MPI wiring harness plug ?s
12-11-2017 | 09:56 PM
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MPI wiring harness plug ?s
Wiring up my two wiring harness for LS engines to be plug and play ready for any Merc MPI 502 etc
Pin#4 to the alarm buzzer, does anyone have diagram or know how that circuit is done? Is the alarm always fed 12v power and the ecu gives it ground to turn buzzer on, or is it vice versa? Most ecu switch ground.
Pin#6 looks like this is the constant power feed up to all the gauges etc so from the hull/engine harness connector should be ran in something like 10 gauge direct to battery power
Pin#9 the data line... where is this normally going to from the engine side of the plug going to the hull side of the harness. The diag port Ive always seen on these is built into the engine side of the harness. If that wire is going forward of the forward bilge bulkhead somewhere or better yet to the dash that would be assume, I could bring in my OBDII to this wire, splice it somwhere near the cockpit of the boat to a OBD port, feed port 12 vols and ground and not have to open hatches to plug into each computer, all using existing wiring. Just not sure where that brown/orange dataline they show with a ring terminal on it would be located??
One of my electric fan outputs Ill likely wire in to turn on the blower heat exchanger pumps on.
Another temp output I may use as an overtemp indicator, when it reaches whatever temp I program it, will send ground trigger that I can tie into the alarm buzzer so if it throws a code OR overheats it will sound, just like Merc stuff
Pretty sure this is the correct plug thats mounted on the MPIs that in the boat now
Pin#4 to the alarm buzzer, does anyone have diagram or know how that circuit is done? Is the alarm always fed 12v power and the ecu gives it ground to turn buzzer on, or is it vice versa? Most ecu switch ground.
Pin#6 looks like this is the constant power feed up to all the gauges etc so from the hull/engine harness connector should be ran in something like 10 gauge direct to battery power
Pin#9 the data line... where is this normally going to from the engine side of the plug going to the hull side of the harness. The diag port Ive always seen on these is built into the engine side of the harness. If that wire is going forward of the forward bilge bulkhead somewhere or better yet to the dash that would be assume, I could bring in my OBDII to this wire, splice it somwhere near the cockpit of the boat to a OBD port, feed port 12 vols and ground and not have to open hatches to plug into each computer, all using existing wiring. Just not sure where that brown/orange dataline they show with a ring terminal on it would be located??
One of my electric fan outputs Ill likely wire in to turn on the blower heat exchanger pumps on.
Another temp output I may use as an overtemp indicator, when it reaches whatever temp I program it, will send ground trigger that I can tie into the alarm buzzer so if it throws a code OR overheats it will sound, just like Merc stuff
Pretty sure this is the correct plug thats mounted on the MPIs that in the boat now
12-13-2017 | 12:13 AM
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Looks like anything that provides ground to pin#4 will buzz the alarm, its provided 12v from ignition hot circuit at the helm. So the will be grounded if check engine light is requested, oil pressure low, coolant temp high, and maybe drive oil level switch is tied into this too?
6 it looks like needs to go to a fused/circuit breaker feed from battery, Heavy 10 gauge wire that feeds power to everything at the helm
5 is switched power from igntion so that will go out to engine harness to trigger Ign relay.
Pin 9 I believe is just taped up under the helm gauges according to one of the manuals I have?
6 it looks like needs to go to a fused/circuit breaker feed from battery, Heavy 10 gauge wire that feeds power to everything at the helm
5 is switched power from igntion so that will go out to engine harness to trigger Ign relay.
Pin 9 I believe is just taped up under the helm gauges according to one of the manuals I have?
