1986 911 reference and speed sensor wiring

[pistolpete]

So I am putting back together a 1986 911 that I purchased in pieces. I have purchased new speed and reference sensors (the old ones were missing). I am familiar with installing them and setting them but I am puzzled by the location on the three hole bracket what goes where Does the speed sensor go in the middle hole or the reference sensor. Also is there any markings on the harness in the car to tell what goes where? Any help would be greatly appreciated.

[john walker's workshop]

The upper sensor goes in the lower hole in the bracket. DG tag may still be on the body side plug.

Edit, sorry, dg is on the middle one.

[emac911]

Do these help?

[pistolpete]

Yes that does help. I will check tomorrow for the dg tag. So that dg tag connects to the lower connector?

[emac911]

DG goes to MIDDLE

BG to lower

Heres a better picture

[pistolpete]

Well I checked this am and there is no markings on the harness in the car at all. So is there any other way to figure out which one is which?

[mysocal911]

Originally Posted by pistolpete

Well I checked this am and there is no markings on the harness in the car at all. So is there any other way to figure out which one is which?

Just try to start the engine. If it's a no-start, reverse the connectors.

[pistolpete]

Yes I guess that is an option. I was just trying to figure out if there was any way to know first.

[mysocal911]

Originally Posted by pistolpete

Yes I guess that is an option. I was just trying to figure out if there was any way to know first.

You can measure the AC voltage of each while cranking;

1. the RPM sensor is about 1.5 to 2.0 VAC, and goes to pins 8 & 27 on the DME ECM connector
2. the reference sensor is about .50 to .90 VAC, and goes to pins 25 & 26 on the DME ECM connector

It's that simple.

[pistolpete]

Thanks Dave