Ignition circuit fuses?

wakina

Seaman
Joined
Mar 20, 2011
Messages
72
1996 Mercruiser 5.7 L Bravo 3 with Throttle Body Injection .

The ignition circuit is dead no power in the hot wire from the battery to the battery terminal of the Ignition switch. I have checked and double checked the ground wire connections to the block from the batteries and the battery terminal connections both the + & - terminals and they are good. There is 12.5 volts at the starter, the 50 amp breaker and the slave solenoid but no power to the ignition switch.

The engine cranks good and at normal speed when jumping the large terminals on the slave solenoid. The motor will start and run at normal idle speed, if power is jumpered in to the run terminal of the ignition switch but the motor will not crank with the key while jumpering in power to the battery terminal on the ignition switch. The solinoid terminal on the ignition switch tests at 12+ volts when the key is turned to the start/ignition position and 12+ volts at the run terminal when the key is in the run position. Are there any fuses that could be blown that could be causing this problem. I realize the kill switch could be bad as well as the neutral safety switch but they are out of my league and I wanted to check everything else before the repair shop call is made..
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
42,054
1996 Mercruiser 5.7 L Bravo 3 with Throttle Body Injection .

The ignition circuit is dead no power in the hot wire from the battery to the battery terminal of the Ignition switch. I have checked and double checked the ground wire connections to the block from the batteries and the battery terminal connections both the + & - terminals and they are good. There is 12.5 volts at the starter, the 50 amp breaker and the slave solenoid but no power to the ignition switch.
You have no power to the Red/Purple wire on the key switch. If this is correct then check the 20 amp inline fuse which is inline with the Red/Purple wire under the helm.
 

wakina

Seaman
Joined
Mar 20, 2011
Messages
72
You have no power to the Red/Purple wire on the key switch. If this is correct then check the 20 amp inline fuse which is inline with the Red/Purple wire under the helm.

Thanks for the reply, and that is correct there is no power coming into the switch from the Red/Purple wire. I will check that fuse to see if that is the problem. Will post back once I find out!
 

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,291
correct, check all 3 .the middle one powers the injectors and electric fuel pump, all should be 20A fuses
 
Last edited:

wakina

Seaman
Joined
Mar 20, 2011
Messages
72
I checked the fuses today and the 20A fuse under the helm was blown. I also checked the 3 fuses under the metal lid and they were all ok. Changed the fuse under the helm and now have power to the switch. The switch will sitll not activate the slave solenoid. Hooked up the old solenoid to the wires that are Yellow/Red and Yellow/black that push on the 2 small terminals on the base of the slave solenoid and when I turn the igntion to start it will click but the solenoid will not activate, the new one will not click at all. Is it possible that both solenoids are bad? Or should I look for something else.
 
Last edited:

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
42,054
I checked the fuses today and the 20A fuse under the helm was blown. I also checked the 3 fuses under the metal lid and they were all ok. Changed the fuse under the helm and now have power to the switch. The switch will sitll not activate the slave solenoid. Hooked up the old solenoid to the wires that are Yellow/Red and Yellow/black that push on the 2 small terminals on the base of the slave solenoid and when I turn the igntion to start it will click but the solenoid will not activate, the new one will not click at all. Is it possible that both solenoids are bad? Or should I look for something else.

My guess is you have a bad ground or the neutral safety switch is the issue. Use the new slave and connect a jumper to ground on the Yel/Blk small terminal.
 
Top