tachometer Install

[Brein]

Hello! I have a 518i with a clock instead of a tachometer, i bought a tachometer that came from annother 518i, but when i install it and starte the car, the needle goes to 7 k rpm and stops there, wondering if anyone knows how to retrofit one of these to my car?

[Aldo525]

Hello, I have an 83' 518i too with the big clock and installed a tacho plus econometer...tacho is working but no the econometer because my car is KJetronic so no ECU or signal to fuel consumtion. In your case the 518i is L Jet???.....and the tacho you purchase is just the instrument or a full instruments cluster???....I mean, maybe the tacho have not the "coding plug"....necessary to properly functioning of the tachometer.

[Brein]

I have bought just the tachometer without fuelcomsuption, my car has a carburetor so no fuel injetion, when i was instaling the tach i saw that there where two connectors behind the dash, a blue and yellow one, don’t know of this relevant but it was connected to the blue one and nothing in the yellow one, i think there is now rpm wire to the dash that is not connected, so i was thinking that i need too fine that and Connect it maybe?

[Aldo525]

I have bought just the tachometer without fuelcomsuption, my car has a carburetor so no fuel injetion, when i was instaling the tach i saw that there where two connectors behind the dash, a blue and yellow one, don’t know of this relevant but it was connected to the blue one and nothing in the yellow one, i think there is now rpm wire to the dash that is not connected, so i was thinking that i need too fine that and Connect it maybe?

Just the blue connector is fine. Yellow is used in cars with OBC, ext temp sensors, etc. Mine just have the blue connector. But still my previous question: have the tacho the coding plug???...in early cluster is a small black plastic piece with holes that is inserted by the rear bottom side of the cluster, normally one of its "legs" have some color like green, yellow, etc. Without that coding plug the tacho doesn't work. Can't add an image now to clarify this....

Have the tacho any sticker with numbers????....