Neutral switch replacement/adjust help needed

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hatzie

Full Access Member
Joined
Dec 6, 2011
Posts
567
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Location
NH
First Name
David
Truck Year
1976
Truck Model
k20
Engine Size
6.5
On the 1987 RV trucks and probably through to 91 (I haven't looked)... the park-neutral portion should have Green/Black (434, ECM B10) and Black (450, ECM Ground) wires on a two-terminal 12015034 Female Packard 56 plug. This switch grounds the Park-Neutral terminal B10 on the ECM allowing engine start.

To avoid people making assumptions...
1973-1986 used a different method. The Neutral safety switch interrupted the CRANK wire from the ignition switch and passed volts to the actual START wire through the neutral safety switch or the clutch interlock switch.
 

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