Need Help with oil pressure safety switch

[mopar_ja]

I have a 3 prong safety switch with markings that are P, S, I. I know they mean Pump, Starter and Ignition, what I dont know is what they are equal to C, NO, NC. This is what I put together from different articles, someone please tell if this right or if I F'd it up.

Pump= Common
Ignition= Normal Open
Starter= Normal Closed

[mopar_ja]

One more question since the bottom the relay box is exposed where all the leads come out what would be a good potting compound to seal it off from the elements; silcone, rtv, expoy, home made rubber boot. something that can be easily be removed and replaced if i need to repair a connection.

[camoit]

What does the switch show you when you use an home meter on it?

[mopar_ja]

don't have clue, did not even attempt to put on meter and wouldn't know what to look for if i did, i know i would see numbers but that is all they would be to me.

[camoit]

OK do this then. Get a test light and a battery. hook one post of the battery to any connector of the switch. (I would guess that there is only 3 connectors on it.) On the other battery post hook up your test light wire. Check each post and see witch one lights up the light. That is Normally closed WITH OUT PRESSURE. That only leaves the Normally open and the common to figure out. 20 PSI of air pressure run through a regulator will kick the switch into the other state. Are the 3 prongs all lined up in a row or is there 1 that is off?

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Normally there is one that is out of position like on a relay that will be the com.

[pennyman1]

Your chart is right in your first post - although the common goes to the relay instead of the pump if you are using one. I ran mine for years without one until I realized how much of a voltage drop there was without the relay. Unless you live in the salt belt and are driving in the winter, it will take years before the terminals corrode on the relay or pressure switch contacts. You could use silicone dielectric grease in the plug and on the terminals if you wish.

[mopar_ja]

Want to say thanks for everyones help and input in this, i got the truck running adjusted valves and the miss went away and now adjusting carb thinking the 60 primary jet might be a little much for this elavation so going to swap it for what exactly not sure thinking might try a 50.

[camoit]

Glad the engine runs for you. At lease it was nothing major to fix the miss. I just was not willing to invest more into the stock engine. I figured it was something like a valve adjust. But I think my replacement truck will have the return on investment I'm looking for. It was nice to meet you and your brother. Glad everything is working out for you so far. Now how about that trailer and 5th wheel. $1500 or BO. I know a D50 can pull it with 10,000 LBS on the trailer. It pulls nice and straight. Just never ever pull a trailer in 5th gear on these trucks. The trany pocket bearing will take a crap. Trust me on this. I found out the hard way. I can set you up with the wiring, plug, 5th wheel, pretty much a turn key deal. Should not take but a morning to mount it into the bed for the run back home, unless you want to trailer it up there. That might be the best thing because the tires are looking a little old and weathered.