m998 Solenoid Wire ( 74A ) Hot All The Time

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knighthawk

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I have a 1986 M998 that the starter solenoid burned out on. I replaced the solenoid and starter with a good used unit. When I hooked the batteries back up the starter engages and tries to start the engine. The problem is that wire ( 74A ) to the starter solenoid is hot all the time the batteries are hooked up even with the ignition switch in the off position. The ignition switch is working correctly ( tried a spare with the same results). At this point I suspect the power control box but I do not have a spare to try. Am I missing something or should I go ahead and order a replacement PCB ? M998 with a 6.5 and 200 amp alternator if it makes a difference.
 

knighthawk

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No it is the stock ignition switch. Wire 11A is hot with the batteries connected. 29A gets power when switched to run and 14A gets power when switched to start. Checked with a meter and verified by changing out switches.
 

86humv

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Ign. switch out "S" should be 14A to Neutral sw.In...then Neutral out should be 14B to Smart start in socket "A".
Smart start out in eng. compartment is Pin " I " to wire 74A to solenoid.
......................
Disconnect batteries, ...unplug under dash connector on Smart box.
Then reconnect batteries.....and with Ign, sw. off...check socket A on dis-connected harness.....should be no voltage until you turn Ign. sw to start [ with neutral sw. on shifter engaged.
 

knighthawk

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86humv, Per your suggestion I checked the dash connector on the smart box. I have no power to socket A in any position , i.e. no voltage in the off, run , or start positions.
 

86humv

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86humv, Per your suggestion I checked the dash connector on the smart box. I have no power to socket A in any position , i.e. no voltage in the off, run , or start positions.
Make sure your shifter is in neutral.
If nothing.....You can also disconnect it under truck and see if your getting voltage to the switch.
 
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