Key Data: 2005 Mercruiser 3.0L with Alpha drive in Bayliner 175. Failed starting or slave solenoid (OEM # 89-96054T).
Last season I replaced the slave solenoid on my engine and my starting problems went away. This season after doing some major engine work (cracked head
), I was excited to restart my boat in prep for summer. To my dismay, all I heard was a click at the engine. So I pulled out my notes from this brilliant post (http://forums.iboats.com/mercruiser...ting-your-engines-starting-system-167035.html) and starting working my way from bow to stern (i.e. key and back). The problem was quickly evident at the slave solenoid 
- when key was turned to start position, solenoid clicked and no voltage was evident across the larger terminals (however, shorting across the solenoid immediately starts the engine).
So, with all this, I've proven the solenoid is bad...easy you say, replace and getting under way...here is the interesting part.
This solenoid was effectively brand new. I replaced it last season in June, ran the boat for a few weeks and then the head cracked so it's been in storage for nearly 10 months, with no power connected. I thought the odds of two solenoids failing in succession were very low, so decided to pull the old one apart. The contact surface for the "cold" side (i.e. the terminal not connected to the hot 12V) was completely black and corroded. It was effectively so black it was invisible against the black housing. I'm virtually sure the current one will look the same as the symptoms are identical - will be pulling it apart tomorrow.
Here's my question - what could be causing the solenoid to corrode inside on the non-energized contact surface?
Also, I live in smaller town and finding this part is unreasonably expensive. Does anyone know if there is an equivalent automotive part and is there any reason not to buy a couple and swap out if it fails?
Thanks,
Mike
Last season I replaced the slave solenoid on my engine and my starting problems went away. This season after doing some major engine work (cracked head
), I was excited to restart my boat in prep for summer. To my dismay, all I heard was a click at the engine. So I pulled out my notes from this brilliant post (http://forums.iboats.com/mercruiser...ting-your-engines-starting-system-167035.html) and starting working my way from bow to stern (i.e. key and back). The problem was quickly evident at the slave solenoid - when key was turned to start position, solenoid clicked and no voltage was evident across the larger terminals (however, shorting across the solenoid immediately starts the engine).So, with all this, I've proven the solenoid is bad...easy you say, replace and getting under way...here is the interesting part.
This solenoid was effectively brand new. I replaced it last season in June, ran the boat for a few weeks and then the head cracked so it's been in storage for nearly 10 months, with no power connected. I thought the odds of two solenoids failing in succession were very low, so decided to pull the old one apart. The contact surface for the "cold" side (i.e. the terminal not connected to the hot 12V) was completely black and corroded. It was effectively so black it was invisible against the black housing. I'm virtually sure the current one will look the same as the symptoms are identical - will be pulling it apart tomorrow.
Here's my question - what could be causing the solenoid to corrode inside on the non-energized contact surface?
Also, I live in smaller town and finding this part is unreasonably expensive. Does anyone know if there is an equivalent automotive part and is there any reason not to buy a couple and swap out if it fails?
Thanks,
Mike
