rev counter

bonkeye · Post by **bonkeye** » Sun Sep 06, 2009 9:00 pm

how do i convert the signalfrom the MJ to work with the factory rev counter in my car

thanks

NITROPIXIE · Post by **NITROPIXIE** » Sun Sep 06, 2009 9:01 pm

what car?? is it a saxo by any chance???

bonkeye · Post by **bonkeye** » Mon Sep 07, 2009 8:01 pm

AX GTi mate
but it has a saxo VTS engine

bonkeye · Post by **bonkeye** » Mon Sep 14, 2009 7:47 pm

anyone have an idea on this?

Post by **brentp** » Mon Sep 14, 2009 7:58 pm

The V4 controller outputs a 12V square wave for the tach signal. This works with many tachometers. There are other techniques for driving your tachometer, in case this signal is not compatible, see here:
http://www.autosportlabs.net/MJLJ_V4_ve ... achometers

adsport69 · Post by **adsport69** » Mon Sep 14, 2009 8:52 pm

If your AX GTI is anything like my 205, bearing in mind Citroen and Peugeot share technology, you might have to modify your tacho to accept the 12v pulse from the Megajolt.

This has been mentioned in another post (I am cheap and cheerful), but I removed the first two components in my tacho a resistor and a capacitor i think, and bypassed them, done this on three 205 gti tachos and they all work with the Megajolt 12v pulse. I decided to take a photo of the one I did this week and tested - worked fine.

I suggest you get a set of spare ax gti clocks and have a go at modding them, if you have MJ installed on your car you could try the VRSSIM to test it all - I always use it for testing Megajolt Installs.

Post by **brentp** » Mon Sep 14, 2009 9:33 pm

^^^ Thank you for the insight!

bonkeye · Post by **bonkeye** » Tue Sep 15, 2009 3:57 pm

havent bought the MJ yet as i ordering it at the end of the month just thought id get as much info as posible

i'll have a look on the internet & see what signal they take

parky1972 · Post by **parky1972** » Wed Dec 09, 2009 6:19 pm

I don't suspose anyone has any information on getting a rev counter working on a Mk2 Fiesta?

My gauge used to work on the old CVH I had in.
I've been told that the Megajolt feed doesn't work on these, so I got the Zeners and tried it that way. This works very intermittintly.
Now either, my gauge is fried, my wiring is bad or it just doesn't work with the Fiesta gauge.

Anyone got any advice?

Jason.

NITROPIXIE · Post by **NITROPIXIE** » Wed Dec 09, 2009 6:32 pm

Other options are:

to try pin 11 on the EDIS module, this is the Clear Tacho Out (CTO) pin. I think you only get these on EDIS 4's.

test the diodes are connected up correctly.

Did you use 3 or 2 diodes?? If 3 you could omit the third one and see if this helps.

If all else fails then you may need to mod the tacho itself. If you can get a pick up of the circuit board on the back i may be able to work out the circuit.

Autosport Labs

rev counter

rev counter

Not sure if this helps but.........