Where does the purple/white wire go?

86metro

Cadet
Joined
Jun 4, 2010
Messages
10
I attempted to time my mercruiser 4.3 lx and was going through the steps and found that the purple/ white wire that your supposed to ground to put it into base timing mode was already undone. So is that how its always suppose to be and its only purpose is to be grounded when need be or does it actually connect to something else. Because the boats been running awful and im hoping that its just because the auto advance timing hasnt been working due to it being unplugged. So if anyone can shed some light on this that would be great.

Also I was going by the timing procedures for a Thunderbolt V ignition system. I figured that was what I had because it had a purple/white wire. Maybe its a Thunderbolt IV, I dont know. Its a 1997 Celebrity 180 with the 4.3 mercruiser lx gen+, serial # 0K160701
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Where does the purple/white wire go?

When the purple/white wire isn't connected to anything, it's not grounded. To ground it you have to attach it to a good clean ground. You will have to make a jumper wire to do that.
The wire when just laying there does noting, it's not grounded or anything. It just the end of a wire. Only when hooked to ground will it set your distributor into base timing mode so you can set and/or adjust your timing or adjust your carb mixture.
 

86metro

Cadet
Joined
Jun 4, 2010
Messages
10
Re: Where does the purple/white wire go?

Alright then, what I was wondering is, after I ground it and go through the timing steps what do I do with it after im done. When I found it, it was already unplugged. My question is,is it supposed to be plugged in when in normal operation? And if it is where and what does it plug into?
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Where does the purple/white wire go?

When you aren't grounding it for adjustments, then it just sets there, unhooked and does nothing. Stop trying to hook it to something and want it to do something. It doesn't do anything unless grounded.
 
Top