NB oil pressure gauge runs backward
 

I did this mod untitled to the gauge itself and installed the earlier NA sender unit that reads various ohms. With ign on, but not running, the gauge "primes" to 0psi ish in the cluster. I did adjust the gauge needle to read there at key on. However, when the enging is running the needle swings left and buries itself into the plastic on the LEFT. Digging around various threads it seems I may have a bad sender. If I recall correctly the sender reads 180ohm without any pressure to it. Shouldn't it read 0ohm ish?

Ideas? Not opposed to getting another sender unit. I've pulled the cluster apart and double and triple checked mine vs the images and instructions. Ok at ign on and backward at running seems like it'll be the sender unit.

The NA sender works in the opposite of most. The VDO sender that the linked mod relies on uses a 10-180 ohm signal from 0-80 PSI. The NA oil pressure gauge is the opposite - lower pressures map to higher resistances. The behavior you are seeing is as expected; the sender is working correctly.
You need to either replace the sender with a unit like the VDO unit, or get an NA oil pressure gauge in your cluster.

Ah, that is what I was thinking. Thanks.

These guys figured it out: TDR Oil Pressure Kit 95-05
And this guy: Longacre Oil Pressure Gauge Bundle - $198.95 : Advanced Autosports, Miata Race Parts, Spec Miata and TRANS AM Race Car Sales, Service, Build & Rentals Support in Midwest

I was just getting ready to order this. Cheaper than the kits and I think serves my purpose .


Part number sourced from earlier links.

An NA oil pressure gage won't fit in a NB cluster... I tried to install a NA "real pressure gage" in my NB ( with the coresponding sender ) but to my disappointment, the gage wouldn't fit ( not teh same fixing pattern, not the same size, nor deapth... even if the visible area looks pretty much the same!

It will fit with modification. Read the thread.

Well sorry... i missed that:bowdown:

too bad i didn't find the thread earlier, that would have prevent from selling back the earier gage and sender i ordered ....