Oil Pressure Gage and Sending Unit Revisited
@RedFish I have a fair number of photos of the gages when they were out last year. If you recall at that time I tested them mounted on the board with a power to the IVR from the car battery and resistors. Would there be any clues from last year work?
@Dana67Dart I think the easier check of the wiring may be to swap the temperature and oil pressure sender hookups. Yes?
Bet it is possible. There seems to be a few different ways pressure senders have been made. Really can't be sure what the Echlin design has inside. Some are pretty complex and if damaged inside it wouldn't take much to find a parallel path. I *thnk* the path would be more likely to show up at 14 Volts than whatever reference the ohm meter is using - probably a 1.5 volt AA battery.
FWIW one sold by BRE is stamped Pat 4079351
That's a 1978 patent that if I understand it correctly allows the manufacturer to use adjust the final build for the application. patent US4079351A - Pressure responsive sender - Google Patents
An much older design was patented in 1958 by King Seely. That one is mentioned in the unit section of 1970 Chilton's, but doesn't mention which car companies used it when. A bit less complicated.
US2846549A - Pressure indicating device - Google Patents
Chrysler's 1960s sender might have been yet another variation.
edit. FWIW. Scott Smith Harms post some photos of original on a '70 in this thread
Anyone have a picture of a correct 340 oil pressure sender?
@RedFish I have a fair number of photos of the gages when they were out last year. If you recall at that time I tested them mounted on the board with a power to the IVR from the car battery and resistors. Would there be any clues from last year work?
@Dana67Dart I think the easier check of the wiring may be to swap the temperature and oil pressure sender hookups. Yes?
Bet it is possible. There seems to be a few different ways pressure senders have been made. Really can't be sure what the Echlin design has inside. Some are pretty complex and if damaged inside it wouldn't take much to find a parallel path. I *thnk* the path would be more likely to show up at 14 Volts than whatever reference the ohm meter is using - probably a 1.5 volt AA battery.
FWIW one sold by BRE is stamped Pat 4079351
That's a 1978 patent that if I understand it correctly allows the manufacturer to use adjust the final build for the application. patent US4079351A - Pressure responsive sender - Google Patents
An much older design was patented in 1958 by King Seely. That one is mentioned in the unit section of 1970 Chilton's, but doesn't mention which car companies used it when. A bit less complicated.
US2846549A - Pressure indicating device - Google Patents
Chrysler's 1960s sender might have been yet another variation.
edit. FWIW. Scott Smith Harms post some photos of original on a '70 in this thread
Anyone have a picture of a correct 340 oil pressure sender?