Neutral safety switch

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63SplitWindow

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I just changed out the neutral safety switch on my 73 due to a fluid leak that appeared to be coming thru the switch. Now the engine cranks but I lost spark. If the new switch is bad, it will stop the motor from cranking, correct? Not kill spark....at least that is how I remember these thing working.
Thoughts?
 
I would install your old neutral safety switch to see if it starts. If it does, the new switch is your problem. If not, you will have to do some more investigation to see what your problem is.
 
I just did a bunch of research into these switches. My understanding is the switch completes needed ground to starter when you’re in park or neutral. So dead key and no click and no crank if you’re in gear. Not a crank and no spark situation.
 
I just did a bunch of research into these switches. My understanding is the switch completes needed ground to starter when you’re in park or neutral. So dead key and no click and no crank if you’re in gear. Not a crank and no spark situation.
He said, Now the engine cranks, but I lost spark. So it must be grounded, if he is able to crank it over.
 
The NSS has nothing to do with ignition.....only starter crank/no crank. It just interrupts/connects the ground wire circuit to the starter relay allowing/not allowing the starter relay to engage and connect contacts to supply juice to the starter solenoid wire. It also is the backup light switch. (outer pins)
 
Chances are you bumped something up by the distributor/firewall during your repair. Check all those connections and run some tests for electricity to those components.
 

Nothing to do with spark.

Clip a meter to coil + and ground, turn key to run. You should NOT have full battery V but rather some lower, maybe 6-10v. Now twist key to "start" and read meter while cranking. Coil should be at least 10.5 and ideally should be 'same as battery" while cranking

Clip meter to coil NEG and ground. Key in run, you should have low voltage, perhaps 1-2V This shows the coil is getting "run" power and that the box and coil are drawing current.

Separate distributor pickup connector. With key in run, and a test spark gap rigged to coil tower, tap the bare terminal of the distributor pickup connector on the engine bay side to ground, not the distributor side. Each time you tap to ground, you should get one single nice hot "snap" spark.

"Work" the dist. connector in/ out several times to scrub terminals clean and to feel for tightness. Inspect inside cap, for rust and debri and strike damage to pickup and reluctor. wiggle shaft to check for shaft/ bushing wear.
 
If you want to eliminate the NSS from the system to rule it out, just unplug the wire from the starter relay and ground the terminal. The arrow shows the location the NSS wire should be hooked to on the starter relay, so, just unplug that wire and ground the terminal. That eliminates the NSS.
IMG_9651.jpg


That being said, if the car cranks but has no spark that's not the NSS. It should stop the starter from cranking. But, one less variable isn't a bad thing.
 
Just be careful doing that, as now the car will start in any gear.

I mean, sure, but why wouldn't you always check to see if the car was in gear before you started it? You have to check anyway, even with the NSS if you skip checking to see if it's in gear you're gonna have issues if you just let the clutch back out.
 
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