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View Full Version : Throttle Potentiometer check: which one??



tz779
10-28-2007, 02:33 PM
LRC people:
i have a LRC manual (Rev Sept 88), and it says to "connect the multi meter between the red and green leads at the potentiometer electrical plug"

do they mean the male end(goes into the plenum chamber) or female end?
i only get a reading of 175mV on the female end (suppposed to be between 290 - 360mV). i get no reading on the male end of the plug (well, = 1mV). how does adjusting the potentiometer at the plenum chamber affect the female plug readings??

very confused! thanks in advance...
-rob,
sandwich, MA

Terrys
10-28-2007, 05:49 PM
I ignore the voltage readings simply because they are what they are. If I suspect a TPS, connect the multimeter, in a low ohms scale to the TPS. I can't remember which colours are the terminal ends of the resistor and which is the wiper, but what you're looking for is a smooth needle deflection from low to high (or high to low if you're connected to the wiper and the high end) without any jumps or drops in the needle.
Digital VOMs are not neaqrly so usefull as a good old simpson 260 analog meter.
If you really must know the colours, I'll grab one from the junk box tomorrow and give them to you. There is only so much crap I can remember these days, and the TPS colours isn't one of them.

tz779
10-29-2007, 06:12 PM
I ignore the voltage readings simply because they are what they are. If I suspect a TPS, connect the multimeter, in a low ohms scale to the TPS. I can't remember which colours are the terminal ends of the resistor and which is the wiper, but what you're looking for is a smooth needle deflection from low to high (or high to low if you're connected to the wiper and the high end) without any jumps or drops in the needle.
Digital VOMs are not neaqrly so usefull as a good old simpson 260 analog meter.
If you really must know the colours, I'll grab one from the junk box tomorrow and give them to you. There is only so much crap I can remember these days, and the TPS colours isn't one of them.

thanks! the manual does say to check for a smooth swing of the VOM needle between max and min opening of the throttle. i imagine the connections are the same, red and green, but i'll use your's if they are handy....
BTW, i had the "gender" of the connectors reversed, but no matter, results are the same (no socio-political inferences here, either!).
-rob