Can you bench test this Neutral Safety Switch to see if it works?

[WH23G3G]

I'm still struggling to find out why my 65 Valiant won't start with the ignition key. All the wires that supply power to the relay and from the ignition switch through the firewall show power when the key is turned to on. The small gauge wire from the starter to the SOL is the only wire that doesn't show power when the key is turned. I was told the NSS might be bad or I figured since I rebuilt the steering column and had to reinstall the shifter cables it might be out of adjustment. Yesterday I perfectly adjusted the shift cable again according to the 65 Plymouth service manual but nothing changed. I did a test with a test light running from the positive cable to the NSS. I hooked up the test light to the positive battery and probed the threaded terminal end of the switch and the test light did not light up. However, of course if you probed the metal body of the switch it would light up. I never messed with NSS when I first got the car years ago so I don't know why it would have gone out all of a sudden but it's been sitting for a couple years outside. The switch itself cleaned up good. I was wondering is there an actual way to bench test this switch to see if it works. I know it acts as the ground because it's just one terminal. I had a mechanic test the switch today and he said it doesn't work but he's not familiar with this old of a vehicle.

[A383Wing]

use OHM meter...put switch in a vise, put one lead of meter on single terminal of switch, put other meter lead on threaded body of switch, you should have no continuity,

With leads still connected, have someone push in the round thingy on opposite end of switch, if you have continuity, switch is good

Bryan

[WH23G3G]

Ok I don't have a vise here at the house. But I was able to hook up an ohm meter the the threaded terminal and touch the other lead to the threaded part that goes into the transmission. Then I pushed in the plunger and didn't hear a tone. So it's good right?

[A383Wing]

nope...you should hear a tone when switch makes contact connection inside...that's what turns on the ground for starter relay

Bryan

[WH23G3G]

I havent tested for continuity much before so I followed the instructions in the OHM meter book that came with it. It seems pretty simple. It says if you hear a tone it means circuit is closed or shorted, and if you hear no tone then the circuit is open. So if I don't hear a tone testing this switch that's bad? It does beep if I have the threaded terminal probed and then probe the plunger nail in the center of the plunger.

[A383Wing]

Meter should beep when you touch both leads together

meter should not beep when you touch threaded terminal & threaded section on switch with meter leads without pushing in plunger

meter should beep when you touch threaded terminal & threaded section on switch while pushing in plunger on switch

sounds like yer switch is bad

Bryan

[WH23G3G]

Ok now I'm wondering if anyone knows where to get this switch new? I only see it on EBAY NOS for a lot of money. Is there anywhere that would still have an aftermarket unit? I'd hate to pay $90 for an NOS one and have it not fix the problem.

[WH23G3G]

Ok I had several different mechanic shops bench test this NSS that I have off my 65 Valiant Slant Six automatic. Everyone said the switch tested bad. So I was told if I want to find out for sure and to see if the car will start with the ignition key to disconnect the terminal on the NSS and ground it out to the body. Well I did that and I even tried several different spots just in case it wasn't a good ground. Nothing changed at all. One mechanic told me the ammeter gauge is the whole problem but I'm not convinced since I tried two different ones. I did probe the studs on the back of the ammeter and one side reads over 12 volts and the other side read 10. something. I don't remember which side. What does that tell you? The starter relay has been replaced now 5 times, I tried to ground it out with a ground strap and nothing changed. Still the only way to start it is by touching the BATT and SOL terminal together with a screwdriver. The heater motor works, the wiper motor barely works, the headlights work, the washer system works, the dome light works. I was tempted to buy a brand new dash harness from Year One, but even discounted it was $475. I do have a new correct engine/forward light harness hooked up so hopefully the terminal conditions are ruled out there. The battery cables are all clean and newly made.

[A383Wing]

bad ignition switch or bad connection at connector to ignition switch?

Bryan

[WH23G3G]

When I replaced the ignition switch I also replaced the ignition lock cylinder. I didn't think there was but one way to install the new lock cylinder into the ignition switch. Is that true? I know I have two original ignition switches but they didn't work either. I show power at every wire on the back of the ignition switch.

[A383Wing]

there should be a wire that only gets power when you turn to "start"....I ferget which color.....brown comes to mind..but don't quote me

Bryan

[WH23G3G]

I think it's the yellow. It has power at the switch when I turn the key. It has power inside at the back of the bulkhead connector when I turn the key. It changes from a yellow wire to yellow w/black tracer in the engine compartment and goes to the IGN spot on the firewall relay and it does show power too when the key is turned. I'm almost going to give up and buy the new harness. I know it can't be a defective part. Of all the parts I've put on every car I've had I've actually never had one defective right away eventhough it appears a lot of people do. I don't know what other diagnosis to try. Some trying to get some more ideas. I go there where the car is located on my day off do whatever test I've figured out to try and if it doesn't work I leave. Because I don't know what else to try. I dont think it matters because it doesn't on my Charger but at the starter. Originally the two wires going to the starter were soldered and wrapped in a rubber lug together so you could kinda bolt it right on to the starter. My cables had to be custom made. So I have a straight red positive cable going to the big starter lug, and then a whole separate correct gauge wire going from the small stud on the starter to the relay. Does that matter? That is the wire that never lights up when you probe it unless you jump the relay with a screwdriver.

[John_Kunkel]

Testing the NSS for continuity on the bench won't prove that it's supplying a good ground when installed in the transmission. Install the switch and test for continuity to ground with the shifter in the P and N positions.

If the shift cable is slightly out of adjustment the switch won't supply a ground even if it's good.

[WH23G3G]

So again I probe the terminal and the hex head of the NSS with the transmission in park? Do I leave the terminal connected to the NSS? I thought the cable might be out of adjustment. So I followed the factory adjustment procedure and did it exact. How do you tell if the cable is out of adjustment? Everything shifts crisp on the shift indicator. I know its got to be something simple keeping this thing from starting since everything else on the car works.

[John_Kunkel]

With the wire disconnected, check for continuity between the threaded stud on the NSS and the transmission case with the shifter in P and N.

If you're in doubt about the cable adjustment, remove the NSS and see if the metal contact in the transmission is dead center in the hole in P and R. In many cases you'll need a mirror to see directly into the hole.

[WH23G3G]

So I probe the threaded terminal and somewhere on the transmission case? What should the ohm meter do? Beep? I took out the switch and looked for the fingers but I didn't know what they meant by centered, I mean they look like they're in the center of the hole when I look through. I don't know how you determine if they're centered enough to be properly adjusted. 

[pistolgrip]

not sure about your year, but my 74 has a ballast resister on the fire wall, it is made of a glass like material, mine has 4 prongs on it. Two are for starting and two are for run. I keep  a new one in my glove box, just in case. Have been left stranded because car would not start ( turn over ). Hope this helps

pistolgrip

[WH23G3G]

Thanks all. It definitely was the NSS. I put a new one in and it starts by the key just the way it should. Well it doesn't start but I think it just might be out of gas. I'm not sure though because the gas gauge doesn't work very good. I didn't know this year is supposse to have a separate voltage regulator on the dash for the gas gauge. So since I didn't see it listed in the parts catalog or the repair manual I removed it. Now I think that's why the gauge doesn't work. So I'll add some more gas and put the regulator back in. I should be able to get it started now.