RobBrown
|
| posted on 28/3/03 at 01:34 PM |
|
|
Rev Counter
I have connected up my rev counter, as described in the installation instructions, but have come accross a problem, which seems quite fundamental.
2 of the wires into the unit are connected to the ignition coil (1 on each if the 2 terminals). However the wire which is connected to the -ve
terminal, according to the instructions, should also be earthed on the chassis. When I do this, and try to start the engine, the coil gets very hot,
and no spark is generated, thus the engine doesn't start
If I disconnect the ground the engine will start, however the back light on the dial remains on permenantly.
Thanks in advance. I'm sure someone out there knows how to solve this.
|
|
|
|
|
David Jenkins
|
| posted on 28/3/03 at 02:25 PM |
|
|
That sounds wrong!
In my car the +ve terminal goes to the ignition-switch and so is 12v.
The -ve terminal goes to the distributor and the sensor wire of my tacho. The distributor does its thing by periodically shorting this side of the
coil to the chassis, then disconnecting it, inducing a big fat spark at whichever plug is currently in-line.
This is why you should never leave the ignition switch on for a significant period without the engine running - if you are unlucky you can cook the
coil, just as you describe.
I recommend that you re-check the wiring diagram for the tacho! What make is the tacho? If it's a CA/Greengauges/Smiths one, then maybe I can
check on my wiring diagram.
cheers,
David
|
|
|
jonti
|
| posted on 28/3/03 at 02:28 PM |
|
|
If you ground out the -ve side of your coil then, when you switch on the juice to it the thing will be permanently 'on' instead of getting
switched by the points/electonics etc in the dizzy thus it gets hot and no spark.
Whithout seeing your tacho its difficult to say but all the ones I've ever seen have three wires +ve, -Ve and 'trigger' which
usually goes to the switched side of the coil. Thus every time a plug fires the tacho counts. Why your light is on is a puzzle unless you're
mixing up the backlight and trigger wires.
I concure with the comments of my honourable friend above.
[Edited on 28/3/03 by jonti]
[Edited on 28/3/03 by jonti]
OFROK
|
|
|
RobBrown
|
| posted on 29/3/03 at 10:49 AM |
|
|
I have got the original Sierra Ignition module in amongst it all as well. The -ve coil terminal also goes into the module, and 2 wires from the module
go to the distributer. The +ve does go to the ignition switch
The tacho is made by Smiths, and has 6 wires in all, of which not all are required (according to the instructions).
If I ground the wire, from the tacho, which is going to the -ve coil and disconnect it from the coil, this corrects the light problem, but I dont get
a reading on the counter, when the engine is running
I'll try connecting the -ve coil to one of the other wires to see if I get a reading.
Thanks for your help
Rob
|
|
|
theconrodkid
|
| posted on 29/3/03 at 09:06 PM |
|
|
the 2 - wires are earth,1 earths the unit through the ign and therefore counts the pulses the other makes the backlight work,thats my understanding of
it
who cares who wins
pass the pork pies
|
|
|
David Jenkins
|
| posted on 30/3/03 at 09:06 AM |
|
|
quote:
Originally posted by RobBrown
I have connected up my rev counter, as described in the installation instructions, but have come accross a problem, which seems quite fundamental.
2 of the wires into the unit are connected to the ignition coil (1 on each if the 2 terminals).
I have a Greengauges tacho, which I believe is identical to Smiths (only the labelling is different).
According to my instructions, if you ignore the lamp, there are only 3 wires to worry about:
green - to 12v supply (not coil!)
black - to earth
red/blue - to the -ve terminal of the coil.
The red/white is for the lamp.
This is for the usual electronic ignition or contact breaker ignition. If your ignition has an output for a tacho, then use the white/black wire to
that connection instead of the red/blue to the coil.
If you don't recognise these colours then you have something different, but I'd be surprised if it wasn't identical.
For more info look at http://www.greengauges.com/help/faq8.asp
cheers,
David
|
|
|
Peteff
|
| posted on 30/3/03 at 09:13 AM |
|
|
Thin green wire?
I used the Sierra ignition module and the dash dials and there is a wire from the standard wiring which goes to the tacho and back. I think it's
a thin green one and the dial has it's own feed from the ignition so the green wire is just a loop through and doesn't earth.
yours, Pete.
yours, Pete
I went into the RSPCA office the other day. It was so small you could hardly swing a cat in there.
|
|
|
RobBrown
|
| posted on 30/3/03 at 07:12 PM |
|
|
Those colours look remarkably simlar.
Why didn't the installation instructions just say that.
I'll give it a go.
Rob
|
|
|
