How does a Mack MP engine starter work?

How does a Mack MP engine starter work?

All Mack mp engine starters are controlled by the engine ecu. The eecu provides the ground circuit for the starter relay. The purpose for that is to protect the starter from overcranking/overheating. If the eecu sees excessive crank time it shuts off the ground circuit to the starter relay for a minimum of 30 seconds. Mine did the same thing.

What are the electrical switches on a Mack truck?

& BATTERY SWITCHES 1/3 49 CD UREA DOSING SYSTEM 22 NE ADDITIONAL IGN. & BATTERY SWITCHES 2/3 50 DC TRANSMISSION CNTR:4 GENERATION 1/2 23 NF ADDITIONAL IGN. & BATTERY SWITCHES 3/3 51 DD TRANSMISSION CNTR: 4 GENERATION 2/2 24 XA-O DATA LINK / DIAGNOSTICS 1/2 52

Where is the AC key on a Mack truck?

AC-O KEY SW., START & CHARGING 4 GG TRAILER LIGHTING CONTROL 32 AD GROUNDING 5 GH-O INTERIOR LIGHTING 33 AE BATTERY CONFIGURATION 6 GI SNOWPLOW PREP CONNECTOR 34

Where is the wiring diagram index, 12v-mack trucks?

WIRING DIAGRAM INDEX, 12V Engineering Release Notice (ERN) Location Change Description A = Added W = Was D = Deleted Document Release Status D-16194-85 SEE DCN Date Modification Count WIRING DIAGRAM INDEX, 12V NAME DESCRIPTION Page NAME DESCRIPTION Page

Why does my Mack E7 engine not start?

Turns out the ECU is very sensitive to voltage drop. Anything below 11.5 volts and it gets the lack of will to work. Mack have installed a voltage warning light in the dash ( just a little red LED ).

Why does my 94 Mack have no fuel?

94 Mack ch. 613. V max. 400. Just stopped have fuel come on the return line to tank did the filters checked the little fuel solenoid works good. Cracked the injections lines. But no fuel there. Dealer sent me a square block with a solenoid on it for 1200.

What does it mean when your truck won’t start?

So your truck won’t start because it doesn’t have enough power to fully energize the electromagnet inside the starter solenoid. The magnetic field keeps on failing, so the solenoid spring keeps on snapping back. That’s what is making the click-click-click noise you hear.

Why is my MP8 engine not cranking at all?

If the eecu sees excessive crank time it shuts off the ground circuit to the starter relay for a minimum of 30 seconds. Mine did the same thing. Took it to Mack and they pulled the oil temp plug on the driver side of oil pan and cleaned the oil out of it an it started right up.

What causes engine to not turn over with key switch?

ENGINE WILL NOT TURN OVER WITH THE KEY SWITCH NO POWER AT THE STARTER. Many things could cause this issue from blown fuse to bad ignition switch, bad vehicle ecu or engine ecu. You need to check all fuses- ones under center dash panel and inside left side kick panel. Check voltage at starter relay w/key in start position, should be 12+ volts.

Is the ignition switch on on my MP8 truck?

All of the electronics and A/C were still on but the engine had shut down and no alarms. This truck does not do that like the newer ones do. Turned the ignition switch off and back on to fire the truck back up, but the starter will not turn over.

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