1973 Merc control box, to a mid 80's box, 3 prong to 4 pin

[newuserguy]

Hi all.
I'm switching my control box from a 1973 box to a 1986(?) box. The old box has three prongs and the new has 4 pins. It is in the front of the box and I guess it has to do with supplied or received electricity to the key. Can I easily change this, re-solder? Thanks guys. My new manual (I'm a Johnson/Evinrude guy) is on the way via Ebay. Thanks for all the help.

 

[timmathis]

Re: 1973 Merc control box, to a mid 80's box, 3 prong to 4 pin

8)
Tim

 

[timmathis]

Re: 1973 Merc control box, to a mid 80's box, 3 prong to 4 pin

8)

 

[tashasdaddy]

Re: 1973 Merc control box, to a mid 80's box, 3 prong to 4 pin

i believe you are looking at the connection for a tach.

 

[ricksrster]

Re: 1973 Merc control box, to a mid 80's box, 3 prong to 4 pin

I aggre it is for the tach. The fourth wire will be for the warnibg horn.

 

[newuserguy]

Re: 1973 Merc control box, to a mid 80's box, 3 prong to 4 pin

I aggre it is for the tach. The fourth wire will be for the warnibg horn.

Got it fellas, Thanks for the help[ and keep up the great work. Jim