OBC alarm and relay box location?

[guibo09]

Im attempting to retrofit a COMPLETE obc into my 325is. I would like to know where the original location is for the

- relay box #7
- alarm horn in the engine bay #20-24
- where the alarm horn wire harness connects #25-26



edit: can someone confirm that the 6 button OBC temp sensor and wiring are the same?

[James Crivellone]

Im attempting to retrofit a COMPLETE obc into my 325is. I would like to know where the original location is for the

- relay box #7
- alarm horn in the engine bay #20-24
- where the alarm horn wire harness connects #25-26



edit: can someone confirm that the 6 button OBC temp sensor and wiring are the same?

The Relay unit is under the dash, on the upper portion fo the inner firewall, big, black, 2 green connectors, you can't miss it.

The horn on the earlier models was right next to the fuse box, and near the other horns on the late models.

The temp sensor is the same, and uses the same extension harness across all models and trim levels.

[guibo09]

thanks for the thorough response.

do you happen to know if it's on the right or left side for the late model? i have a horn on both front lower corners.

[James Crivellone]

thanks for the thorough response.

do you happen to know if it's on the right or left side for the late model? i have a horn on both front lower corners.

its a 3rd horn, and I don't recall its exact location.

Note the horn is really only used for the CODE function, which pretty much nobody ever connects or uses.

[guibo09]

its a 3rd horn, and I don't recall its exact location.

Note the horn is really only used for the CODE function, which pretty much nobody ever connects or uses.

i know what it's for, and i count on using it.

[guibo09]

okay can it be that post 87 cars dont have the 3rd horn and just use the regular 2 horns? i just searched the entire engine bay of a 1987 IS and did not find the dam horn. the two regular horns were there, but nothing else.