1969 tachometer

[thor]

hello ,

my tachometer has been totally rebuilt on my 1969 2.0 .
engine is running well (new) but nevertheless the tacho does not answer.
it seems there is a problem between the CDS and the tacho (black purple wire)
i 've checked the wires and it is ok.
then there is still the small grey component (SCR switch ) between CDS and tacho. Can I directly take the CDS wire to link it to my tachometer and then bypass this component ?
is there a risk ?

thanks a lot

[304065]

Thor,

What model is your 69? I assume an E or S with factory CDI? Let's start with what you have, a photo would help, then we can get around to diagnosing the problem.

[thor]

Hello

It is a 69 e , i rebuilt my engine .
Tachometer was running well before and it is the original one.
May be the fact the car did not run during 5years it creates a defect .
Can i connect directly the tacho without problem just to see if it works like that . If yes it means intermediate unit is not working ....
The cdi is working well as the engine is well running

Jerome

[thor]

Any help please

[thor]

Is it normal to have a black purple wire connected to the mfi transducer
See my picture on the following link

electric question : 2.0 E engine compartment

[thor]

I mean before rebuilding my engine the tachometer was ok .
As i let the car few years in the garage before all was restored , may be time , humidity ....
Before re sending the tachometer to be rebuilt to bypass intermediate unit , i would like to be sure it is intermediate unit the problem. ....

[thor]

I've received my tach modified to bypass the intermediate unit.
i've wired the bk/pu wire to the distributor and at last it works ...
I let the intermediate unit in place to keep original but it was this unit which was faulty....

thanks all for your help

[gamin]

I wish that you had posted initially that your tach had been modified to bypass the "intermediate unit." I believe that the " intermediate unit" you refer to is in fact the ballast resistor mounted on engine electrical panel left rear. Silver cylinder bosch 0 227 990 001. Only used 69/70/71 to use older tachs with cdi ignition. With a newer or "modified" tach in order to make it work it is only necessary to remove the ballast resistor and then jumper wire from the distributor to the black/purple wire that was attached to the ballast resistor at terminal C. Your tach should then work. I just got through doing this on my 70.

[thor]

You are right.
I let this silver part on the panel but i ve wired the black purple to the distributor.

Jerome