and I do maintain her religously. Has anyone out there had this happen to them?

 

[Fun Times]

While Mercuiser knows of the problem they really didn't say why the problem shows up every so often like this.

The TKS heater module does get pretty warm so maybe it's a heat issue or possibly a voltage spike could be the culprit too.

This might also be a good question for Mercruiser Customer service to see if they happen to now know why it keeps blowing out on you. Using your engine serial number in the following link, try sending them this question to see if maybe they happen to have a better understanding now as to why vs what they said before within Mercruiser service bulletin number 2006-04 tks diode which was

Under some conditions the blocking diode in the electrical system can fail.

https://www.mercurymarine.com/en/us/contact/mercruiser-customer-assistance

Be sure to let them know that you are aware of SB 2006-04 and was hoping for extra feedback as to possibly help reduce the failure rate and the need to keep extras on board with you.
It might not get you anywhere but at least you gave it a try as you never know.

https://yanmarshop.com/catalog/media/F53DEL3GOJSW4Y3INVQXE2LOMUXW2ZLENFQS6YTNMUXUOQKZIRBVQQSRI5JE6RCFJVBFCR22J5CUWVCTG5DUCMSBFZYGIZQ

 

[maddog2112]

Thanks for the reply, Fun Times. I will send Mercury a request and share any info received.

 

[maddog2112]

Fyi. I haven`t heard back from Mercury yet, but same as last time, the boat ran fine this weekend with a new 20A fuse and diode.