Unknown Electrical Connector under Hood

starcms · 11-07-2009, 01:39 AM

I was replacing my heater control valve today and some vacuum hoses, and I noticed an odd looking electrical connector under the hood. It's below the master cylinder and was hanging and leaning right against where the fender meets the firewall.

It measures 0V on ACC and 1.5Vish on ON. The connector is solid black rubber, round at the top with the two prong connectors as on a typical car fuse and narrowing down towards the bottom and goes into the wiring harness entering the cabin by the master cylinder. Everything electrical on the car works and it runs great (for now lol). What is this for? Maybe for an auto tranny?

Sorry for no pics. Its a US '78 928.

76FJ55 · 11-07-2009, 02:07 AM

Maybe the plug for the brake pad wear indicator. It is round with two blades on it. the sensor then has the two female blade connectors that plug onto it. there is a clip on the back side of the shock tower that it should be mounted in if that is what it is. the easiest thing would be to trace the wires from the brake pad sensor and see if it is connected.

starcms · 11-07-2009, 03:31 AM

That must be what it is. The P.O. told me he had "cut" all of the brake pad wear sensors and I had never noticed them any sensors nor any electrical wiring around the calipers.

Since the plug is there (assuming the other 3 are there too), could new sensors simply be installed or are more parts needed?

joejoe · 11-07-2009, 11:18 AM

just need the new sensors,

ZEUS+ · 11-07-2009, 04:10 PM

What color are the wires ? Is the brake pad warning light on ?

76FJ55 · 11-09-2009, 12:05 PM

The pad wear system would have to have been shorted somewhere to keep the indicator light from being lit continuously. If you find where the PO shorted the system you should be able to revive it by undoing the short and adding the pad sensors back into the system.

11-07-2009, 01:39 AM	#1
starcms User Join Date: Jul 2009 Posts: 7	Unknown Electrical Connector under Hood I was replacing my heater control valve today and some vacuum hoses, and I noticed an odd looking electrical connector under the hood. It's below the master cylinder and was hanging and leaning right against where the fender meets the firewall. It measures 0V on ACC and 1.5Vish on ON. The connector is solid black rubber, round at the top with the two prong connectors as on a typical car fuse and narrowing down towards the bottom and goes into the wiring harness entering the cabin by the master cylinder. Everything electrical on the car works and it runs great (for now lol). What is this for? Maybe for an auto tranny? Sorry for no pics. Its a US '78 928.

11-07-2009, 04:10 PM	#5
ZEUS+ Addict Rennlist Member Join Date: Aug 2006 Location: Manchester,NH Posts: 1,128	What color are the wires ? Is the brake pad warning light on ? __________________ 1988S4 Auto w/89 low gear trans, LSD, X-Pipe, RMB, AFPR, AAchips, 18's 1984S 5spd Drove it hard,now with Juvius ASE Master Technician Associates in Automotive Technologies, NHTC 1983

11-07-2009, 02:07 AM	#2
76FJ55 Addict Rennlist Member Join Date: Nov 2008 Location: Tulsa, OK Posts: 106	Maybe the plug for the brake pad wear indicator. It is round with two blades on it. the sensor then has the two female blade connectors that plug onto it. there is a clip on the back side of the shock tower that it should be mounted in if that is what it is. the easiest thing would be to trace the wires from the brake pad sensor and see if it is connected.

11-07-2009, 03:31 AM	#3
starcms User Join Date: Jul 2009 Posts: 7	That must be what it is. The P.O. told me he had "cut" all of the brake pad wear sensors and I had never noticed them any sensors nor any electrical wiring around the calipers. Since the plug is there (assuming the other 3 are there too), could new sensors simply be installed or are more parts needed?

11-07-2009, 11:18 AM	#4
joejoe User Join Date: Oct 2006 Location: Porterville, Ca. Posts: 331	just need the new sensors,

11-09-2009, 12:05 PM	#6
76FJ55 Addict Rennlist Member Join Date: Nov 2008 Location: Tulsa, OK Posts: 106	The pad wear system would have to have been shorted somewhere to keep the indicator light from being lit continuously. If you find where the PO shorted the system you should be able to revive it by undoing the short and adding the pad sensors back into the system.