johndezman
Petty Officer 2nd Class
- Joined
- Oct 22, 2001
- Messages
- 127
I'm in the middle of a project that is rapidly becoming a nightmare.....
Situation is a 1993 formula 31 pc that shipped from factory with twin 454 mercruisers and at some point, had those 454's replaced with 502's.
after having those 502's rebuilt, and digging deeper into what was needed to be sea worthy we find that a
the temp gauges don't work and b the alternators are not being excited as there is less than 12 volts on that lead (voltmeter reads 10 volts).
further investigation has revealed that the harness has been canibalized at some point (presumably with the 454 to 502 switch) in that the main power and ground do not go through the large plug in harness. also some color codes "change" across the plug.
Yes I have wiring diagrams coming.
My questions are:
1.) is there any reason to believe there was a need to rewire a 502 (versus the 454 scheme)?
2.) are there any physical changes to the harness from mercruiser 454 vs 502?
3.) what are the chances that a simply inadequate ground would cause both the temp gauges and alternator malfunction?
Situation is a 1993 formula 31 pc that shipped from factory with twin 454 mercruisers and at some point, had those 454's replaced with 502's.
after having those 502's rebuilt, and digging deeper into what was needed to be sea worthy we find that a
the temp gauges don't work and b the alternators are not being excited as there is less than 12 volts on that lead (voltmeter reads 10 volts).further investigation has revealed that the harness has been canibalized at some point (presumably with the 454 to 502 switch) in that the main power and ground do not go through the large plug in harness. also some color codes "change" across the plug.
Yes I have wiring diagrams coming.
My questions are:
1.) is there any reason to believe there was a need to rewire a 502 (versus the 454 scheme)?
2.) are there any physical changes to the harness from mercruiser 454 vs 502?
3.) what are the chances that a simply inadequate ground would cause both the temp gauges and alternator malfunction?
