I installed a new oil pressure sending unit on a 56 Merc. with a 292 cu. in. ( not a 312). I can't get it to read the oil pressure in the engine. I connected a mechanical gage and it records good pressure (65 to 70psi) The sending unit I used has a dual post on top of it and I only have one wire running from my gage. When I ground the wire with the key on the gage goes all the way to max. So its getting voltage. I don't know why they put a dual post on top of the sending unit or why my gage wouldn't register any pressure. Does anybody know what I could check out?

thanks, Tom

roviwancanobe

Tom, your two post sender may be one terminal for ground and the other for the sender (sometime used to eliminate grounding problems through the threads due to sealer). Try grounding the other terminal on the sender and see if that helps. If not try touching a grounding wire to the body of the sender as a test for no ground through the threads. Mike

1956 Fairlane Victoria (ORREO)

 

Overlooking Beautiful Rimrock AZ

Did your old sending unit have two posts? One thing to be carefull of is using teflon tape on the threads. It might keep the sending unit from grounding so use regular pipe sealant.

Ol'ford nutCentral Iowa

56 Vic w/292 & 4 spd.

56 mercs had a condenser strapped on the sending unit which if not there your unit will not work.

-Gary Burnette-

A ford unit is different from the merc, so make sure it's for a merc.

-Gary Burnette-

The sender I have must be a Ford. It doesn't have a condenser on it. I bought it at Classic Mercury in Ca. and he said it was for a 56 Merc. but I have a 56 Ford and it looks just like it. Its not a grounding problem. Does anybody know where I can get the right sender for my Merc?     please help!!

thanks, Tom

roviwancanobe

Now I'm confused.  The '56 Ford had an idiot light, not a gauge.  Does the Merc have a gauge like I think it does?  The two types of senders are not interchangeable.  I think the condenser Gary referred to was actually a radio noise suppressor.  The gauge won't care if it's on there or not.

John - "The Hoosier Hurricane"

John, The 56 mercury had a sending unit very similer to the pickup truck, a fairly good sized unit with a small condenser strapped to it similer to the one used with the gas tank. The 56 mercury unit has two ends coming off it, one for the condenser and one for the ign. wire. The 56 ford is totally different and will not work as it works the idiot light and the mercury works a needle like on a 57 ford.

-Gary Burnette-

I also ment to ad that the mercury does have a gauge.

-Gary Burnette-

Sorry Guys, I didn't know a 56 Ford had a light. The oil pressure sending unit is for a gage. I bought it on line its a Motorcraft part no. B6A-9278-A tested it with con'ty meter worked ok put it in the car and just moved the gage about 1/8". Then I called Classic Mercury they said they have one for a 56 Merc. bought it , tested with con'ty meter, put it in the car and it does the identical thing and it looks the same. I took the wire coming from the gage and grounded to frame and it moved to max. Like I said earlier the engine does have good pressure. Don't know where to go from here! Maybe I still don't have the right sending unit if a Ford is different. Does anybody know where I could find a sending unit that I know is the right one for a 56 Merc.

please still need HELP

Tom

roviwancanobe