Author Topic: Ok where is the neutral safety switch on an 86 C10  (Read 47990 times)

Offline notched

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Ok where is the neutral safety switch on an 86 C10
« on: October 28, 2009, 05:35:12 PM »
Yeah I know this is a stupid question but ALL of the older GM vehicles I have ever owned with an automatic trans had the white plastic switch on the column down by the firewall. For some reason mine only has the connections for the back up lights. It doesnt look like it has any other terminals. The shifter linkage was messed up when I got the truck and I got it where it worked well. The back up light position for reverse was off  but that didnt bother me. Well today I had it running and went to start it again and it wouldnt start in park, only in neutral. That is why I am thinking it is probably a neutral safety switch, but for the life of me I cant find it!
Truck is a 350 with a 700r4 trans basically an old work truck so its not like its been messed with.
Am I correct that the wires for the neutral safety switch are usually purple and yellow?

Offline VileZambonie

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Re: Ok where is the neutral safety switch on an 86 C10
« Reply #1 on: October 28, 2009, 05:39:15 PM »
This wasn't converted to an automatic was it?
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Offline VileZambonie

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Re: Ok where is the neutral safety switch on an 86 C10
« Reply #2 on: October 28, 2009, 05:47:10 PM »



C, K, R & V MODELS


Disconnect battery ground cable.
Disconnect electrical connector at switch.
Remove switch mounting screws, then the switch.
Position shift lever in neutral gate notch.
Insert a .098 inch gauge pin into switch gauge hole as shown, Fig. 13, then assemble switch to column by inserting carrier tang into shift tube slot.
Install switch mounting screws into retainers. If retainers strip, they must be replaced.
Remove gauge pin, then position shift lever into Park to shear internal plastic pin in switch.
Return shift lever to neutral gate notch, then ensure switch gauge hole will accept .080 inch gauge pin. If not, loosen mounting screws, then rotate switch on column until .098 inch gauge pin can be reinserted into gauge hole.


Reconnect electrical connector and battery ground cable.
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              ⌠ŻŻŻŻŻ'   [☼===☼]
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74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline notched

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Re: Ok where is the neutral safety switch on an 86 C10
« Reply #3 on: October 28, 2009, 06:17:27 PM »
This wasn't converted to an automatic was it?

Nope. It has always been an automatic. The RPO tag in the glove box also states the correct RPO for the 700r4.
My switch on the column looks like the one in the picture but only has pin's 153 and 154
There are no other pins on it. There are also no wires hanging under the dash. I will crawl under it to see if there is a switch down at the trans.

Offline notched

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Re: Ok where is the neutral safety switch on an 86 C10
« Reply #4 on: October 28, 2009, 06:31:44 PM »
RPO for the trans is MXO. It doesnt look like there were ever any wires going down to the trans except for the 4 pin lock up plug.
Its odd because I had it running and never had issues except for shifter alignment which I fixed and NEVER had a problem starting. Then today out of the blue it wouldnt start in Park. I got it to start in neutral. Now it wont even start in neutral.
Here are some pics


Offline zieg85

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Re: Ok where is the neutral safety switch on an 86 C10
« Reply #5 on: October 28, 2009, 07:41:45 PM »
Unplug that then jumper it.  It should start then and tell you if the switch is bad.
Carl 
1985 C20 Scottsdale 7.4L 4 speed 3.21
1986 C10 under construction
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Offline notched

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Re: Ok where is the neutral safety switch on an 86 C10
« Reply #6 on: October 28, 2009, 09:47:28 PM »
Unplug that then jumper it.  It should start then and tell you if the switch is bad.

Did that already. All that did was turn the back up lamps on.
Im still looking for the neutral safety switch if anyone has any ideas or has seen anything like this.
I am almost thinking it might not have one since the shifter seems to have gates and only allows the ignition switch to move to the crank position in Park or Neutral.

Offline VileZambonie

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Re: Ok where is the neutral safety switch on an 86 C10
« Reply #7 on: October 28, 2009, 09:51:29 PM »
The gate prevents the ignition cylinder from rotating on certain columns unless it's in park or Neutral. On other models it's an adjustment on the nss. Are you saying in park the cylinder will not rotate to the full crank position?
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Offline notched

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Re: Ok where is the neutral safety switch on an 86 C10
« Reply #8 on: October 28, 2009, 10:59:19 PM »
The gate prevents the ignition cylinder from rotating on certain columns unless it's in park or Neutral. On other models it's an adjustment on the nss. Are you saying in park the cylinder will not rotate to the full crank position?

No it will rotate in park. All accessories work. It just wont engage the starter. Like I said earlier it was strange because when it first happened I was able to get it started in neutral. Now it wont start in either spot. I have checked the starter manually with my Matco remote switch and it works fine.
From past experience with other vehicles it acts like a bad or misadjusted neutral safety switch. Its just I cant find the darn thing!  >:(

Offline VileZambonie

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Re: Ok where is the neutral safety switch on an 86 C10
« Reply #9 on: October 29, 2009, 05:03:39 AM »
Put a test light to ground on the S terminal of the starter and have an assistant crank it in park. See if it lights up.
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74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline notched

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Re: Ok where is the neutral safety switch on an 86 C10
« Reply #10 on: October 29, 2009, 06:22:17 PM »
Tested it today. Wire has continuity. Turned out to be a bad ignition switch.
I tested the new switch prior to installing. It will start in any position so that shows the 86 does not have a neutral safety switch.
I was out at a local yard and found an 87 in there and it was the same way. I suppose the ones with a gated shifter dont use/need a neutral safety switch.
Thanks for the help and advice.

Offline kirby1374

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Re: Ok where is the neutral safety switch on an 86 C10
« Reply #11 on: June 20, 2014, 11:44:43 PM »
I know this thread is ancient BUT did he ever figure it out? I as well cannot find any wire on my switch to even plug into the switch even if my switch had terminals.