MoTeC Global Forum

I'm wiring an M150 for a 4cyl application where an M130 would suffice in terms of outputs, the M150 is only required for additional AV and UDIG inputs.

In this application I don't required the maximum current carrying capacity of all of the 3 battery power connections and 5 battery negative connections connected with 18 AWG wire.

I remember reading that the BAT_NEG and BAT_POS positions must be connected on M150 connectors A and B in order to use LS/HS outputs on those connectors. I also recal someone mention the BAT_NEG and BAT_POS connections are all bused together internally. Can anyone confirm?


I'm trying to decide whether to:

Connect only the M130 equivalent positions (C_10 C_11 and C_26) using 18 AWG wire giving 14A of supply and 28A of grounding capacity.

or

Connect all 5 BAT_NEG and 3 BAT_POS locations on the M150 using 22 AWG wire to give 22A of supply and 37A of grounding capacity.

Hi,

My recommendation is to wire in all of the BATT_POS and BATT_NEG pins when doing the loom. This allows for load sharing over all of the pins, and also provides future proofing of the loom in case of further expansion of the functions used.

BAT_POS, through (ignition key controlled) relay, or "direct¨connection to Battery (=always "ON")?

Normally you want switched power. With race cars, we just use the Master Switch (so more like "always on", except the Master Switch is off when the vehicle doesn't need to be powered up).

A recent street car I did used the stock DME relay, with the ability of the ECU to keep the "power relay" triggered to run fans after the ignition is switched off, or keep the PC connection alive even when the engine stops. The DME relay is triggered by both the ECU and an Ignition switched relay.