My 78 280z  rock auto special is a boat anchor... only two prongs and it simply switches on high pressure and low pressure. It is not what Nissan made (sensor output and switch on low pressure)... beware... rock auto lies.

Edited July 25, 20186 yr by 240260280

9 hours ago, 240260280 said:

My 78 280z  rock auto special is a boat anchor... only two prongs and it simply switches on high pressure and low pressure. It is not what Nissan made (sensor output and switch on low pressure)... beware... rock auto lies.

I don't think the people at Rockauto were trying to misrepresent the part. They just follow the compatibility charts provided by their suppliers. 

I looked at the information provided on the SMP and Beck-Arnley parts listed on Rock Auto. They list a parts number cross-reference that has many part numbers that line up to Nissan part numbering. I tried looking up the part number on Carpartsmanual.com, but I couldn't find it easily. I then put in the Nissan style part numbers into CourtesyParts.com. Here are the results (all of the positive hits came up with an oil pressure sender):

25070-80W00	300ZX
25070-55S00	200SX
25070-55S60	200SX
25070-N7600	No results
25070-P7100	300ZX
25250-S6000	300ZX
25250-S6001	720
25070-P8000	300ZX
25070-P8100	300ZX
25070-P9700	300ZX
25250-N7600	300ZX
25240-89908	No results

 

So did Nissan use the same part with different numbers, or did Beck-Arnley and SMP take too many liberties in their cross-referencing? I went to the SMP catalog and searched for 1978 280Z parts. It lists a "Switch - Oil Pressure Gauge" with the same part number listed in the Rockauto catalog. For applications of this part, here is the compatibility list:

Nissan 200SX (83-80) 

Nissan 280Z (78)

Nissan 280ZX (83-79) 

Nissan 300ZX (84)

Nissan 620 (79) 

Nissan 720 (85-80)

Nissan 810 (81-78) 

Nissan Maxima (84-82)

Beck-Arnley has a similar applications list in its catalog.

Thanks Steve. I still need one. If anyone has a used 78 3 prong switch please pm me ?

So the two prongs on the 78 are supposed to be on-off, and variable resistance. You're saying the 78 style sensor you got from rockauto does not operate like that?

There's always the Fiero.  

16 hours ago, 240260280 said:

My 78 280z  rock auto special is a boat anchor... only two prongs and it simply switches on high pressure and low pressure. It is not what Nissan made (sensor output and switch on low pressure)... beware... rock auto lies.

Two prongs is correct.  One prong is the pressure sensor and the other is the switch.  Maybe you picked the wrong prong?  Bottom of the T is the switch.

Thanks guys!  I'll hook it up and see what happens.  The documentation accompanying said that it was just a switch that activated on very low oil pressure or very high oil pressure. No mention of pressure-to-resistance feature for driving the oil gauge.

Don't forget that the switch is normally closed.  It opens with oil pressure.  That's the flaw in it, if you unplug the oil pressure switch the fuel pump runs with the key On.

You'll need another relay to make it act as a safety switch.

That diagram hurts my head...

 

On 7/25/2018 at 7:10 PM, 240260280 said:

Thanks guys!  I'll hook it up and see what happens.  The documentation accompanying said that it was just a switch that activated on very low oil pressure or very high oil pressure. No mention of pressure-to-resistance feature for driving the oil gauge.

Which Z car are you wanting to install this oil pressure switch?  240?  Assuming the sender that you are buying does have a pressure>resistance sensor in it you will want to compare the resistance values to your original.  If it works great.  I'd like to know.  I did something similar  years ago.  It was a bit convoluted, I got a T and then used the original sender on one port and another sensor designed for idiot lights on the other port for my fuel pump control.  It worked fine however it did look like something you'd see in an oil field.  If you can get one sender that has all the function in it that's great.

Edited August 3, 20186 yr by hls3073z