Fuel pump no power
#52
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Joined: Nov 2009
Posts: 4,198
Likes: 500
From: KY
This is maybe what is going on. I'm thinking your new harness is for a 3 and your ECM is a 1.
That said, I took my 1 harness, and did plug it into one side, very gently into my 3 ECM. Don't have a 3 harness other then whats on the boat and not going to try with it on the 1 to verify
I also compared my mefi 1 and 2 spare ECM's and the pin out looks the same (32 pin connectors). So if your harness is missing keys which keep a 1 from plugging in, then it would happen without knowing with my limited knowledge
That said, I took my 1 harness, and did plug it into one side, very gently into my 3 ECM. Don't have a 3 harness other then whats on the boat and not going to try with it on the 1 to verify
I also compared my mefi 1 and 2 spare ECM's and the pin out looks the same (32 pin connectors). So if your harness is missing keys which keep a 1 from plugging in, then it would happen without knowing with my limited knowledge
#53
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Joined: Jun 2015
Posts: 77
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From: Charlotte
From my research which is talking several marine tuners it is possible to “ go from 1 to 4 and 4 to 1.
Basically going from 3 to 1 would require changing the knock sensor and FPR pins and connector. I still have my old harness which should make things easier.
Basically going from 3 to 1 would require changing the knock sensor and FPR pins and connector. I still have my old harness which should make things easier.
#54
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Joined: Jul 2011
Posts: 9,594
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From: Ft. Worth TX
Hard to comment in great lengths but for a jist MEFI 1 does not even have the same circuits pin outs nor the J connectors per those compared to MEFI 3.
This is how the ecm can surely be can end up being damaged and I still do not see how you connected the ecm from a mefi 3 harness to mefi 1 and the engine starts and runs ???
HERE IS PRIME example how off base this is for just example.
THE IAC for mefi 1 and MEFI 2 is J2 - 28 and J2 - 13 and J2 - 14 and J2 - 29
The IAC for MEFI 3 is J1 - 28 and J1- 12 and J1-11 and J1 - 27 not even close for connections and pin outs in the ECM for jist of an example.
Do you have a service manual for this per what you are trying to do ?
This is how the ecm can surely be can end up being damaged and I still do not see how you connected the ecm from a mefi 3 harness to mefi 1 and the engine starts and runs ???
HERE IS PRIME example how off base this is for just example.
THE IAC for mefi 1 and MEFI 2 is J2 - 28 and J2 - 13 and J2 - 14 and J2 - 29
The IAC for MEFI 3 is J1 - 28 and J1- 12 and J1-11 and J1 - 27 not even close for connections and pin outs in the ECM for jist of an example.
Do you have a service manual for this per what you are trying to do ?
Last edited by BUP; 04-30-2020 at 08:21 PM.
#55
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Joined: Jun 2015
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From: Charlotte
Bup
You are way more knowledgeable than I am. All I did was call a few tuners and the tuner at AZ speed told me he would sell me a diagram on what pins to change to use the Mefi 1 ecm.
Another tuner Hardin Marine suggested not doing that.
All Dodge is willing to send me a mefi 1 harness if that was your 2 best choices Which way would you go?
You are way more knowledgeable than I am. All I did was call a few tuners and the tuner at AZ speed told me he would sell me a diagram on what pins to change to use the Mefi 1 ecm.
Another tuner Hardin Marine suggested not doing that.
All Dodge is willing to send me a mefi 1 harness if that was your 2 best choices Which way would you go?



