Troubleshooting nuetral safety switch

[jborg]

Can anyone explain how to t-shoot a nuetral safety/reverse light switch?
Also a starter relay. I remember with fords you can start a car with a screw driver across the terminals of a starter solonoid.
Can this be done with Mopars?
Thanks!

 

[mrsnicks]

Take the connector off the starter relay that goes to the NSS. Get an alligator clip jumper wire and ground the NSS stud on the starter relay to the negative side of the battery. Removes the NSS from the equation.

Yes, you can use a screwdriver to start the car from under the hood. Or get a remote start switch. I think the ignition switch has to be in the run position if you want the engine to run. If you want to just bump the engine over a little bit leave the ignition key out.. .. but it's been a while since I've done it.

 

[jborg]

So which 2 wires do I short out?
Thanks for your help!

 

[747mopar]

The 2 outer most pins are the reverse light, when in reverse you should have continuity between them (a connection). The middle pin simply grounds to the tranny when in neutral providing the needed ground to the neutral safety relay.

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This pic of a neutral safety relay should help. If your wanting to test to see if the neutral safety switch is the cause of the car not turning over simply provide a temporary ground to the ground terminal. If you want to test to see if the neutral safety switch is the reason for reverse lights not working just unplug the harness from the switch and jump the outer 2 terminals (can't remember if the ignition switch needs to be on) but jumping them should light them up.
View attachment 248613

 

[jborg]

OK so if I ground out the G terminal and short out I to S the engine should crank. This would take the sfety switch and relay out of the picture, correct?

 

[mopar 3 B]

OK so if I ground out the G terminal and short out I to S the engine should crank. This would take the sfety switch and relay out of the picture, correct?

just a ground wire to G will be all that is needed to bypass the safety switch. Jump the B & S to spin the starter. if you want it to start turn the ignition switch to run.

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if this thing has a manual trans make sure it is in neutral before turning the starter over from outside the car.

 

[747mopar]

OK so if I ground out the G terminal and short out I to S the engine should crank. This would take the sfety switch and relay out of the picture, correct?

Ground the G terminal but short S to B (starter, battery). The I terminal is the ignition switch meaning you would need to apply 12 volts to it.

 

[jborg]

OK, Im back at troubleshooting my "no crank" issue tonight. Thanks for all your help!
Here are my assumptions: (please correct me if I am wrong)

1- the I terminal should have 12 volts with the ignition in the start position.
2- if I remove the G wire and connect an ohm meter between it and the negative battery terminal it should read close to 0 ohms with the shifter in the park and neutral positions. If it doesnt the nuetral safety safety switch is bad.
3- the light are all working so my fusible link is good? In other words if the link is bad no lights would work?
4- My fuse block is not mounted. Would this be a problem? Could missing fuses cause a no crank issue?

Thanks again for all the help!

 

[nm9stheham]

1- the I terminal should have 12 volts with the ignition in the start position. YES
2- if I remove the G wire and connect an ohm meter between it and the negative battery terminal it should read close to 0 ohms with the shifter in the park and neutral positions. If it doesnt the nuetral safety safety switch is bad. YES
3- the light are all working so my fusible link is good? In other words if the link is bad no lights would work? YES
4- My fuse block is not mounted. Would this be a problem? Could missing fuses cause a no crank issue?


Thanks again for all the help!

1. YES
2. YES
3. YES
4. NO The ignition switch is fed through the fusible link and the ammeter.

The ammeter has not been mentioned and it has to be connected and good to crank.

 

[jborg]

1. YES
2. YES
3. YES
4. NO The ignition switch is fed through the fusible link and the ammeter.

The ammeter has not been mentioned and it has to be connected and good to crank.

I can short out the ameter to test that correct?

 

[747mopar]

Correct, all of the juice has to go threw the ammeter for it to work properly but it can be bypassed.

 

[jborg]

Testing Results

Here are the results of my testing last night:
On the starter relay:

small brown wire: grounded in nuetral, un grounded in park >>>bad nuetral safety switch??? (backup lights work)

yellow "I" wire: no 12 volts in run OR start (I measured between the wire and neg battery cable)>>>bad ignition switch or ameter. If the ameter were bad or disconnected wouldnt EVERYTHING be dead???

I ran a jumper between the + battery terminal and "I" terminal. Got a tiny spark. Shouldnt this have activated the relay???>>>bad relay???

The ameter didnt seem to move when operating the turn signals???

turn signals, horn, backup lights, interior lights all work. This means my fusible link is ok, right?

On a 69 this problem wouldnt have anything to do with the brakes, would it?

Thanks for all of your help with this!

 

[747mopar]

Here are the results of my testing last night:
On the starter relay:

small brown wire: grounded in nuetral, un grounded in park >>>bad nuetral safety switch??? (backup lights work)

yellow "I" wire: no 12 volts in run OR start (I measured between the wire and neg battery cable)>>>bad ignition switch or ameter. If the ameter were bad or disconnected wouldnt EVERYTHING be dead???

I ran a jumper between the + battery terminal and "I" terminal. Got a tiny spark. Shouldnt this have activated the relay???>>>bad relay???

The ameter didnt seem to move when operating the turn signals???

turn signals, horn, backup lights, interior lights all work. This means my fusible link is ok, right?

On a 69 this problem wouldnt have anything to do with the brakes, would it?

Thanks for all of your help with this!

The ground in neutral but not park makes me think you should check your linkage adjustment (might be off a fuzz).

When you put battery voltage to the "I" terminal did you make sure you had ground at the moment? Try grounding the ground terminal while putting battery voltage to the "I" terminal. If your car is wired correctly the ammeter being unhooked should mean everything will be dead. Also the "I" terminal will only get voltage while the key is held in the start position (as if you were cranking the motor over) and should have nothing in run.

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I would test the ignition switch as well, I don't have my manual in front of me but you should have a "B" terminal that supplies the 12V. Make sure it's getting 12V and if so make sure the "I" terminal is getting 12V while holding the key in start.

 

[nm9stheham]

If you have had a transmission rebuild or modification, there is a part in the trannie that activates the NSS, called the 'cockscomb'; there are 3 different types and you have to have the right one for your particular trannie.

Also, there are 2 different NSS's and one is longer than the other. If the shorter one gets put in by mistake, then you're gonna have NSS issues. So, you need to check out the parts in the trannie: the NSS and the 'cockscomb' that activates it.

 

[jborg]

Can you get the cockscomb out without completely disassembling the trans?