pulse signal

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bad driver
Posts: 207
Joined: 27 Jun 2003, 01:03

pulse signal

Post by bad driver » 17 Oct 2004, 01:47

anyone know how I can find a pulse signal on the 306 td?
basically the td engine is in a n/a derv, the n/a didnt have a tacho as standard and I got fed up off dodgy incorrect speedo on cable drive so I'm putting aftermarket gauges in but the tacho requires a signal, assuming the engine will be sending one as the dt had a tacho and they use the same loom. Also need to find out if it is 2 pulse??
Thanks
Richie

PowerLee
Posts: 1256
Joined: 01 May 2004, 19:49

Post by PowerLee » 17 Oct 2004, 01:56

Hi
It all depends what set of gauges your fitting to your 306.
There are several different options for a start, At least one of the diesel tachos works of the alternator terminal W, All the other diesel tachos work of a engine sensor, I think its the TDC flywheel sensor but dont quote me on that.
Also mid 1996 was the changover point for ditching the speedo cable for the electronic set up.

PowerLee
Posts: 1256
Joined: 01 May 2004, 19:49

Post by PowerLee » 17 Oct 2004, 02:01

Hi
I would look for a Brown 3 terminal plug near where the gearbox & engine are joined.
This is the flywheel sensor connection.
Have a search on the Citroen section for "Diesel Tacho" & that should point you in the right driection

bad driver
Posts: 207
Joined: 27 Jun 2003, 01:03

Post by bad driver » 17 Oct 2004, 02:26

Thanks for the quick response, I've had a look and search etc, anyway, I know of this TDC sensor, mine comes up to a 2 pin plug though?? Also I think it may need replacing as it appears to be dead as a dead thing. should it make contact with the flywheel? Mine seems to have a small gap between it and the flywheel. I'm also assuming as its a TDC sensor it will only trigger once per revolution when the engine is at TDC, any idea what would happen if I could make it trigger twice, the tacho requires a 2 pulse connection, which I am assuming means 2 pulses per revolution.

bad driver
Posts: 207
Joined: 27 Jun 2003, 01:03

Post by bad driver » 17 Oct 2004, 02:36

The alternator is a good theory, any idea what the ratio per revolution is on there? ie 2:1 ??

PowerLee
Posts: 1256
Joined: 01 May 2004, 19:49

Post by PowerLee » 17 Oct 2004, 15:01

Hi
The flywheel sensor should have a small air gap between the tip & the cars flywheel.
There are loads of small notches around the flywheel & one large notch, The sensor works just like a ABS sensor by sensing the notches passing under the sensor, The large notch is the reference one so the sensor knows when 1 complete revolution of the engine has occurred.
I do know that diesel tachos are different form petrol ones & cannot be swopped between cars.
I cant really help anymore on this subject, Im more of a petrol man.
Im sure somebody has done this before, good luck.