Neutral safety switch

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downsr

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I have a 3 prong neutral safety switch on a 727 trans.How can you bench test this with ohm meter.Does it matter which way the plug goes on.
 
2 outer pins make reverse lamp circuit, center pin supplies ground to energize starter relay. So connector really cant go wrong either way its put on.
 
So put it in reverse and measure outside pins to ground .Put in park or neutral measure center pin to ground
 
downsr said:
So put it in reverse and measure outside pins to ground .Put in park or neutral measure center pin to ground
Click to expand...

In park or neutral center pin is common to body of switch. In reverse the 2 outer pins are connected to each other.
 
^^^ Neither of the 2 outer pins goes to ground; when reverse is selected, the 2 outer pins connect to each other, not to ground.
 
I do not get continuity between the 2 outer pins.What actually makes the switch change state
 
There should be a little plunger on the inside of the switch. This is moved in and out with the gear selection cam (rooster comb) inside the trans. I can't recall for sure, but I think the plunger out will connect the 2 outer contacts, but just move the plunger in and out and you should get a connection one way or the other..... unless the switch is not good any more. Or unless it is in the car and actuator (rooster comb) is not the right one. Rear up here:
http://forums.hotrod.com/mopar-musc...-up-lights-on-in-reverse-and-drive-positions/
 
The 3 prong switch worked in the original 70 727 trans.I bought another 727 trans and had it rebuilt.It had a 2 prong.I put my 3 prong in it since the wiring in the car is for a 3 prong.Maybe
i need to change something in the trans that actuates the switch since it had a 2 prong and now has a 3
 
First pull the switch and test it; as I recall, it will make connection when out and not make connection if you push in the plastic plunger. If good, then read the article I linked....
 
I don't recall a 2 wire switch. Single wire was neutral safety where reverse lamp switch was shifter mounted inside the cabin. 3 wire is combination switch. Anyway... The part inside the trans that changed is commonly called "rooster comb".
 
I think I saw a thread on another site about this problem. Apparently there are two different switches, with one being longer than the other. The difference is the reach of the switch into the trans. Hope that helps.
 
The switch activates reverse when the plunger is extended all the way out , the comb has 2 high points on either side of a" ditch" , the high points are metal and activate the park and nuetral positions on the switch by pushing it in , the forward 123 are an intermediate arc on the comb neither all the way out or in, the "ditch " allows the plunger to extend all the way out activating the reverse lights. You didn't say why you were testing it , if you aren't getting reverse lights try adding a couple of fibre washers to space the switch out a little enabling the plunger to extend further , this is how we fixed mine , if the nuetral safety function isn't working then remove the switch and test it as they mentioned above . My parts guy can only get 1 size of switch from Standard and this seems to be the solution to the reverse light problem many are experiencing , I'm thinking the switch they are selling is a little long and probably common to some other product line that they manufacture for .
 
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