no power to the purple wire on starter

TurboDave

RIP DAVE
Staff member
TurboBuick.Com Supporter!
May 24, 2001
12,347
382
83
71
Seymour, TN
OK, where is this P/N safety switch? Got pictures?

RemoveBeforeFlight
This is the best I can do, it's crowded up in there. See the white half moon switch on top the column? That's it. The P/N safety switch.



Sent from my iPhone 6+ using Tapatalk.
 

RmvBfrFlght

Well-Known Member
Sep 28, 2007
2,121
151
63
PA
Sorry, but that isn't the P/N safety switch on our Buicks. That is the backup lights and P/N signal to the ECM switch. Dave, it looks like we were posting at the same time, if you missed it see my post just previous to yours above.

RemoveBeforeFlight
 

TurboDave

RIP DAVE
Staff member
TurboBuick.Com Supporter!
May 24, 2001
12,347
382
83
71
Seymour, TN
OK, picture of it with the heavy purple wires going to it? No can do because it isn't there. That switch, as I previously posted, it for the back up lights and P/N signal to the ECM.

From the FSM, see note to right of ignition switch:

View attachment 258363
And, where is the P/N safety switch in the above diagram?

RemoveBeforeFlight
It's right on your diagram above. It's the box near the top incorrectly labeled ignition switch. But that's the device mounted on top the steering column down under the dash that I photo'd.
 

TurboDave

RIP DAVE
Staff member
TurboBuick.Com Supporter!
May 24, 2001
12,347
382
83
71
Seymour, TN
It's right on your diagram above. It's the box near the top incorrectly labeled ignition switch. But that's the device mounted on top the steering column down under the dash that I photo'd.
Correction, I'm looking at the wrong part. I can't find the wiring diagram for the switch I photo'd.
 

TurboDave

RIP DAVE
Staff member
TurboBuick.Com Supporter!
May 24, 2001
12,347
382
83
71
Seymour, TN
Here's some better pictures of what comes up when I google "87 buick neutral safety switch".

switch.jpg
switch1.jpg
 

RmvBfrFlght

Well-Known Member
Sep 28, 2007
2,121
151
63
PA
The left image you posted showing the switch on the column is mine. I posted that here some time ago. Here are two other pictures I took . This first one is from the passenger side and shows the back up light connector. That is the blue & green wires. Note the open area along with the ORG/BLK and BLK/WHT wires on the lower left (P/N to ECM):

GN_PN-SW_6a.jpg


And the wiring diagram for the back up lights, matches the wire colors:

BackupLights.jpg

Then a left side view of the column switch showing the P/N input to the ECM. That is the ORG/BLK wire. When grounded the ECM sees that as in P/N, open the ECM sees that as 'in drive.'

GN_PN-SW_5a.jpg


The green wire behind it is from the backup light connector. Here it is shown on the ECM wiring, although it states that the BLK/WHT wire is tied to the transmission, it is most likely grounded to the dash someplace:

EcmWiring1.jpg



No purple starter P/N safety interrupt wires anywhere on that column switch. The P/N safety is the mechanical blocker built into the column. Try it, place the shifter in the D position and try to crank the engine. As long as that goofy linkage is adjusted properly the key won't turn far enough to crank the starter.

RemoveBeforeFlight
 

RmvBfrFlght

Well-Known Member
Sep 28, 2007
2,121
151
63
PA
I stand corrected. So, it's mistakenly called a P/N safety switch.
Yes to mistakenly called a P/N safety switch. I discovered this shortly after I got my car. The reverse lights didn't work and the P/N input to the ECM was flaky. It would flicker between P/N and drive when shifter was in the P/N position (grounded).

Cars this old, the grease in the column switch is all dried out. Pull it, open, clean, grease, check the operation, uh, wait a minute... If this doesn't have the two heavy purple wires on it, where the heck is the P/N safety switch? Looked at the shifter, nothing there.

Drove me nuts until one day I was looking at the cranking wiring. Read the note, and went :banghead:

RemoveBeforeFlight

P.S. As the reverse lights, there weren't any bulbs in the sockets...