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Tacho and Shift light connection

Posted: Sun May 29, 2016 2:40 pm
by TaSmania
Guys. I have an S60 on my BMW E30, 325i but the taco drive using the wasted spark set up of the S60 means the tacho is not working. Any ideas on how to connect up the S60 to my tacho and will the ECU need to be set up?

Re: Tacho and Shift light connection

Posted: Sun May 29, 2016 4:20 pm
by stevieturbo
Dont understand the question.

Are you saying the tacho output from the ecu will not work with your tacho ? Or something else ?

Re: Tacho and Shift light connection

Posted: Sun May 29, 2016 10:36 pm
by Jon K
Confused by this also. Are you talking about an E30 that had its tach being driven by the dizzy/coil?

Re: Tacho and Shift light connection

Posted: Mon May 30, 2016 3:12 am
by TaSmania
Oops I hadn't intended the question to confuse. I have an S60 in an E30 325i - 6 cylinder. Therefore the DTA runs the ignition as wasted spark. Therefore I cannot use the cars original tacho drive. There is a tacho output on the DTA S60 which I'd like to use. Can it be connected to the cars standard tacho and if so how do I do it and does the DTA need to be calibrated?
There is also a shift light output on the DTA. How does this work?
Thanks

Re: Tacho and Shift light connection

Posted: Mon May 30, 2016 3:50 am
by Rob Stevens
The ECU's rev counter output can be configured in the software to simulate any amount of cylinders/pulses per rotation, find this in 'General engine settings 1' it is a square wave to ground output, some rev counters may need a pull-up resistor, I'm not sure about your bmw.

The shift light is usually a low wattage bulb on the dash and can also be set to come on at a chosen rpm. It can also be used to warn of other things like high water temp. the ecu switches to ground so you need 12v to the other side of the lamp. setting will be found in same general engine settings

Read the manual

Re: Tacho and Shift light connection

Posted: Mon May 30, 2016 4:37 pm
by JON-TEC-RALLYE
hello good night, it is very possible that the tacho oem e30 work with positive sign, the original ignition system amplifier leads to the coil, is contacting with dtafast, has a small circuit wiring with some diodes.

I installed some but for 4 cylinders. bmw e30 2002. I installed the dashboard not oem

Re: Tacho and Shift light connection

Posted: Tue May 31, 2016 3:04 am
by Alex DTA
If the tacho was originally driven by the coil, the ECU can't drive it. You will need to use the coil to drive the tacho.

See here:
http://www.clubgti.com/showthread.php?166151

Re: Tacho and Shift light connection

Posted: Tue May 31, 2016 12:57 pm
by ottotuning
The S80 in my e28 runs my rev counter directly wired to pin 2..