Rev Counter Wiring - MerControl

[cieranc]

Hi all, what ye all been up to this weekend? I've been mostly scratching my head about how to wire a Tacho up. The gauge is fitted into the dash of my Fletcher Arrow, but not wired up. Do I look for terminals on the engine to wire it into, or is this what the three pin socket on the front of the control box for? Is there a special cable available to fit in here or should I just crimp spade fittings onto a cable and push them in? As always, any advice would be much appreciated.....

 

[studgies]

If it's a petrol the tach is normally fed from the switched side of the coil.

Hope this helps.

 

[cieranc]

Sorry guys, its a Mercury 500 Blueband, 50hp fourstroke with the Thunderbolt ignition. Its got a plug on the front end of the control box, but I'm unsure what this is for. Also, in what way do speedo's normally work, as again there's one fitted but not connected. Does this run off the engine?

 

[spannerman]

There should be a socket or short length of cable with a socket on the control box depending on how old it is, this will have 3 connections, the grey cable if visible is the signal for the tach, the other two are + and -
On a fourstroke the signal is from the ignition system on a twostroke it is from the charging coil usually taken from one side of the rectifier again a grey cable.
If its an older motor then the 500 Blueband is a twostroke.

 

[cieranc]

Cheers Spannerman, I've been told on this site that its a 1973 going off the (Belgian) serial number 9007542. Its a four cylinder model, with electric start. I havn't run it for more than a few seconds at a time as I have no muffs for it yet, but it didn't sound like a two stroke. The control box does have the three pin plug on the front.