Oil pressure switch or sending unit?
rumblephish
Jeeper
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- Location
- Central California
- Vehicle(s)
- 1978 Jeep CJ-5 "Levi's" edition, original AMC 304 V8, T-150 transmission, Dana 20 transfer case, AMC 20 rear end. All stock except for a hotter ignition.
I'm confused and I need some help!! 
What's the difference in the oil pressure SWITCH and the oil pressure SENDING UNIT?
I replaced my oil pressure gauge with a new AutoMeter gauge and replaced the original oil pressure SENDING unit with the one that came with the gauge (similar to the OE unit). This is the large bell shaped unit where the sending wire snaps onto a post/nipple on the end of the unit.
Just before the sending unit there is a switch with a 3 prong plug attached to it. There are two wires coming off of it, one red and one green. The red goes up and plugs in the choke solonoid on the passenger side of the carb. The green wire loops back and plugs into itself.
What is this switch for and why does it plug into the carb? From what I can gather online it is an oil pressure switch for an idiot light on the dash (newer CJ's). My CJ is a 78 and did not have an oil light on the dash. Just an oil pressure gauge.
If this is correct do I even need to have this switch plugged in? And why does it go to the carb?
HELP!!!

What's the difference in the oil pressure SWITCH and the oil pressure SENDING UNIT?
I replaced my oil pressure gauge with a new AutoMeter gauge and replaced the original oil pressure SENDING unit with the one that came with the gauge (similar to the OE unit). This is the large bell shaped unit where the sending wire snaps onto a post/nipple on the end of the unit.
Just before the sending unit there is a switch with a 3 prong plug attached to it. There are two wires coming off of it, one red and one green. The red goes up and plugs in the choke solonoid on the passenger side of the carb. The green wire loops back and plugs into itself.
What is this switch for and why does it plug into the carb? From what I can gather online it is an oil pressure switch for an idiot light on the dash (newer CJ's). My CJ is a 78 and did not have an oil light on the dash. Just an oil pressure gauge.
If this is correct do I even need to have this switch plugged in? And why does it go to the carb?
HELP!!!