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No Juice at Ignition Switch

C

chiefbill

New member
Have twin 2001 Mercruiser 5.7L

Have twin 2001 Mercruiser 5.7L EFIs with Bravo III drives and my problem is that I have no power at my Strbd Ignition Switch. I have checked 50 AMP breaker on engine and it is OK. All wiring at the dash seems to be OK as is the red/yellow neutral wires coming from the shifter. The start up beeper was getting weak before everything died. The port switch works fine. Anyone have any ideas???
 
"w;
Power should be present a

"w;
Power should be present at the key switch B terminal at all times, via a red/pur wire from the 10 pin plug. Check this B terminal for 12 volts. If no joy, you likely have a dirty 10 pin plug at the engine, or bad wiring. Pull the plug apart and check for corrosion.
If the B terminal has 12 volts, check for 12 volts at the I terminal (purple wire) when the key is turned to ON. If no joy, the key switch is bad.
Hope that helps,
Rod"
 
"Had a similar problem on my a

"Had a similar problem on my airboat when I installed a brand new ignition switch (old one had corroded). Wired in the new one, was sure I had it right, and the danged thing just had no power. Turns out the switch was bad, even though it was brand new. A quick swap-out and all was well.
Spent 2 hours longer than I needed to playing with wiring and testers, just not believing the new switch was bad."
 
Thanks to Rod and JPowers for

Thanks to Rod and JPowers for their input. Have checked all terminals on back of key switch and have no juice to any of them. The port switch has power and does work. guess I will try to find the 10 pin plug at the engine and see what shape it is in.
 
"You are looking for the large

"You are looking for the large "barrel" plug on the engine--can't miss it. Have you checked the battery cables for clean connections on both ends? These cables carry alot of current and must be in pristine condition to maximize the voltages needed to run your boat especially since you have EFI which uses very low voltage to operate it.

Get your self a digital voltmeter for about $30. It will tell you a meriad of information about the voltages, drops in voltage (VERY IMPORT.) and condition of electrical parts. It will help you find the problem fast.

The power to your boat starts at the battery, goes to the starter and then to the 50 amp breaker. It branches off before and after it. A major part of troubleshooting is "OBSERVATION"."
 
"w;
My bet is you have a corr

"w;
My bet is you have a corrosion issue at the 10 pin plug. It's the plug that has the major wiring harness running to it usually at the rear of the engine near the stbd side valve cover.

Before you do that you may want to check the terminal on the 50 amp breaker where the red/pur wire connects. It should have +12 volts at all tmes. If not, check the other teminal on the breaker where a heavy red wire connects. If it has 12 volts, the breaker is bad. They fail sometimes.
Rod"
 
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