wiring a rev counter

[ScienceBoy]

Well, let's see what the weekend brings

[ScienceBoy]

ImageUploadedByTapatalk1393070465.562856.jpg

Dash pod off and looking for connections. Found them all including the green one indicated above. The flexi nature of the connections is a bit of a pain.

[ScienceBoy]

So it didn't go quite to plan. I connected up as below so I can test before siting. Before switching on I tested the lights, and the back light came on. However, when I started the engine the backlight came on (even though the light weren't on then) put the needle didn't move. Therefore I think my connections might not be correct (I'm assuming at the unit is in fact ok). Mind you, the instructions leave something to be desired.

Does anyone have a list of the pod socket connections?
Anyone suggest how I can confirm the green in the pod is indeed the pulse from the coil?

[1664]

VW wiring to Rev Counter is Green 0.5mm cable according to the Haynes and a couple of other sources.

Here's all the information I have at my disposal, apologies for handwritten scrawl

[ScienceBoy]

You're a saviour 1664. I thought the black wire to 8 would be ground. Doh! Let's hope I haven't screwed it.
So I've got the dash light feed and the tacho ok. I just need to "refine" my power and ground. :s

Looks like 12v feed on 6 and earth on 3?

[itchyfeet]

Get yourself a haynes manual, having a go at wiring with no wiring diagrams is going to get you into trouble sooner or later

[MidLifeCrisis]

Looks like 12v feed on 6 and earth on 3?

You don't mean pin 6 do you (that's the coolant sensor wire)??
12v looks like it's on pin 8!!!

[ScienceBoy]

You don't mean pin 6 do you (that's the coolant sensor wire)??
12v looks like it's on pin 8!!!

No you're right. I mean 8 (and that's where I've put it). Strange but the 6 doesn't go anywhere, even though there is a red/yellow wire in the plug. The temp gauge is run from 4?

[ScienceBoy]

SUCCESS!
Now to drill a hole and mount it...

[ScienceBoy]

Get yourself a haynes manual, having a go at wiring with no wiring diagrams is going to get you into trouble sooner or later

I think I'm fairly handy with electrics and electronics, but I hate Haynes circuit diagrams with a passion. The proper one 1664 supplied was much more to my liking. My problem yesterday was assuming black was earth, which is where the Haynes comes in handy, if you understand German words for colours! See I was thinking ac neutral as earth. Silly boy. Everyone knows grown is earth. Except in ac where it could be live...

:s

[1664]

Get yourself a haynes manual, having a go at wiring with no wiring diagrams is going to get you into trouble sooner or later

I think I'm fairly handy with electrics and electronics, but I hate Haynes circuit diagrams with a passion. The proper one 1664 supplied was much more to my liking.

That IS a Haynes wiring diagram

bl blue
br brown
ge yellow
gn green
gr grey
li violet (lilac)
ro red
sw black
ws white

E D I T: penny has just dropped, you meant the schematic diagram. I have a pdf of a VW instruction manual "How to read Wiring Diagrams". Even if you don't actually learn from it, it's a good reference. PM me your email address and I'll email it you if you like?

[willpom]

Once you 'get' the Haynes wiring diagram it is a piece of 'Fosters'. Admittedly it took me a couple of days studying and faffing behind the fuse/relay board and various switches to finally 'get' it!

[itchyfeet]

Nothing wrong with haynes diagrams imo, some people have difficulty reading them but thats probably because they dont understand electrics
i would have difficulty reading a book in a language i didnt understand

if you look at the hanes everything at the bottom is chassis ground and they are all brown
everything at the top are the power rails in the fusebox, you dont get told but its easy to see where they connect
30 is 12v
15 is ignition 12v
x is powered by the x relay that gets turned off during cranking to help starting
31 is ground

there are some others like
61 alternator charge light
1 tacho
b starter trigger wire
etc

every item has a code which you can find out what it is in the key
every wire has a colour which you can find out what it is in the key
where a wire goes to another page it stops with a box and you look for the number in the box at the bottom ground rail, these are in order so thats easy

[MidLifeCrisis]

Main problem with Haynes is that it is often just plain wrong!!
Much prefer the Bentley diagrams - much more likely to be correct, their wiring colour code abbreviations make more sense, and they name the items on the diagram (so it says 'Ignition Switch' rather than Haynes saying 'F31' and you have to go search to see what F31 is!!)

[Tufty_B]

...
30 is 12v
15 is ignition 12v
x is powered by the x relay that gets turned off during cranking to help starting
31 is ground
...

Not wanting to hijack the thread, but I'm also looking at fitting a tacho, can you explain in simple terms the difference between the rails 15 & x, I thought that 15 went dead during cranking?