4.3 mercrusier wires go to??

[Riccinfl]

Just got the boat. What are these wires for!?? Safety issue for sure. I've tried to touch together check for voltage etc.

Any thoughts

 

[Bondo]

Ayuh,..... Welcome Aboard,...... Got a serial number, so we know which 4.3 you've got,..??

 

[nola mike]

Just got the boat. What are these wires for!??

Looks like a TKS model... I'll go with alternator output for orange (if original wiring) and maybe trim limit switch? Need to see where they go...

I've tried to touch together check for voltage etc.

Any thoughts

Yeah, don't do that

 

[Riccinfl]

I can get serial number this evening.. I tried to follow they go down into the main wire loom..

 

[Scott06]

Wonder if it is power to a mercathode that may or may not be present ? I’m assuming it was getting power off the 50 a breaker

You may find some unused wires in the harness

Is that a faded red or orange wire ?

 

[Riccinfl]

Pretty sure orange. I will get better pics this evening and post

 

[Scott06]

mercruiser 4.3 wiring diagram - Google Search

In merc wiring orange goes from alternator to starter lug but the wire shown is too small to be that one.

wonder if someone added a wire for an accessory or stereo etc

 

[Riccinfl]

mercruiser 4.3 wiring diagram - Google Search

In merc wiring orange goes from alternator to starter lug but the wire shown is too small to be that one.

wonder if someone added a wire for an accessory or stereo etc

No as was one owner. I asked him but he can't recall lol

 

[dave8311]

What color is the wire that attaches to the distributor housing?

Maybe they all don't have that wire, don't know.

 

[Riccinfl]

Was a long day sorry I didn’t get out to the boat. I will follow up tomorrow with all information being asked. Thank you so far for y’all help

 

[dubs283]

Photo shows tks on the flame arrestor information decal. If it's original it should have a serial number for the engine and a model number/signifier.

Would be fairly confident the two black appearing wires are ground that have been cut, stripped and twisted together. Definition not oem. Mercury would use harnesses that could be used on different engines of the same vintage that were different models so sometimes you'll see an unused ground in the harness.

The other orange/pink appearing wire may be part of the tks module circuit. It appears too small to be the alternator output line and would be live (12 volt +) if disconnected from the alternator under normal conditions.

Common color 14/16 ga wires for the tks circuit would be red/pur, orange, white and black. Most/all tks equipped engines I've encountered also use Delphi style harness connectors and not ring terminals as depicted in the photo. Possible an early model tks harness used slightly different colored wires and ring terminals? If so possibly someone abated part of the tks circuit?

Best to get the engine s/n and model info to track down the proper wiring diagram and nomenclature for your setup. Extra photos will help greatly as well

 

[Riccinfl]

Here pics. The dang tag on motor is all
Blank from being 07

 

[Riccinfl]

Photo shows tks on the flame arrestor information decal. If it's original it should have a serial number for the engine and a model number/signifier.

Would be fairly confident the two black appearing wires are ground that have been cut, stripped and twisted together. Definition not oem. Mercury would use harnesses that could be used on different engines of the same vintage that were different models so sometimes you'll see an unused ground in the harness.

The other orange/pink appearing wire may be part of the tks module circuit. It appears too small to be the alternator output line and would be live (12 volt +) if disconnected from the alternator under normal conditions.

Common color 14/16 ga wires for the tks circuit would be red/pur, orange, white and black. Most/all tks equipped engines I've encountered also use Delphi style harness connectors and not ring terminals as depicted in the photo. Possible an early model tks harness used slightly different colored wires and ring terminals? If so possibly someone abated part of the tks circuit?

Best to get the engine s/n and model info to track down the proper wiring diagram and nomenclature for your setup. Extra photos will help greatly as well

Photo shows tks on the flame arrestor information decal. If it's original it should have a serial number for the engine and a model number/signifier.

Would be fairly confident the two black appearing wires are ground that have been cut, stripped and twisted together. Definition not oem. Mercury would use harnesses that could be used on different engines of the same vintage that were different models so sometimes you'll see an unused ground in the harness.

The other orange/pink appearing wire may be part of the tks module circuit. It appears too small to be the alternator output line and would be live (12 volt +) if disconnected from the alternator under normal conditions.

Common color 14/16 ga wires for the tks circuit would be red/pur, orange, white and black. Most/all tks equipped engines I've encountered also use Delphi style harness connectors and not ring terminals as depicted in the photo. Possible an early model tks harness used slightly different colored wires and ring terminals? If so possibly someone abated part of the tks circuit?

Best to get the engine s/n and model info to track down the proper wiring diagram and nomenclature for your setup. Extra photos will help greatly as well

I think you nailed it!! I just notice it is a TKS system. But why would they disconnect it?? Should I try to find it and make it working again?? Had no issues starting last year as we only go out when it’s hot out..

Thoughts on what to do

 

[dubs283]

I just notice it is a TKS system. But why would they disconnect it?? Should I try to find it and make it working again??

If the orange/pink wire is indeed part of the tks system it could have been removed because a component of the system failed and instead of repairing it some one abated it. I'm not near any manuals atm but may get to it later today if I have time.

If the tks system is operational you'll note a loud "sucking" noise from the carburetor when the engine is started cold. As the motor warms up the noise will subside. The tks module operates with voltage applied/removed from an engine coolant temperature switch.

Clearer pics indicate the other two wires are black and dark brown? Might be the sender and ground wires for the trim guage. If so, unclear why they would be stripped of bullet connectors and twisted together. Does the trim guage (if equipped) work?

 

[Riccinfl]

If the orange/pink wire is indeed part of the tks system it could have been removed because a component of the system failed and instead of repairing it some one abated it. I'm not near any manuals atm but may get to it later today if I have time.

If the tks system is operational you'll note a loud "sucking" noise from the carburetor when the engine is started cold. As the motor warms up the noise will subside. The tks module operates with voltage applied/removed from an engine coolant temperature switch.

Clearer pics indicate the other two wires are black and dark brown? Might be the sender and ground wires for the trim guage. If so, unclear why they would be stripped of bullet connectors and twisted together. Does the trim guage (if equipped) work?

Yep trim gauge works. I have untwisted them and no difference on anything. Yes black and dark brown.

 

[nola mike]

If the orange/pink wire is indeed part of the tks system it could have been removed because a component of the system failed and instead of repairing it some one abated it. I'm not near any manuals atm but may get to it later today if I have time.

If the tks system is operational you'll note a loud "sucking" noise from the carburetor when the engine is started cold. As the motor warms up the noise will subside. The tks module operates with voltage applied/removed from an engine coolant temperature switch.

Clearer pics indicate the other two wires are black and dark brown? Might be the sender and ground wires for the trim guage. If so, unclear why they would be stripped of bullet connectors and twisted together. Does the trim guage (if equipped) work?

If that wire is red/purple then it goes to tks module. I was thinking the twisted wires were from the trim limit switch and someone jumped them.

 

[Scott06]

I think you nailed it!! I just notice it is a TKS system. But why would they disconnect it?? Should I try to find it and make it working again?? Had no issues starting last year as we only go out when it’s hot out..

Thoughts on what to do

Do you still have a TKS carb or do you have a mercarb with a choke? Possible someone swapped out a TKS for a electric choke carb. I think the execution of the tks carb was not one of Mercs shining moments... wouldn't surprise me if someone disconnected it.

 

[dubs283]

I was thinking the twisted wires were from the trim limit switch and someone jumped them.

Trim limit switch/wiring is not associated with the engine wiring harness.

Wire colors for the limit switch are purple and blue and are part of the trim pump wiring harness

I'm guessing it's possible someone installed separate wiring for the trim guage if the brown and black wires pictures are indeed for the trim guage

At this point it's in OP's best interest to verify any power/ground on the suspect wires. If all are not powered or simply ground and all systems are functioning normally the wires may be superfluous, i.e. part of a harness that is used on multiple engine models

 

[nola mike]

Trim limit switch/wiring is not associated with the engine wiring harness.

Wire colors for the limit switch are purple and blue and are part of the trim pump wiring harness

I'm guessing it's possible someone installed separate wiring for the trim guage if the brown and black wires pictures are indeed for the trim guage

At this point it's in OP's best interest to verify any power/ground on the suspect wires. If all are not powered or simply ground and all systems are functioning normally the wires may be superfluous, i.e. part of a harness that is used on multiple engine models

Yeah, couldn't remember limit switch colors off hand. Couldn't figure why they'd be twisted otherwise though unless they're grounds. Feel good about that other wire being from the TKS mod though.

 

[Riccinfl]

If that wire is red/purple then it goes to tks module. I was thinking the twisted wires were from the trim limit switch and someone jumped them.

Ok tks is working. I guess it really don’t matter but I just want to know why they are just hanging out there