Thread: 87 no crank
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Old 09-27-2018, 03:37 PM   #1
cerial
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Join Date: Mar 2014
Location: Ionia, MI
Posts: 199
87 no crank

1987 V10(4wd) 5.7 700r4
Truck would not crank today

I played around with the starter ignition switch(neutral safety switch) wiring was the issue.

I pulled the connections and found the blue wire was being pushed up so I pushed it down against the switch blade terminal, turned the key, and the truck started.

Shifted the thing from park to overdrive then back to park and then started it again.

The check engine light would come on then go out before I started it. Starter cranks strong and I have 2 1000 amp batteries connected together for 12 volts at 2000 cca.






Not wanting to be shut down for the loose wire. I pulled it and zip tied it the two wires back together then pushed it back in the switch making sure the terminals hit and the truck would not start.




Pulled the thing again and went out buying a new switch thinking it may be the contacts.

I plugged in the connections to the new switch off the column moving it where park should be and the thing will still not crank. Adjusted it around and moved it and still nothing.





Plastic part so I should be able to just set it into the park position having the thing hit the contacts, turn the key, and have the thing fire up. But still nothing there.

But curious if having the thing on the column does anything I installed it into the column and shifted it around before putting the thing into park and still nothing.


I think the orange/black and black/white should be a ground for the ecm.

I think the green and blue are just for the backup lights.


When I turn the key I get the service engine soon light and the break light coming on and no cranking.

I have power to the accessory terminal and to the backup light terminal when I turn the key to the on position.


Key on hot items grounded with test light





Key to accessory



Key to start with switch wired



When switch is not wired the service engine soon light does not come on just the break light lights up.








I want to install a floor shifter for the 700r4 and if possible BYPASS this switch all together.

I installed different taillights so do not have reverse lights currently. I have no problem putting them on a toggle switch.



I have a black/white, orange/black, wire on one plastic connection which goes to the ECM I believe.

Blue and green of the other connection which I believe just controls the back up lights.


But when trying to bypass the switch by connecting the orange/black and black/orange with a jumper wire the thing does not do anything different then when the switch is in place.



Kind of driving me nuts here.
Help please.
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1991 Metro commuter
1991 s10 future project truck
1987 V10 backup daily/junk truck
1985 K20 Winter beater
1991 R30(squarebody) c/c flatbed towrig
1994 s10 80"wb custom build
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