1986 C10 intermittent starting issue

[chevymotocross]

Friend's 86 c10 305 has come up with an intermittent starting problem. He went out to start the truck the other day and nothing, no click from the starter or anything. His battery was weak prior to this so he ended up replacing battery. No luck with that.

He had starter tested at the parts store and it came up bad (I wish he came to me first since I would have saved him this expense by jumping the starter). He bought a new starter and sure enough still no start.

I checked it out. All his connections at the starter are tight, there are no burns, cuts, or corrosion. I jumped with a screwdriver from S terminal to battery terminal and it started up.

I went to the neutral safety switch and disconnected the connector there and reconnected it. Started up this time with key. I thought we had fixed the problem thinking maybe there was some corrosion or something. Later on that day he once again had a no-start issue at a gas station but was able to jump the starter with a screwdriver to get home.

Got it home, shut it off, truck restarts. So obviously it is intermittent. It is also not a heat-related issue since it wasn't starting when I checked it out and the truck was stone-cold. It wouldn't start at the gas station with the engine bay hot.

So I am narrowing this down to the NSS or ignition switch. When the truck won't start, the choke light doesn't come on and the fuel gauge didn't rise up at the gas station for him. I'm thinking because his choke light refuses to work at the no-start situations, and when his gauge didn't spike up during that time, it must not be the NSS but the ignition switch?

Here is where I got confused. While the truck WASN'T acting up and when the truck was off, I disconnected the NSS connector, the truck will still start up without that connector connected.... why is that?

Am I on the right track here? How difficult is it to replace that ignition switch? I am assuming the column has to be dropped. It is a non-tilt column.

[old Rusty C10]

ignition switch bottom of the column it bolts on with a couple of small screws

[patrickth]

Originally Posted by chevymotocross

Friend's 86 c10 305 has come up with an intermittent starting problem. He went out to start the truck the other day and nothing, no click from the starter or anything. His battery was weak prior to this so he ended up replacing battery. No luck with that.
?

Am I on the right track here? How difficult is it to replace that ignition switch? I am assuming the column has to be dropped. It is a non-tilt column.

Ignition switch is the easiest thing on the truck. But are you talking switch or key/lock combo. Totally different thing. Does buzzer come on when you insert key?

Jiggle wires to switch, see if thet fixes it when its in a non start mode. If so, thats your problem.

[donut]

IMO, truck shouldn't have started without the NSS connected. There is something shorted, least that's the direction I'd look.

[chevymotocross]

Originally Posted by patrickth

Ignition switch is the easiest thing on the truck. But are you talking switch or key/lock combo. Totally different thing. Does buzzer come on when you insert key?

Jiggle wires to switch, see if thet fixes it when its in a non start mode. If so, thats your problem.

The switch

[motornut]

if the switch is out of wack it won't start
my old camero had to turn the collar back by hand to start
but that was a floor shifter

[chevymotocross]

Originally Posted by donut

IMO, truck shouldn't have started without the NSS connected. There is something shorted, least that's the direction I'd look.

I agree, but after taking a look at photos of new NSS for this truck, it appears there are two connections on the switch? I only noticed one connector which was very easy to see and remove. I'm wondering if that was just for the backup lights?

[Dalaigh]

I had this problem a year ago with my truck, it ended up being the ignition switch on the column under the dash, and my starter was bad. I replaced the ignition switch first and the truck was good for a week or two, then the problem started again. I didn't test the starter, instead just replaced it, and it hasn't been a problem since. Sometimes these old trucks will double up the issues just to through you off.

Replace the switch and check all the related wiring and it should fire right up.

[chevymotocross]

Thanks Dalaigh!