Neutral saftey switch woes

[flamesoldier]

I am trying to diagnose an otherwise healthy starting system with intermittent starting. I replaced the neutral safety switch because it was allowing me to crank starter in any gear. After replacing to a brand new switch it still allows me to crank in any gear. What could be going wrong here?

 

[Katfish]

NSS provides ground.
I would disconnect the wiring completely from the switch and see if the car starts. If so, the problem is upstream, something is grounded.

 

[flamesoldier]

NSS provides ground.
I would disconnect the wiring completely from the switch and see if the car starts. If so, the problem is upstream, something is grounded.

Ok sounds good

 

[MoparCarGuy]

This should help you find what is grounded and is allowing the starter relay to energize (See #5 below). Path is a supplied GND through the Neutral Safety Switch (NSS) when only in Park or Neutral. Pull the NSS connector off like Katfish suggested and try to start it. Problem is ground somewhere from #5 to the NSS or the NSS could be BAD causing this problem but won't happen with the wiring pulled at the NSS.
If it starts, try pulling the Starter Relay connector at #5. It should NOT start with that connector off.

 

[flamesoldier]

This should help you find what is grounded and is allowing the starter relay to energize (See #5 below). Path is a supplied GND through the Neutral Safety Switch (NSS) when only in Park or Neutral. Pull the NSS connector off like Katfish suggested and try to start it. Problem is ground somewhere from #5 to the NSS or the NSS could be BAD causing this problem but won't happen with the wiring pulled at the NSS.
If it starts, try pulling the Starter Relay connector at #5. It should NOT start with that connector off.

View attachment 124244 View attachment 124245

Pulled nss connector off car wont turn over so that is working

 

[MoparCarGuy]

So far you know the problem is at the NSS or the operation of the NSS by the internal shifter "comb".
It is far more common to have a "no start" condition than to have a "starts in any gear" condition.
It is unlikely that the internal comb is actuating the NSS and providing GND in all shifter positions so that seems to rule out "shifter adjustment".
Inspect that NSS connector end just to make sure the pin sockets look okay.

I suspect you have a new NSS that is BAD but some additional checks are needed to confirm. A multimeter is needed to test the center pin of the NSS to GND.
Your symptom is "starts in any gear", so that means that the center pin is grounded (zero ohms) in any gear. You can test your original NSS on the workbench with the meter as well. Measure center pin to the NSS body without pushing the plastic plunger and then test it while pushing the plastic plunger.
Pressed = GND <zero ohms & START enabled>
Not pressed = OPEN <no START>

You can also read this thread <LINK>about the NSS and the internal comb that presses the plunger in PARK/NEUTRAL to supply the GND needed to START.
***I am not suggesting you need to pull the transmission pan to see the comb mechanism. Just read through it so you know how it all works.***

Let us know what you find using a multimeter.

 

[flamesoldier]

So far you know the problem is at the NSS or the operation of the NSS by the internal shifter "comb".
It is far more common to have a "no start" condition than to have a "starts in any gear" condition.
It is unlikely that the internal comb is actuating the NSS and providing GND in all shifter positions so that seems to rule out "shifter adjustment".
Inspect that NSS connector end just to make sure the pin sockets look okay.

I suspect you have a new NSS that is BAD but some additional checks are needed to confirm. A multimeter is needed to test the center pin of the NSS to GND.
Your symptom is "starts in any gear", so that means that the center pin is grounded (zero ohms) in any gear. You can test your original NSS on the workbench with the meter as well. Measure center pin to the NSS body without pushing the plastic plunger and then test it while pushing the plastic plunger.
Pressed = GND <zero ohms & START enabled>
Not pressed = OPEN <no START>

You can also read this thread <LINK>about the NSS and the internal comb that presses the plunger in PARK/NEUTRAL to supply the GND needed to START.
***I am not suggesting you need to pull the transmission pan to see the comb mechanism. Just read through it so you know how it all works.***

Let us know what you find using a multimeter.

View attachment 124249View attachment 124251View attachment 124252

Ok that isnt why my car isnt getting spark though that a whole nother problem i thibk its my distributor i was rotating while starting and got some spark so thinking thats my spark problem

 

[flamesoldier]

****Update! I adjusted the magnetic pickup and cut the line from blue field tie in into msd power, msd said that is in accurate no field wire of any kind should be tied in with ign1 and ign2, they believe the field terminal tie in line was shorting out msd box to cause no fires

 

[MoparCarGuy]

You moved to a new issue with ignition. That is independent of a “starts in any gear” problem.

 

[rklein71]

My 74 Cuda starts with the NSS disconnected. Need to find out how the relay is grounded, ah someday.

 

[flamesoldier]

@MoparCarGuy i did all the testing today. Both nss had 1.8 and 2.2 in both neutral and park. All other gears didnt give multimeter value so i assume thats 0. So now i assume based on what your saying is my rooster comb must be worn out. Because both switches work. I read less than 10 ohms resistance for center pin is a good working nss, however you said it should be zero?

 

[MoparCarGuy]

So, to summarize what you just said earlier and what you just tested...
SYMPTOM: Your car turned over in any gear selector position. This indicated the starter relay was receiving a GND to the Starter Relay location #5 all of the time. The problem is a GND somewhere to the Starter Relay location #5 down to the NSS or internal to the transmission comb actuating the NSS.
TEST 1: You removed the NSS connector from the NSS and the car did not turn over. This indicated the GND was removed from the Starter Relay location #5.
TEST 2: You replaced the NSS with a new NSS and the problem remained. It turned over in any gear.
TEST 3: You removed the NSS connector and the car once again did not turn over. This made the NSS suspect again even though a new NSS was installed because you had a GND supplied to the Start Relay all of the time in any gear.

TEST 4: NSS Testing
You used your multimeter (set to resistance, ohms) and measured from the center-pin to a ground (body of NSS or the transmission case). You did this on the NSS in the installed position in the transmission.
The readings you got:
1.8Ω while in N - Neutral
2.2Ω while in P - Park
No reading in R - Reverse, D - Drive, 2 - 2nd, or 1 - 1st which I take you to mean OPEN (essentially infinite Ω) on the multimeter.

If that is correct, then your NSS tested good as it supplied a center-pin GND only when in Park or Neutral. It did not test that your backup lights work only in REVERSE.
The next step is to figure out why your car starts in any gear when the NSS connector is connected even though your NSS is not supplying that center-pin GND while in R, D, 2, or 1. That ground is coming from somewhere when the wiring is connected to the NSS.
The results you have found do not match up well with the original symptom.

Next test is to turn the key switch to the RUN position and check your backup lights in every gear position. The goal is to see if you only get the backup lights lit in REVERSE. We are making sure the NSS lights the backup lights using the 12V on one outer pin through the NSS to the other outer pin to light the backup lights. Essentially, the outer two NSS pins are connected but only in REVERSE. This check is just to see if the NSS does the backup lights function and is separate from the "starts in any gear" problem.

I cannot rule out an intermittent problem with the NSS since you have conflicting results, namely no start when NSS connector is disconnected AND an NSS that appears to be working correctly when resistance-tested. This is a real head-scratcher.

Anybody else have any ideas? Could his NSS wiring have an internal short that is intermittent and only shows up when he makes the NSS connector to NSS connection?

 

[flamesoldier]

So, to summarize what you just said earlier and what you just tested...
SYMPTOM: Your car turned over in any gear selector position. This indicated the starter relay was receiving a GND to the Starter Relay location #5 all of the time. The problem is a GND somewhere to the Starter Relay location #5 down to the NSS or internal to the transmission comb actuating the NSS.
TEST 1: You removed the NSS connector from the NSS and the car did not turn over. This indicated the GND was removed from the Starter Relay location #5.
TEST 2: You replaced the NSS with a new NSS and the problem remained. It turned over in any gear.
TEST 3: You removed the NSS connector and the car once again did not turn over. This made the NSS suspect again even though a new NSS was installed because you had a GND supplied to the Start Relay all of the time in any gear.

TEST 4: NSS Testing
You used your multimeter (set to resistance, ohms) and measured from the center-pin to a ground (body of NSS or the transmission case). You did this on the NSS in the installed position in the transmission.
The readings you got:
1.8Ω while in N - Neutral
2.2Ω while in P - Park
No reading in R - Reverse, D - Drive, 2 - 2nd, or 1 - 1st which I take you to mean OPEN (essentially infinite Ω) on the multimeter.

If that is correct, then your NSS tested good as it supplied a center-pin GND only when in Park or Neutral. It did not test that your backup lights work only in REVERSE.
The next step is to figure out why your car starts in any gear when the NSS connector is connected even though your NSS is not supplying that center-pin GND while in R, D, 2, or 1. That ground is coming from somewhere when the wiring is connected to the NSS.
The results you have found do not match up well with the original symptom.

Next test is to turn the key switch to the RUN position and check your backup lights in every gear position. The goal is to see if you only get the backup lights lit in REVERSE. We are making sure the NSS lights the backup lights using the 12V on one outer pin through the NSS to the other outer pin to light the backup lights. Essentially, the outer two NSS pins are connected but only in REVERSE. This check is just to see if the NSS does the backup lights function and is separate from the "starts in any gear" problem.

I cannot rule out an intermittent problem with the NSS since you have conflicting results, namely no start when NSS connector is disconnected AND an NSS that appears to be working correctly when resistance-tested. This is a real head-scratcher.

Anybody else have any ideas? Could his NSS wiring have an internal short that is intermittent and only shows up when he makes the NSS connector to NSS connection?

Yes that is all correct i did however fix the intermittent starting issue. The issue was the distributor pickup magnet needed adjustment. Now for the NSS problem i do not have reverse lights fuse is good and lightbulbs are good. I can still crank her up in every gear.

 

[flamesoldier]

So, to summarize what you just said earlier and what you just tested...
SYMPTOM: Your car turned over in any gear selector position. This indicated the starter relay was receiving a GND to the Starter Relay location #5 all of the time. The problem is a GND somewhere to the Starter Relay location #5 down to the NSS or internal to the transmission comb actuating the NSS.
TEST 1: You removed the NSS connector from the NSS and the car did not turn over. This indicated the GND was removed from the Starter Relay location #5.
TEST 2: You replaced the NSS with a new NSS and the problem remained. It turned over in any gear.
TEST 3: You removed the NSS connector and the car once again did not turn over. This made the NSS suspect again even though a new NSS was installed because you had a GND supplied to the Start Relay all of the time in any gear.

TEST 4: NSS Testing
You used your multimeter (set to resistance, ohms) and measured from the center-pin to a ground (body of NSS or the transmission case). You did this on the NSS in the installed position in the transmission.
The readings you got:
1.8Ω while in N - Neutral
2.2Ω while in P - Park
No reading in R - Reverse, D - Drive, 2 - 2nd, or 1 - 1st which I take you to mean OPEN (essentially infinite Ω) on the multimeter.

If that is correct, then your NSS tested good as it supplied a center-pin GND only when in Park or Neutral. It did not test that your backup lights work only in REVERSE.
The next step is to figure out why your car starts in any gear when the NSS connector is connected even though your NSS is not supplying that center-pin GND while in R, D, 2, or 1. That ground is coming from somewhere when the wiring is connected to the NSS.
The results you have found do not match up well with the original symptom.

Next test is to turn the key switch to the RUN position and check your backup lights in every gear position. The goal is to see if you only get the backup lights lit in REVERSE. We are making sure the NSS lights the backup lights using the 12V on one outer pin through the NSS to the other outer pin to light the backup lights. Essentially, the outer two NSS pins are connected but only in REVERSE. This check is just to see if the NSS does the backup lights function and is separate from the "starts in any gear" problem.

I cannot rule out an intermittent problem with the NSS since you have conflicting results, namely no start when NSS connector is disconnected AND an NSS that appears to be working correctly when resistance-tested. This is a real head-scratcher.

Anybody else have any ideas? Could his NSS wiring have an internal short that is intermittent and only shows up when he makes the NSS connector to NSS connection?

I was also thinking the plastic comb piece on the lever on inside of transmission is worn. There was little bright mini ball attached to something on the arm possibly a detent of a sort in the hole as best as i could see.

 

[MoparCarGuy]

You might try pulling the entire NSS wiring cable up into the engine compartment and inspect it for any damage that could cause an intermittent short.
It is a stretch but you could also ohm out the cable thoroughly just to make sure it is not your issue.

I do not suspect the transmission comb or plastic actuator piece for the NSS. That all seemed to be testing as working properly (GND only supplied in Park and Neutral).

 

[flamesoldier]

You might try pulling the entire NSS wiring cable up into the engine compartment and inspect it for any damage that could cause an intermittent short.
It is a stretch but you could also ohm out the cable thoroughly just to make sure it is not your issue.

I do not suspect the transmission comb or plastic actuator piece for the NSS. That all seemed to be testing as working properly (GND only supplied in Park and Neutral).

I did test the middle female port of plug remove from the switch. it had ohms resistance of 116.3 whatever that means

 

[flamesoldier]

You might try pulling the entire NSS wiring cable up into the engine compartment and inspect it for any damage that could cause an intermittent short.
It is a stretch but you could also ohm out the cable thoroughly just to make sure it is not your issue.

I do not suspect the transmission comb or plastic actuator piece for the NSS. That all seemed to be testing as working properly (GND only supplied in Park and Neutral).

Also with switch terminal removed and just the switch in the transmission, I didn’t have any resistance, just infinite ohms as you said in all other gears in theory, it’s not completing a circuit so the other ears shouldn’t start correct just the gears that have a resistance number like my park and neutral?

 

[Challenger RTA]

Wrong starter relay? I think in the late 60's it was changed.

 

[Challenger RTA]

Not a trans man. But if the detente ball is wore or spring is bad. It would not close the switch for the starter to run. If it stuck it would close the switch.

 

[flamesoldier]

Wrong starter relay? I think in the late 60's it was changed.

Just put a brand new proper starter relay and tests and runs well