• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

Neutral Safety Switch Polarity?

Moparfiend

FBBO Gold Member
FBBO Gold Member
Local time
9:20 AM
Joined
Oct 27, 2017
Messages
3,494
Reaction score
3,951
Location
HOT
I am assuming there is no polarity on the connection to the transmission on my 1970 Sat’s neutral safety switch/reverse light harness. Correct?

Looks like brown center is the neutral safety open in gear and short in park and neutral?

So the other two (blk and blk-t) must be power and reverse lights?

Thank you in advance for providing clarity.

IMG_7760.jpeg
 
Last edited:
So new cable and new switch no bueno. I did the test with the motor not running and had it in reverse with the lights on and ignition on.

I have power to the neutral switch as measured at the engine side bulkhead D. But no voltage at C ie switch output when the transmission is put in R.

I don’t know what “makes contact “ or how inside the transmission. I assume it’s like a mechanical slide? I also assume the engine doesn’t need to be running?

So in summary trans in R, ignition on/engine off, 12V @D no voltage @C. New harness and switch.
 
You have to make sure the NSS is matched with the rooster comb in the transmission also or it will not work properly. If it was rebuilt who knows what is in it. Also did you test the switch itself out of the transmission?
I went through this goat rope.
1760522908397.png
 
Last edited:
Is there continuity through the outer contacts of the installed switch in reverse? If not, pull the switch, depress the plunger, do you have continuity through the outer switch contacts? Ensure there is only one seal in place, have seen inadvertently doubled up seals interfere with the switch function.
 
You have to make sure the NSS is matched with the rooster comb in the transmission also or it will not work properly. If it was rebuilt who knows what is in it. Also did you test the switch itself out of the transmission?
I went through this goat rope.
View attachment 1932660
The trans is a 1970. In the picture above is the only 3 contact switch the one on the right 69-up?
 
Auto Transport Service
Back
Top