Trim limit wires...no where to be found

Searay D

Petty Officer 3rd Class
Joined
Nov 7, 2013
Messages
76
Hi Everyone
I could use a little advice please...I changed the Trim limit and sender switches on my 1988 Searay 230 Weekender with 7.4 Bravo....When I followed the lines into the boat the Trim limit wires were not plugged in...just dangling...which would explain no up on my trim....Ive looked everywhere and can not locate where they plug in...the schematic says to engine harness but there are no plugs anywhere....I'm beginning to think someone monkeyed with the harness prior to me owning....The wiring looks as if its been worked on....everything else works fine...I'm just finishing engine alignment so manifolds are off and visibility is as good as its going to get but I cant find the plugs...does someone have a picture they could share or detailed instructions...The schematic didn't help at all.
Thanks D
 

bspeth

Senior Chief Petty Officer
Joined
Aug 30, 2013
Messages
756
Re: Trim limit wires...no where to be found

check the wiring coming from the trim pump,I think that's where my were disconnected.
 

Searay D

Petty Officer 3rd Class
Joined
Nov 7, 2013
Messages
76
Re: Trim limit wires...no where to be found

check the wiring coming from the trim pump,I think that's where my were disconnected.

Thats were the Trim sender plugs in...that ones good...I have down and trailer working...the Trim limiter is the one without a home....should tie into the harness somewhere...the wires look like they should be routed under shift lever and up near the fuel pump...but there are no un used wires available....unless your saying all 4 wires go back to the pump?..if so I dont see any spare wires there either.
 

thumpar

Admiral
Joined
Jun 21, 2007
Messages
6,138
Re: Trim limit wires...no where to be found

Which controls do you have? On my old boat there was no provisions for a trim limit switch and they where just zip tyied up.
 

stonyloam

Vice Admiral
Joined
Mar 13, 2009
Messages
5,827
Re: Trim limit wires...no where to be found

Well you could run new wires. The trim switch wire is a purple white wire, should be somewhere back near the transom. There should also be a blue/white wire back there. That is the trailer wire from the control. What you need to do is connect the p/w wire to one
switch wire and splice the other to the b/w wire.
 

84EdH

Chief Petty Officer
Joined
Apr 30, 2011
Messages
575
Re: Trim limit wires...no where to be found

Trim limit wires go to pump. Sender to dash guage. My sender wires tie into shift plate terrminal block then through engine wiring harness to dash guage. Pump should have bullet connectors for limit switch wires.
 

Searay D

Petty Officer 3rd Class
Joined
Nov 7, 2013
Messages
76
Re: Trim limit wires...no where to be found

Trim limit wires go to pump. Sender to dash guage. My sender wires tie into shift plate terrminal block then through engine wiring harness to dash guage. Pump should have bullet connectors for limit switch wires.

Ok...I'm sorry...I misstated i had my terminology backwards....the TRIM LIMIT is plugged into the pump....
1) Trailer function works
2) down works
3) Up does not work

TRIM sender is the one that I can't find where to plug in....the wires look as if the are to be routed up by the shift plate....but there are not any unconnected wires in that area....the kit came with little wires to modify if you boat didn't have the plugs...it changes the wires to terminal type...Talked to a Merc Master he said one is ground and the other goes back to controls....all the wires coming from the sending gauge are black..so thats no help..
84edH...can you share a picture of how yours connects? I don't know which one goes back to controls ..driving me crazy...manual and schematics don't show anything
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
40,581
Re: Trim limit wires...no where to be found

Ok...I'm sorry...I misstated i had my terminology backwards....the TRIM LIMIT is plugged into the pump....
1) Trailer function works
2) down works
3) Up does not work

TRIM sender is the one that I can't find where to plug in....the wires look as if the are to be routed up by the shift plate....but there are not any unconnected wires in that area....the kit came with little wires to modify if you boat didn't have the plugs...it changes the wires to terminal type...Talked to a Merc Master he said one is ground and the other goes back to controls....all the wires coming from the sending gauge are black..so thats no help..
84edH...can you share a picture of how yours connects? I don't know which one goes back to controls ..driving me crazy...manual and schematics don't show anything

Sounds like you have a break in the blue/white wire connection, see wiring attachment
Merc power trim 2012.jpg

As for the gauge look for a Brown/white wire, it goes to the gauge. Here is a 4.3 diagram but it will be the same for you
4_3L elect diag.jpg
 

Searay D

Petty Officer 3rd Class
Joined
Nov 7, 2013
Messages
76
Re: Trim limit wires...no where to be found

Sounds like you have a break in the blue/white wire connection, see wiring attachment
View attachment 219177

As for the gauge look for a Brown/white wire, it goes to the gauge. Here is a 4.3 diagram but it will be the same for you
View attachment 219180

Found the Brown and white wire it attaches to a little blue box that says Mercathod ...maybe a stupid question but what the heck does that do and how do I wire my Trim sender to it?
 

thumpar

Admiral
Joined
Jun 21, 2007
Messages
6,138
Re: Trim limit wires...no where to be found

Mercathode is the corrosion prevention. It has nothing to do with trim.
 

Searay D

Petty Officer 3rd Class
Joined
Nov 7, 2013
Messages
76
Re: Trim limit wires...no where to be found

Mercathode is the corrosion prevention. It has nothing to do with trim.

I see....if the brown and white wire is my gauge why is it wired to the Mercathode? can I just run a junction off the brown and white wire and connect it to my trim sender?
 

thumpar

Admiral
Joined
Jun 21, 2007
Messages
6,138
Re: Trim limit wires...no where to be found

OK I was wrong. The early models did have that wire to the trim position gauge.
 

Searay D

Petty Officer 3rd Class
Joined
Nov 7, 2013
Messages
76
Re: Trim limit wires...no where to be found

OK I was wrong. The early models did have that wire to the trim position gauge.

So should I use that wire?...does it need to stay where it's at?...there must be something i'm missing...there should be a plug or terminal to connect to?
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
40,581
Re: Trim limit wires...no where to be found

Found the Brown and white wire it attaches to a little blue box that says Mercathod ...maybe a stupid question but what the heck does that do and how do I wire my Trim sender to it?

I see....if the brown and white wire is my gauge why is it wired to the Mercathode? can I just run a junction off the brown and white wire and connect it to my trim sender?

Disconnect the brown/white wire from the mercathode and connect it to the trim sender. The mercathode uses an orange and a brown wire (no stripes) which lead to the boats anode. The other two connections go to ground and battery positive

Mercruiser Mercathode Wiring | Performance Product Technologies
 

Searay D

Petty Officer 3rd Class
Joined
Nov 7, 2013
Messages
76
Re: Trim limit wires...no where to be found

Ok..got it I'll try that. Thanks

I think I solved half of the mystery! The brown and white wire went underneath the Mercathode...to a plug which went to the Mercathode black wire.....when I separated the plug there was the Male end for the Sender switch...the remaining wire that went to ground had the female end.... I hooked everything up and my gauge works now....but nothing happens when I push the UP button on the controls...any thoughts?
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,464
Re: Trim limit wires...no where to be found

but nothing happens when I push the UP button on the controls...any thoughts?

Ayuh,..... My guess is the limit switch has been Bad all along,...

Meter it for continuity,....
Or,...
Re-by-pass it inside the hull, 'n it oughta work,....
 

thumpar

Admiral
Joined
Jun 21, 2007
Messages
6,138
Re: Trim limit wires...no where to be found

Here is the Mercathode diagram.

mercathode.PNG
 

Searay D

Petty Officer 3rd Class
Joined
Nov 7, 2013
Messages
76
Re: Trim limit wires...no where to be found

Ayuh,..... My guess is the limit switch has been Bad all along,...

Meter it for continuity,....
Or,...
Re-by-pass it inside the hull, 'n it oughta work,....

I just replaced both switches... brand new... I'll check for continuity
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,464
Re: Trim limit wires...no where to be found

I just replaced both switches... brand new... I'll check for continuity

Ayuh,.... 1 is a limit Switch, the other is a variable resistance Sender,...

The power for the Up circuit runs from yer thumb, through the limit Switch, to the pump solenoids,....

You can chase the power with a test light, or use yer meter,...
 
Top