one weird stray wire location

[mastodon]

Hi,

I've had a 745 for about 3 months now and am trying to get my head wrapped around the thing. The resources online are very good be it electrical troubleshooting manual or FSM etc.

I have had no luck finding out what this wire is.

It comes out of the loom that has the injector wires between cyl 5 and 6. Brown/white or maybe brown/yellow with a spade female connector.

745 stray wire.jpg

The manual says something about a injector ground but I'm not convinced that this is it. The motor runs well with it detached but I don't like it floating in space. I have looked thru all the Bring a Trailer 745 listings to no avail and went to socal vintage in search but not a single 745 was in attendance..

Hoping for some luck here.

Best,

Matt

[mastodon]

I have some new info

test 14 seems relevant

745 temp switch.JPG


#8 on this diagram

temp switch 745.JPG

and lastly

745 stray wire2 .jpg

The sensor is on the motor but disconnected. I also don't know what connector type goes on it?

What does this do? It's apparently only on the 745 (S/CH models with EGR)

I have found little to no information on its functionality.

Thanks

[mastodon]

I have found my answer I believe.

Paired with above information,

http://repair.bmw-e23.com/pages/en/1....html#refertoc

This temp switch plus the speed sensor control when the EGR blower turns on/off.

[Hit Man X]

There is NO EGR on a 745. The information you found is wrong.

It is for an aftercooler blower fan to the turbocharger CHRA. That wire runs to the sensor and back to the relay on the driver side, by the strut mount.

After a certain set point of temperature, the sensor grounds and trips the relay upon shutdown.

[mastodon]

As an aside, the first picture on my second post is a screenshot out of the m106 repair files. Test 14 says something about egr right below the header. I agree my car has zero egr equipment and you know way more than I.

I do have all of the aftercooler blower fan and ducting and wonder why I don't hear it.. How long does it usually run on shutdown?

What does the factory connector look like for that thermoswitch?

Thank you!

[Hit Man X]

That engine is not an M106 nor an M102 in the attached photos, early M30 in the E23 due to the intake manifold design. Perhaps the EGR was for vehicles with thermal reactor manifolds, I have no idea as most have been converted to standard manifolds with detached catalyst. The female spade slides down onto the temperature probe and that is the factory connector. Reach up by the starter, grab it by the end, and slide it straight down. Once you figure it out, you will see how easy it is to install. Last time I recall mine working was about 90 seconds, maybe it was 60 (10/84 has been parked for a few years). The 11/84 745i I just acquired has a bad relay or bad constant 12V feed I need to address. The relay has a few ICs, two caps, and two transistors within Easy enough to rebuild or I sell them rebuilt. Tis easy to pin out the connector.

[mastodon]

Thank you!

I kindof thought that was a possibility but have never seen such connection in my time playing w/ bmw...

My car is an 86 745i and the motor/trans have not been removed in its life to my knowledge. The previous owner had it for 20+ years and owns LaJolla Independent.

I will be reaching out shortly, would like to chat.

Best

MP