Next, we continue the ETK_61 section General electrical equipment of the vehicle
Next subsection Wire bundles (Battery)

On all diesel and top models of the E30, the battery was located in the right niche of the trunk - for better weight distribution between the axles.
My car also had it in the trunk, but it wasn't done quite right. The "plus" terminal was not screwed in its place, but on the platform for the battery under the hood, the "minus" terminal was also not screwed to the rear fender, but to the rear bumper attachment, and the battery itself in the niche was not fixed in any way and just lay there on a piece of paralon and a cover that goes over the tank. Of course I fixed it all and made it the way it should be. Everything was cleaned, fasteners were galvanized, what was missing was replaced with stainless steel.

Parts Home and Forum are not used, they are for cars with a battery under the hood.
The set includes the main cable with a thin duplicate wire (#3), cable to the starter (#4), "minus" terminal (#5), "ground" wire to the engine (#6), terminal bracket with a cover (#7- 9), M6 fasteners for the internal hexagon (#10, 11), plastic protective cover (#12), rubber sleeve (#13) and 50A fuse (#14).
The ETC diagram does not show the attachment of the terminal bracket - three M6 bolts with nuts and washers, the attachment of the "minus" terminal and the "ground" wire - an M8 bolt and nut with washers.
So, let's start with the front. We treat the hole for the cable with wax, and install a rubber sleeve (#13) together with the cable (#3) into it. The terminal bracket (No. 7-9) must be installed after installing the noise insulation of the motor shield. It is also important not to forget to insert three M6 bolts into it first. I forgot. :) I had to unscrew it. The bracket is attached to the holes with two bolts under the internal hexagon and nuts on the other side (No. 10, 11).


A duplicate thin wire is screwed to the upper pin, and the main cable is pressed to the two lower ones.

By the way, the thin and main cables are parallel and come from the same terminal. The 50A fuse (No. 14) is located only on a thin wire - in its rear part, under the casing.

We screw the cable to the starter (#4) to the terminal of the main cable (#3)

We put a plastic cover on the terminals and close it.

That's all under the hood at this stage.

The starter cable has a protective corrugation - check its condition.

In the cabin, we lower the cable to the threshold and lay it along the threshold to the back seat.



Under the rear seat, the cable runs between the body and the pipe for the tank ventilation pipes. A protective corrugation is installed in this place - we check its condition.

Of course the cable will be secured with clips and clamps along with the other wiring after it is installed.
Through the hole in the partition, we lead the cable into the trunk. There it is covered with a protective plastic cover (#12). The cover is inserted into the opening of the partition, and in the rear part is attached to the body pin. It will later be secured with a plastic nut along with the arch guard. This will be discussed in the next post.

The "minus" terminal is screwed to a special bracket on the rear wing.

Everything is ready to install the battery.
The "minus" wire to the engine remains. We screw it to the bracket of the left spar.

I restored mine. He looked like this.

Sanded, covered with zinc and replaced the heat shrink.

By the way, about the "minus" wires - somewhere on the Internet I found a reasonable photo of all of them with a description - thanks to the author.
Here are a bunch of other ground wires that you should also replace while you're at it. In general, you can use any thick wire with a suitable mounting hole, but for those purists at heart:

12-52-1-285-011 Alternator ground cable, however I used it to ground the A/C compressor to the engine block.
12-52-1-312-124 Generator mass cable (red).
12-51-1-714-039 Grounding of the engine to the frame.
65-31-1-286-069 Rocker cover, but instead I used 12-42-7-551-714 with e9x because of the factory 90* bend. Also, it looks a lot nicer =).
12-61-1-311-511 Oil level sensor mass. It attaches to the oil pan which simulates the oil level as our machines do not have a sensor. (for boys m3/s14).
65-31-9-055-973 Radio-protective grounding tape.
65-31-1-286-068 Hood grounding belt.
12-42-7-551-714 from e9x which I used as ground to cover the rocker instead of the ugly 65-31-1-286-069 cable.

12-52-1-285-011 Alternator ground cable, however I used it to ground the A/C compressor to the engine block.
12-52-1-312-124 Generator mass cable (red).
12-51-1-714-039 Grounding of the engine to the frame.
65-31-1-286-069 Rocker cover, but instead I used 12-42-7-551-714 with e9x because of the factory 90* bend. Also, it looks a lot nicer =).
12-61-1-311-511 Oil level sensor mass. It attaches to the oil pan which simulates the oil level as our machines do not have a sensor. (for boys m3/s14).
65-31-9-055-973 Radio-protective grounding tape.
65-31-1-286-068 Hood grounding belt.
12-42-7-551-714 from e9x which I used as ground to cover the rocker instead of the ugly 65-31-1-286-069 cable.









































































































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