1990 350 grounding issue

[Chris Matthews]

Hello, I’m looking for some help here. I pulled the engine out of my ski boat. It’s a 1990, mercruiser 350/5.7. I had it bored .030 over and rebuilt it reusing only the crank, everything else is new. I rebuilt the transom reinstalled the transom plate, and the gimbal bell housing and drive with new bellows and shift cables. Anyways, yesterday I reinstalled the engine and plugged everything up, and now I have no power to the dash, the only thing that works is the power trim because it’s wired straight to a battery. The grounding stud on the port side that holds the flywheel housing as well has the negative cable from the battery connected to it and a small black wire from the engine harness. Still somehow the boat is acting like it has no ground for anything else to work. Where should I start looking? Also I have a perko dual switch but the connections in it are good and both batteries are charged. I also checked for continuity from the ground stud to the battery - and it’s good. The manual wiring diagram looks like it says there is and engine ground stud as well as a flywheel housing ground stud. Thanks, also I don’t know how to add a photo to this post to upload the diagram, it says file is too large?
-chris

 

[alldodge]

Need a voltmeter to start looking.
If you had any kind of a spark when connecting it back up, check the 90amp fuse on the starter post. Its a square looking thing with other wires on it.

There should be about a 10 gauge black wire which comes from the harness for ground.

Did the 10 pin harness go back together clean?

 

[wellcraft-classic210]

Make sure your connections are clean on that gnd wire from the batt -- Did you have a ground wire going to one of the 3 the starboard motor mount bolts-- I ask ask many do,

 

[Chris Matthews]

Hey guys thanks for the help. After tracing it more this afternoon I found that the harness ground wire had been pinched beneath the rear mount when I put the motor back in, so I crimped and heat shrinked it back together and we’re all good. Got it fired up for the first time since the rebuild. Now I’ve just got to get it to idle so I can set base time. As of right now it will die running anything below 2600 RPMs. Carb was rebuilt last year though so I’ve got some more delicacies to contend with

 

[alldodge]

anything below 2600 RPMs

Hope your running without drive installed if Alpha or belt off the raw water pump if Bravo. Running that fast a garden hose can not supply enough water to keep it from being damaged

 

[Chris Matthews]

Hey guys thanks for the help. After tracing it more this afternoon I found that the harness ground wire had been pinched beneath the rear mount when I put the motor back in, so I crimped and heat shrinked it back together and we’re all good. Got it fired up for the first time since the rebuild. Now I’ve just got to get it to idle so I can set base time. As of right now it will die running anything below 2600 RPMs. Carb was rebuilt last year though so I’ve got some more delicacies to contend with

 

[Chris Matthews]

Hope your running without drive installed if Alpha or belt off the raw water pump if Bravo. Running that fast a garden hose can not supply enough water to keep it from being damaged

Yes, it’s an alpha but I have the drive off still, I’ve got an old water hose zip tied to the plastic water pick up tube on the outside of transom running into a bucket full of water.

 

[Bondo]

Yes, it’s an alpha but I have the drive off still, I’ve got an old water hose zip tied to the plastic water pick up tube on the outside of transom running into a bucket full of water.

Huh,..??..??

Plastic water tube,..?? into a bucket of water,..??

You need hose pressure either into the water port on the bellhousin', or into the in-comin' port on the t-stat housin',.....