89 325i wiring mixup

[jeffie8696]

Going through the wiring diagram last night I noticed the engine speed sensor and cylinder ID sender signal might be mixed up. What would this cause the engine to do if anything? Both connectors are located on the drivers side front of the engine below the intake and are the same connector for both. I believe the wire colors are the same for both.

[marti5]

Well one answer to that then! if you think they are incorrect swap them over, although over the years they have been there, the loom would have taken its shape, so if you take one off and it flicks to the left or right, you will then know there wrong!

[jeffie8696]

I just had this engine installed by a less than stellar mechanic. Long story. I have had issues since then. I have had to fix his repairs several times.

[marti5]

Ok, so hows the engine running ? and have you changed the wires over ?

[jeffie8696]

I just got back from under the hood. I see that the connectors are a one up one down arrangement, hopefully BMW would have no reason to change it for whatever reason. I did unplug the throttle position switch/sensor and it made no difference, funny since I just installed a new one last year. I will be looking into it when I get my multi meter back. Could be the wiring harness from the new engine has a break in it inside the loom.

[silversled]

I would personally not go changing wiring around on an 89 325....gotta be something else and messing with the wiring (unless its' already been compromised) is not good....best of luck

[jeffie8696]

Thus my problem. I purchased this used engine from a HACK ,so called mechanic and he replaced the wiring harness with the one from the other engine. I have no idea what year the "new" engine is (or anything else for that matter) and he insisted that he install it to give any kind of warranty. so now I have a lot of money stuck in a "new" engine that I would have been better off replacing myself. In fact I had to make repairs to his handy work before I drove the car away from his shop!! And even then I didn't get one block away before I realized the windows wouldn't roll down!! Back to the shop and have him repair that (which he didn't admit he screwed up).

[witeshark]

Did you check the window circuit breaker switch on the center console to make sure about the windows?

[silversled]

yeah, that sounds like an issue..hmmm....what are you thinking of doing about this? inquiring minds want to know....kidding of course....good luck

[marti5]

You really need to find out what year that engine is for future reference, as you may need a new part at sometime, sounds newer or could even be older if he had to change the wiring loom.

If you knew the engine year, that would be a good start as then you could cross examine the two loom diagrams to see whats different.

[jeffie8696]

I am still thrashing the electrical problems. Just had to replace the wiper motor because it got so hot it melted the plastic cover and made the car STINK like you couldn't believe. I have been avoiding driving it since then for obvious reasons. (need to check the fuse size obviously)
I see the ground for other parts of the loom is orange/brown and that is the #2 wire on the connector that is supposed to be ground. But I am still confused as to why I would be seeing battery voltage at #1 and #3. since according to the Haynes it is supposed to be only 5volts.
Next I will remove the computer connector and test #52 and #53 for proper voltage. I can only speculate that for some reason there was a change in the design and they used a resistor in the ground for the TPS and used battery voltage for signal.
I would love to identify this engine but the Hack and I have fallen out and I do not speak to him.

[jeffie8696]

Well I retested the wiring again. This time the center plug on the 3 pin connector shows a good ground. Obviously the wire has an intermittent ground. So I will be running a new wire to it. I still can't explain why the other pins show battery voltage.