Oil pressure sender (1 Viewer)

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So after some continuity checks, and besides the obvious failure between filter and center terminal connector (white wire), I found there was no continuity between the metal center terminal and the wire that was connected to it. The conductor had corroded in the terminal swage. I managed to pull the plastic fittings off the terminals and rebuilt the entire cable harness back to what was there originally since the sensor and dash gauge used to work. Pictures below show failed conductor location and hints on terminal removal from the cable fittings. I used the original terminals and soldered the new cable splices to them. Gauge is reading pressure again. So glad I did not have to pull the instrument panel out.

CABLE TERMINAL FITTING REMOVAL.jpg


CENTER POST TERMINAL WIRE FAILURES.jpg
 
Thank you for the pictures of the connector insides!

For getting the oil pressure sender connector out, this piece flips up. It took me like an hour to figure that one out, I wish I cleaned it up better from the start so I could see the seams better. And that was after spending an hour in the 1997 connector manual where I couldn't find it either.
IMG_8196.jpg

Also an FYI, the 2 pin filter is just a Panasonic ECQE series polyester film capacitor, this one being rated at 250V, 0.47 uF. It has the Panasonic part number ( ECQ-E2474E07) on the end of it.
They are AC tolerant so polarity doesn't matter if you needed to just grab one off mouser for 60 cents and solder it in.

I suspect it was done for noise emission reasons, you can use the capacitor to induce a voltage opposite of the pulsed signal from the oil pressure sensor, and then putting them together as a twisted pair means that as long as they have equal impedances at the other termination (and therefore equal and opposite currents), the EMF emissions will have destructive interference and reduce noise that could be picked up by the radio to pretty much zero. There's more to getting the currents to match when using a cap to generate the opposite signal, but when done correctly that's the end result.

Or maybe they just used it as a storage bank to average out the pulses, but IME .47uF is way too small to have ay effect on that for a load of this size. (the lightbulb test of the gauge draws over 250 mA)
 
Thank you for the pictures of the connector insides!

For getting the oil pressure sender connector out, this piece flips up. It took me like an hour to figure that one out, I wish I cleaned it up better from the start so I could see the seams better. And that was after spending an hour in the 1997 connector manual where I couldn't find it either.
View attachment 2723302
Also an FYI, the 2 pin filter is just a Panasonic ECQE series polyester film capacitor, this one being rated at 250V, 0.47 uF. It has the Panasonic part number ( ECQ-E2474E07) on the end of it.
They are AC tolerant so polarity doesn't matter if you needed to just grab one off mouser for 60 cents and solder it in.

I suspect it was done for noise emission reasons, you can use the capacitor to induce a voltage opposite of the pulsed signal from the oil pressure sensor, and then putting them together as a twisted pair means that as long as they have equal impedances at the other termination (and therefore equal and opposite currents), the EMF emissions will have destructive interference and reduce noise that could be picked up by the radio to pretty much zero. There's more to getting the currents to match when using a cap to generate the opposite signal, but when done correctly that's the end result.

Or maybe they just used it as a storage bank to average out the pulses, but IME .47uF is way too small to have ay effect on that for a load of this size. (the lightbulb test of the gauge draws over 250 mA)


i offer Both the Early and Later OIL sender SUB harneses .........











the early one is toyota disc. NLA , I hand make reproduction ones ussing 100% TOYOTA genuine electrical parts


the later one is a JAPAN spec. sourced part ....


hope i can help you

thanks matt


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