PeachParts Mercedes-Benz Forum - View Single Post - Where is the RPM sensor on a W123 diesel?

pawoSD · #11 02-09-2006, 07:20 PM

I took my multimeter out to my cruise amp today, with the car running I get 14.12 volts in two pins of the socket that the amp plugs into, I get the same at the two pins on the back of the gauge pod in the dash. On the other holes in the socket (the ones from the pickup) I get no reading on any setting of my multimeter, nothing at all. Is there a way of testing the pickup to be sure its actually sending some sort of signal? It was said it emits a weak A/C current pulse....but I picked up nothing, not even in the hundredths of a volt....

The only way I could think of to test it is to have the stealership plug their "diagnostic" tool into the amp socket, as it reads RPM. If it showed no reading, I'd assume the pickup is the culprit, if it did, then something is screwy with my gauge, which is pretty much impossible.

Will this ever be solved? Who knows......any help?