Can I swop/upgrade the Instrument Panel ?

31st March 2009, 20:33

Hi

My son is really pleased with his 1.1 Saxo LX S reg but he'd like a rev counter(tachometer). Currently his instrument panel has a Speedo and clock.

Does anyone know if it's possible to just swop the panel for one with a tachometer ? Or is the wiring loom different for models which have a tachometer?

Or ss it easier to just buy an aftermarket tachometer and wire it up separately ... if so ... how do I do it ?

Any advice, however small, would be gratefully received.

Many thanks

Neill

31st March 2009, 20:37

get an aftermarket one, saves alot of hardwork mate.

Instructions on wiring will come with it.

31st March 2009, 20:50

I was wondering if that would be my easiest option ... ok I may go down that route.

Many thanks

31st March 2009, 20:54

Hi Neill,

I was randomly looking at the wiring diagrams for the saxos a few weeks ago (can reference it from a Haynes Manual if you want

) - due my car being part of the Predator ECU development, I was surprised at the time (among other things) that the SPI's (Single Point Injection) model (i.e. the early saxo 1.1's) had an output for the tachometer from the ECU.

Basically because the fuel injection system needs to know the engine speed in order to supply fuel correctly, there is always an engine speed sensor on the vehicle. This sensor goes direct to the ECU and then on the later models is outputted from the ECU to the dash. But apparently there is a tacho output on the 1.1 SPI ECU, pin 6. How easy it is to replace the clock and wire is beyond me I'm afraid!

You can use an aftermarket Tachometer as well... this is fed off the ignition coil (as opposed to the speed sensor). But I'm sure there's a few cases where the aftermarket tachometers show double the actual rpm of the engine... but can't remember the thread(s) of where that has happened!

Good luck.

Ads

31st March 2009, 20:55

there are some good buys on ebay as well

31st March 2009, 20:59

There is a guide for this somewhere.. ill have a hunt around.

31st March 2009, 21:32

Is this the sort of after market tacho which would work well with the Saxo?

http://cgi.ebay.co.uk/ws/eBayISAPI.d...link:middle:uk

31st March 2009, 22:04

Hi Ads
I've looked at the Haynes wiring diagram and see there's two wires from the engine speed senor (Brown and Green) (wherever the speed sensor is located God only knows)to the ECU. If I was to connect an aftermarket tacho do you know which wire would provide the engine speed (revs)? Or should I try the ignition coil instead ... if so again do you know which wire would provide the speed (revs) output?
Neill

31st March 2009, 23:29

I cant seem to find the thead.. but you can put dials from a VTR into a 1.1 and get the rev counter working but i do remember them running a wire from the ECU to the dials.

If you are going to put in an aftermarket rev counter I would defo look into getting a A-pillar gauge holder for it and getting one that fits into it to keep it subtle.

31st March 2009, 23:37

Good point about the A-pillar mounting ... had a quick look around and they do seem to be a nice and neat addition to the car.

1st April 2009, 00:06

Quote:

Originally Posted by Neill

Hi Ads
I've looked at the Haynes wiring diagram and see there's two wires from the engine speed senor (Brown and Green) (wherever the speed sensor is located God only knows)to the ECU. If I was to connect an aftermarket tacho do you know which wire would provide the engine speed (revs)? Or should I try the ignition coil instead ... if so again do you know which wire would provide the speed (revs) output?
Neill

Neill I wouldn't connect the aftermarket Tachometer directly to the speed sensor, it won't work and it'll limit the signal and induce noise to the ecu resulting the engine running rubbish in all likelihood

Additionally because engines/manufacturers use different speed sensors and as a result have different outputs to the ECU, making an aftermarket tachometer that ran directly off the speed sensor to suit all possible engines would be non-viable commercially, therefore they use the ignition coil as it's a much more consistent method across various engines. Similarly the output of the ECU to the standard tachometer is usually a bizarre output which an aftermarket tachometer has no hope of operating from

I've never done such a modification before but looking at the Haynes again (Diagram 4) you should probably connect it to Pin 3 of the Ignition coil (#36). Also you can see that the Ignition coil (#36) operates a dumb spark system (i.e. sparks on the induction stoke as well as the combustion stroke, which means four sparks per revolution as opposed to only two being needed (I think this is why most people who've done this modification find that the rpm is displayed as doubled what the engine speed actually is). If this happens just flick the switch on the aftermarket tachometer to 8 (options will be 4, 6 or 8).

Hope that helps!

ads

1st April 2009, 09:52

Many thanks for the advice about not connecting to the ECU ... I never thought about the consequences of interfering with the signal output.

I think I'm going to have a bash at this one.

and as you suggest go for pin 3 of the ignition coil. It'll be fun trying and help my son (and myself) understand a little more about the workings of the car.

Thanks again

Neill

1st April 2009, 10:53

if you want to do it quick and easy ebay is the best option

1st April 2009, 11:08

ebay it lol will be alot easier

31st May 2009, 15:53

[QUOTE]Neill I wouldn't connect the aftermarket Tachometer directly to the speed sensor, it won't work and it'll limit the signal and induce noise to the ecu resulting the engine running rubbish in all likelihood Additionally because engines/manufacturers use different speed sensors and as a result have different outputs to the ECU, making an aftermarket tachometer that ran directly off the speed sensor to suit all possible engines would be non-viable commercially, therefore they use the ignition coil as it's a much more consistent method across various engines. Similarly the output of the ECU to the standard tachometer is usually a bizarre output which an aftermarket tachometer has no hope of operating from

I've never done such a modification before but looking at the Haynes again (Diagram 4) you should probably connect it to Pin 3 of the Ignition coil (#36). Also you can see that the Ignition coil (#36) operates a dumb spark system (i.e. sparks on the induction stoke as well as the combustion stroke, which means four sparks per revolution as opposed to only two being needed (I think this is why most people who've done this modification find that the rpm is displayed as doubled what the engine speed actually is). If this happens just flick the switch on the aftermarket tachometer to 8 (options will be 4, 6 or 8).[QUOTE]

when you say pin three on the ignition coil which colour wire is this?
thanks