The Mariah Owners Club - Unknown Wire

The Mariah Owners Club (http://www.mariahownersclub.com/forum/)

- Mercury MerCruiser (http://www.mariahownersclub.com/forum/mercury-mercruiser/)

- - Unknown Wire (http://www.mariahownersclub.com/forum/mercury-mercruiser/2753-unknown-wire.html)

After tearing everything apart and putting it all back together this past weekend - I now have a wire that I have no idea where it goes. I'm just happy I wasn't left with any nuts, screws, or washers.

It does not go to the engine hatch lift and everything runs just fine.

Below is a pic - any suggestions are appreciated.

Re: Unknown Wire

That looks like a engine warning alarm system wire. If it's got a blue line on it, I believe that's what it is. I'll check and get back to you...

Re: Unknown Wire

I believe our big blocks have dual oil and water senders, one set for the warning system and the other for the dash gauges.

If it's all Tan, I believe it goes to the water temp sender for the dash gauge.

Re: Unknown Wire

Thanks.

Where does it connect to in the engine compartment?

Re: Unknown Wire

Quote:

Originally Posted by 2000Z272 (Post 15306)

Thanks.

Where does it connect to in the engine compartment?

Hi 2000Z272,

Looking down from the front of the motor:

http://i66.photobucket.com/albums/h2...mpsenders2.jpg

Just make sure it's really the Temp Gauge wire before you connect it up.

WetWilly

Re: Unknown Wire

Thanks for taking the time to put that together - hopefully I will have time tonight to check it out. I'll let you know.

Re: Unknown Wire

Below is a pic of the engine - I only have the one sensor on the left. I'm thinking that it may be the blower wire for my quicksilver keyless ignition. But, I don't know where it hooks up to the blower at. The search continues.

Re: Unknown Wire

The 2000 wiring diagram shows the tan wire as the captain's call exhaust. Is your boat fitted with the selectable exhaust? If not, then there is nothing to connect it to. :wink_thumbup:

Re: Unknown Wire

Unfortunately, no thru-hull exhaust.

Thanks.

Re: Unknown Wire

Hi 2000Z272,

Sorry, didn't know you had the MPI model with keyless start. You may be right, I remember reading somewhere when activating the keyless ignition, the blower would turn on for about 4 minutes before the motor starts. The spade connector on the end of the wire does not look like the ones Mercruiser uses, perhaps the previous owner installed it? You could try locating the Blower wiring and see if you can find a open splice somewhere.

Per the Mercruiser manual, depending on the model/make/year of your 7.4 MPI, there are two other TAN wires for the engine wiring system, although I doubt it's one of these two, here goes - On Page 4F-22 of the 7.4 electrical system manual, the diagram shows a TAN wire going from the ECM to the Intake Air temp Sensor and the other Tan wire going from the ECM to the Harness connector to the Starting/Charging harness.

If it were me, I would try to follow the wire back to it's source, I assume up at the dash, to determine which circuit it goes to. If you end up tracing it back, let us know where it comes from.

WetWilly