Need info on oil pressure switch, Z53 gauges?

[RamAirZ]

Hey guys, I just picked up a 1985 Suburban 1/2 ton 2wd for a family/fun rig to play with. The dash cluster includes the big speedo and fuel gauge, as well as a voltmeter, water temp, oil pressure and clock. I can't find an RPO code list anywhere on the truck, but it has different seats (front's are blue buckets with blue console, rear is black), it has a different rear tailgate on it (replaced at some point??? has rear defogger so assume it's a later model), and some other slight modifications so not sure if this gauge setup is the original but I think it is. The Oil pressure gauge doesn't work, it's pegged all the way past 60 all the time. I have a 2 terminal oil pressure switch, and most of the switches I see at the parts stores for a truck with a pressure gauge it shows only 1 terminal, and the 2 terminal ones being for trucks with a light instead. Now I did find one through O'Reilly's that says 2 terminal, 1/4-18 thread, rally gauge Z53.

http://www.oreillyauto.com/site/c/de...3438&ppt=C0039

Do you think this is the one I need? I find it odd that this is the only one that has 2 terminals and for use with gauges but hard to find. Is this a rare thing on this truck or something? First truck (shoot, vehicle) I've owned where the oil pressure sensor has had so many options lol. All the other gauges in the dash work perfectly including the clock. Any info would be greatly appreciated

[Jonboy]

85 should have the 1 terminal, bell style sender. They didn't start using the 3 pin switch until sometime in 87.

[RamAirZ]

It's not a 3 terminal, it's a 2 blade. It had a connector on it that had a plastic snap that closed around it after it was plugged in. I also found a connector hanging in that same area that has the 1 blade. Maybe I should get a 1 and a 2 with a splitter and hook them both up lol. If I unplug the 2 blade connector from the switch the choke light stays on constantly. It's my understanding that they tied the choke circuit into the oil pressure switch in these years for some reason.

[impalamark]

hope this helps my truck has a oil pressure sender for the gauge in the dash nest to the dist.one wire AND an oil pressure switch down by the oil filter for the choke circuit
it is a two wire I think (haven't yanked it yet to be sure but two at least )
so your set up may have two also if you are fixing the dassh guage the sender for it is the one wire by the distributor . I'm told sometimes these ate on a "t" fitting in the same location
MArk

[RamAirZ]

Thanks for the info Mark! I'll have to check it out