300SD Intake sensor?
 

What exactly does that sensor do? Does it somehow tie in with the ALDA overboost circuit? The wire coming from the sensor looks like it goes into the loom behind the IP, which looks to be running in with the glowplug harness or am I seeing things? I removed the sensor from the intake while I had it off to clean out the Intake. Lots of guk from 28 yrs of driving and 300,000 miles. If you haven't cleaned yours out, be prepared for a lot of soot and oil mess. The best was to get all of it out of the inside would be an ultrasonic cleaning tank. I don't have one so I used our H.P. solvent tank, even then I still had to use a long tiny wire brush to try and dig all the soot and grime out.

Thanks!

Ya, that's the overboost protection sensor. When boost gets to around 15 PSI it grounds, closing the overboost protection valve.

-Jason