cmfjay

ok here goes , turn the key oil gen and hot lights come on dash , but no click , doesn't turn over nothing . under the hood , battery is good , connection from bat to neg and pos to started good, can jump the starter for it to turn but that's it. is there a relay between I aint seeing ? is it just a fuse I cant find . wtf scratching my head here !

m371961

Neutral switch?

oldstata

So if you jump the start it starts ?

This sounds like your safety neutral switch

joe_padavano

Let's start with you telling us the year and model, as GM did away with the electric NSS in the late 1970s.

cmfjay

1971 cutlass supreme , 350 5.7

jaunty75

If the car WILL start when connected by jumper cables to a known good battery but won't start without it, why would the problem be the neutral safety switch? I would think a bad NSS would cause a no-start problem regardless of where the current was coming from.


To the OP, how do you know the battery is good?

I had a similar-sounding occurrence with a '90 Ford Taurus. All of a sudden, turn the key and nothing. All lights, radio, etc. came on just fine, but nothing when I turned the key. Called the AAA, he comes over, hooks up jumpers, and the car starts right up. Tows it to a shop, they check the battery, and it had one dead cell. There was still enough voltage to light everything up but not to cause it to crank. New battery fixed it.

joe_padavano

I'm guessing that "jump the starter" means shorting the terminals on the solenoid.

To the O.P. - is the backdrive linkage from the trans to the steering column still in place? The NSS is at the base of the steering column and the backdrive linkage is required, even for a floor shift car.

If the linkage is in place, then the problem is likely a bad or misadjusted NSS. In that case, pull the connector off the NSS that has two purple wires, jumper across them in the connector, and see if it starts.

Octania

Is the car in neutral or park?
If you have floor shift with the backdrive to column mtd NSS, sometimes you have to manually rotate the column collar more counter clockwise in order to place that part "in park" due to slop in the linkage. My '85 won't let the key out unless you "help" the column into "park".

Jumpering across the NSS large purple wires will bypass the NSS for testing purposes.

Depending on what you mean by "jumped the starter," I agree that a dead battery can be the cause. Can you get a helper and check the battery voltage while the key is in the start position? Post to post.... then start taking readings further down the line- on the terminal, not the post. on the cable if possible. Far end of cable. etc.

If the battery reads 12V when not in use, then drops to 4 when key is in START position, that's a dead battery. If the voltage is 12V all the way to the starter end of the cable, the problem is likely elsewhere such as poor ground cable, poor ground from starter to engine, etc.

What was the last thing "fixed" in the starting system?

cmfjay

yes I mean shorting the solenoid , batt was tested show 100 percent. And it is a automatic tranny.

cmfjay

does the car have to be in neutral or park is ok ?

m371961

Park or neutral should allow starting. WITH YOUR FOOT ON THE BRAKE, try moving shift lever when trying to start. If you find a position the starter runs in, the switch needs adjustment. If not, as stated above the switch can be bypassed to test.

joe_padavano

Is the car a column shift, factory floor shift, or original column shift converted to floor shift?

cmfjay

ok so you a genius , , I found the 2 purple wiers under the dash . they are not plugger into the nss. I took I wire and ran it into the 2 female connections and walla ! will start now , however they are four empty male connections on the nss ! how and where does the female plug into ? hey thanks for the help . you guys are walking me through this pretty well ! by the way its been bugging me for days and iwas up at 3 am screwing with it today ! in the dark with flashlight . DRIVING ME CRAZY !

MDchanic

The NSS plug should only plug in one way. The other two terminals are for the backup lights.

- Eric

cmfjay

FOUND IT ! HEY THANKS FOR THE HELP ! I am positive I will have lots and lots of other questions in the near future . I will post some pics of my progress . THANKS TO MD , JOE AND ALL WITH ANSWERS ! I have a rats nest of wiers under the dash I am woring on along with doing interior and engine lots of work ahead ! thanks again !

Northern Custom Cruiser

Hey long time no post, i got locked put of my account for some time but im back with bad news. Im suffering the same issues cmfjay was up until the purple wires. They were plugged in and when jumpered together the car still wont start.

This is on the 73 delta 88, column shift, 350

The last thing "fixed" was the steering column, i replaced the old and rebuilt a new one which was a pain, if i short the starter solenoid it starts but thats the only way. Replaced the starter and then put the old back on after returning the new only to figure out the shorting trick at 11pm on the side of the highway. Was a fun day.

So whats going on? Ignition switch or something?

Northern Custom Cruiser

It started on and off intermittently and now wont at all by the way unless i jumper the starter

oldcutlass

You need to see if you have voltage at the neutral safety switch when the key is turned to the start position.

MDchanic

Also, conversely, see whether applying voltage to the purple wire that goes from the NSS to the starter cranks the engine.

- Eric

Northern Custom Cruiser

Dumb question, but which wire is to the starter? I touched the two purple wires together but nothing happened

MDchanic

Turn off the ignition switch.

Take a length of 14 or 12 gauge wire, connect one end to a good (+), and touch the other end to each of the purple wires.

The one that makes the starter turn is it.

If neither one makes the starter turn, then you know that the wire to the starter solenoid S terminal is interrupted between the NSS and the solenoid.

- Eric

Northern Custom Cruiser

So if one of the cables makes the starter start then its the NSS? Because that is the case

MDchanic

First, if you don't have a Chassis Service Manual with a color wiring schematic, you should.

A manual or diagram from a different (nearby) year will often help in a pinch.

Here's the '70 A-body schematic:



You can see that the purple wire goes from the START output of the ignition switch, through the NSS, to the S terminal of the starter solenoid.

If the NSS is disconnected and the ignition switch is off, then connecting one side to a hot wire will crank the starter, while connecting it to the other side will dead-end at the ignition switch.

You've determined that connecting one lead to hot will crank the engine, so you know that that wire, all of its connections through the firewall and the engine compartment, the starter solenoid, and the starter are all good.

So now, if there is +12V at the other purple NSS wire when you turn the ignition switch to START, you know the problem is the NSS.
If there is no voltage, then the problem is in the ignition switch, or in the wires and connections before or after it.

- Eric

Northern Custom Cruiser

So, thanks to your walk through i determined that the problem was the ignition switch, I popped the switch off and tinkered with it manually and got the engine to start. I just moved it alittle closer and like magic everything is normal again!

After 90 dollars of parts i get to return and being broke down on the side of the road for 11 hours all i had to do was move the switch up.... Haha....

MDchanic

Ah ha.

See, it's always something simple.

Glad you got it fixed!

- Eric

oldcutlass

X2 with above

boese1978

Had a 76 Dodge Aspen once, would not start- after towing and struggling, come to find out the shifter on the column was simply not all the way in park.....

MDchanic

Yup, that's a pretty common problem, and a first-line troubleshooting step.

My grandfather's '63 T-bird wouldn't start unless you pushed upward on the gear lever. This was not hard to do, with the ignition switch being left of the steering column.
He considered it an anti-theft feature.

- Eric

Northern Custom Cruiser

Hahaha my semi-working choke is my anti-theft feature.....

Thanks as always for all the help guys, im already a week deep into my next problem so im sure youll be hearing from me shortly (;