Grounding cable to nowhere

[FastAndLight]

So, my e30 iX has sort of been a rusty mess.

I've been battling her back and have gotten a lot of it under control, however sometimes things just confuse me.

For the longest time I've had this grounding wire coming off the ground point in the engine bay by the suspension mount that just goes to nowhere. I finally took a picture of it today. I would love to know what it is supposed to go to.

[barbierij]

i dont think any of mine have that. ill check tomorrow. maybe the PO had something hooked up?

[barbierij]

So, my e30 iX has sort of been a rusty mess.

I'd like to see an iX that's not a rusty mess.

[FastAndLight]

I'd like to see an iX that's not a rusty mess.

Yeah, that would be nice. I wish I could just get over my love of all wheel drive, then I could pick up an iS and do some insane motor swap as opposed to constantly just trying to keep ahead of the iX's issues due to years of neglect and rust.

If you have a chance, I'm trying to track down all of the grounding cables.

I have replaced the one from the engine to the frame rail and the hood to the frame. Last night I tried to figure out where the rocker cover to frame was supposed to go and I think I've made something that will work.

I have cables for the AC compressor and.... something else. I can't remember what. Are there any other major ones I should be looking for / have rusted away leaving no evidence of their prior existence?

[wodcutr]

It attaches to the mesh wrap that surrounds the wires that go to the AC and into the fender for the abs. It is some kind of metal mesh so it is grounded. I have not seen it on any other e30 so I have no idea why it is needed and why ix's have it!

[dnguyen1963]

If you think about it, everything is grounded to the car chassis, right?

[vpilarrt]

If you think about it, everything is grounded to the car chassis, right?

Not from an electro-mechanical engineering standpoint. As designers of electro-mechanical equipment where I work we are prohibited from relying on mechanical joints for electrical grounding. Grounds must always be seperate and utilize heavy wire or, preferably, braded wire. Mechanical joints and attachments are often painted, sometimes move and may be of inadequate surface area to meet low resistance and possible high current requirements. Typical ground point resistance requirements are < .1 ohm. So, theoretically mechanical attachment points can act as ground paths but you can't rely on them.

[FastAndLight]

It attaches to the mesh wrap that surrounds the wires that go to the AC and into the fender for the abs. It is some kind of metal mesh so it is grounded. I have not seen it on any other e30 so I have no idea why it is needed and why ix's have it!

It should go without saying that I definitely don't have that...

I'm going to take a couple photos of the engine bay...
[edit]
Here are some photos:


A whole lot of no wire mesh thing:


Another shot of that side of the engine:

You can almost see my two new ground wires, one on the hood, one on the back of the rocker cover. I grounded it on the tray that the washer fluid reservoir sits on.

And then I noticed this...

So, I assume that black wire is supposed to go to the connector. I guess this explains my slightly erratic temperature readings. I think the black wire is just the sensor ground wire...but the green one looks like it is about to go as well. How should I go about repairing something like this?

I guess I need someone to cut me off one of the plugs from a parts car so I can splice in the wires...

[FastAndLight]

Ok, so that is the dual temperature switch and it appears that the black wire goes to the normal speed relay.

[barbierij]

here ya go. from the '89ix. 433k on this one.







sorry i forgot to get the pic to you. i didnt even check the other two.

[FastAndLight]

Thanks, I appreciate it. I definitely don't have any of that copper mesh. That said, my noise issues in the radio have gone away, but I'm still having a really strange intermittent starting issue. Sometimes if the car is hot and I try to start it more than 10 minutes but less than 2 hours later, the starter won't crank. Once it cools it starts every time. I don't want it to be the starter because that will be a huge pain in the ass, but at this point, I don't know what else it could be. The battery is brand new and I've replaced the main engine grounding cable.

[AndrewBird]

Sounds like the starter gets hot and stops working. When hot, can you shut the car off and re-start it immediately?

[FastAndLight]

Sounds like the starter gets hot and stops working. When hot, can you shut the car off and re-start it immediately?

Yes, immediate restarts are fine. I can stop for gas, use the facilities, and get back to the car and it cranks and starts just fine.

If I stop, browse around Harbor Freight, find something, wait in line, get back to the car, and it won't crank. Wait another 30 - 40 minutes, the starter fires just fine.

Sometimes even when cold there will be a bit of a pause before the starter cranks.

The car starts every time the starter goes, it is just getting the starter to fire.

I really appreciate the help.