NO power to body but battery has 12v power

[pofo]

Well I'm having an issue with my engine starting to brake up and loose power all together. So I was trying to figure out if I had an ecu issue or grounding issue. But now I am not getting any power to the body of the car at all. But I have power from the battery to the engine and also power at the fuse box. My guess is ground issues might be linked. I do randomly get power to the cluster and then when I try to turn the car over I hear a bang sound and I loose all power again. Has anyone had this issue of loss of power? My battery ground tests ok and same with the engine ground. This issue started on a track day middle of the day unfortunately, but was able to limp the car home.

[epmedia]

The car chassis/body needs a very good ground, and same gauge wire just like the engine ground requirements.

Some items that use chassis/body ground are: fuel pumps, lights, hvac blower motor, aux cooling fan, etc.. almost everything that's not attached to the engine. Lambda and ICU grounds 'originally' attach to the engine.

In case needed:

1981-1983 pdf file, electrical manual
http://www.findmymerchant.com/images..._1981-1983.pdf

[pofo]

The car chassis/body needs a very good ground, and same gauge wire just like the engine ground requirements.

Some items that use chassis/body ground are: fuel pumps, lights, hvac blower motor, aux cooling fan, etc.. almost everything that's not attached to the engine. Lambda and ICU grounds 'originally' attach to the engine.

In case needed:

1981-1983 pdf file, electrical manual
http://www.findmymerchant.com/images..._1981-1983.pdf

Thanks I am going to check over my grounds tomorrow. I'm hoping something rattled it's self loose.

[tlapham]

Sounds like either poor connections on the battery terminals or bad ignition switch.

[pofo]

Sounds like either poor connections on the battery terminals or bad ignition switch.

Wish it was as easy as the battery. I have relocated the battery to the rear and I have 12v at the batter, starter and the stud in the fuse box. But I dont have power at any of the fuses and no power at all in the car. It sounds to me as if it is a ground connection but I am so busy with work I dont have time. Hopefully this weekend I will have time if it does not rain.

[320iAman]

Could be either one..Power or ground missing,,no power to instrument cluster does sound like ignition switch..

Randy

[pofo]

I have no power in the car at all - dome light, cluster, pretty much everything is with out power. It could even be a bad relay and also a ground issue. I just need to take time and look into the wiring diagrams. Just seeing if anyone had this issue or could point me in the right direction as to where the power is distributed from. If I remember correctly the grounds are near the headlights and all the connections happen in the fuse box. But idk if that is correct.

[epmedia]

With your battery in the trunk and if you used one of the studs on a strut as your chassis/body ground - this becomes a highly probable grounding problem.

[pofo]

I made a battery brace for the strut towers that the battery sits in and then welded a stud to the body for the ground. I also double checked this with my volt meter

[Somjuan]

Actually, did you check the fusebox to engine harness? Sounds like it might be loose.

[pofo]

Actually, did you check the fusebox to engine harness? Sounds like it might be loose.

I do think the fuse box is part of the issue.

[autox320]

I do think the fuse box is part of the issue.

I just did similar on an e30 sorting grounding issues. There is a lug main connection for the fuse box check that. Also just cause battery cables look and measure ok with a meter doesn't mean they are good. This stumped me until I took one off and wiggled the ends really pry it back. Found the end was just a few strands making connection not enough for high current or recharging the battery.

Another was the engine to frame ground wire make sure it's not corroded inside just cause looks ok. Ends clean metal and frame connection.

Lastly the starter takes a brunt of juice when hit the key. It's grounded through the block, which is why on the build car I added a cable to the starter mount point. Joined to the frame ground giving it a clean path along with the alternator ground.

These cars are old so this stuff is gonna pop up and annoy you.

[pofo]

I just did similar on an e30 sorting grounding issues. There is a lug main connection for the fuse box check that. Also just cause battery cables look and measure ok with a meter doesn't mean they are good. This stumped me until I took one off and wiggled the ends really pry it back. Found the end was just a few strands making connection not enough for high current or recharging the battery.

Another was the engine to frame ground wire make sure it's not corroded inside just cause looks ok. Ends clean metal and frame connection.

Lastly the starter takes a brunt of juice when hit the key. It's grounded through the block, which is why on the build car I added a cable to the starter mount point. Joined to the frame ground giving it a clean path along with the alternator ground.

These cars are old so this stuff is gonna pop up and annoy you.

I just did an S52 swap so all the ground wiring is new 2 gauge wire and the positive cable is also new OEM e36 battery cable I ordered from BWM. Im guessing its something that came loose or bad wiring in the fuse box. This happened while I was at the track so I am thinking something vibrated loose from turning in hard or maybe just from vibrations.