Tachometer Upgrade Issues

[red325ix]

I'm trying to swap a 7K tach into my VDO cluster for my 86 2.7i. I aquired a VDO 7k tach.

Upon disassembly I've found that the two tachometers look quite different. The DIY I read on strictlyeta.net said to seperate the tach from the econometer portion, and to reuse the original econometer. The original tach came out quite easy enough but I don't think that the replacement tach seperates the two parts. It looks like all one unit. And also the replacement tach doesn't have a coding plug on the econometer so I must reuse the econometer from the old tach. I know this has been done before so maybe I'm missing something.

Here are some pictures for reference. The 7K tach has pins on the side where as the 5k tach has pins on the top. The board inside of the original cluster looks like it has pins on the side and top.

Old tach on the right in all pictures.

[jlevie]

Swap the entire instrument (tachometer and econometer) as long as both are Motometer or both are VDO they'll work properly.

[Gregs///M]

OP, you can two completely different generations of tachs that you are trying to swap which are not compatible.

Your cluster, in the pic, is the 1982-1986 cluster. You need a tach from that generation. I believe I might have a tach with a 7k redline if you need one.

But yea, the tach you bought is for the 1986-1992 cluster, not compatible.

[red325ix]

OP, you can two completely different generations of tachs that you are trying to swap which are not compatible.

Your cluster, in the pic, is the 1982-1986 cluster. You need a tach from that generation. I believe I might have a tach with a 7k redline if you need one.

But yea, the tach you bought is for the 1986-1992 cluster, not compatible.

I'll take it. Pm me me payment info.

[Gregs///M]

I'll check my inventory to make sure, then I'll send you a message.

[red325ix]

OP, you can two completely different generations of tachs that you are trying to swap which are not compatible.

Your cluster, in the pic, is the 1982-1986 cluster. You need a tach from that generation. I believe I might have a tach with a 7k redline if you need one.

But yea, the tach you bought is for the 1986-1992 cluster, not compatible.

Still haven't gotten around to addressing this. Is a newer style cluster mostly plug and play if I decide to swap in a new one? Do the harnesses connect?

My build date is 1/86 but it somehow managed to get outfitted with the early style cluster. Obviously there were not m20b25's back then so the only 7k tachs I can find for an early cluster are from 318's. Will these work accurately?

[Gregs///M]

Still haven't gotten around to addressing this. Is a newer style cluster mostly plug and play if I decide to swap in a new one? Do the harnesses connect?

My build date is 1/86 but it somehow managed to get outfitted with the early style cluster. Obviously there were not m20b25's back then so the only 7k tachs I can find for an early cluster are from 318's. Will these work accurately?

Perhaps a Euro or Canadian model early cluster had the "i" 7k tach in it. I think you easiest course of action is to replace the whole cluster with a newer model 325i cluster.

[red325ix]

Perhaps a Euro or Canadian model early cluster had the "i" 7k tach in it. I think you easiest course of action is to replace the whole cluster with a newer model 325i cluster.

I think that is what I'll do. From what I understand I'll have to swap in my fuel gauge from the old cluster if I do that. I also think they use different style coding plugs and that swapping SI boards might be necessary, at least according to another old thread I dug up.

[Gregs///M]

The fuel gauge can swap but the SI board will not.