C180: What is the OEM wire to the battery....

[Carboncow]

OK, so no photo...but I don't think it would really help. There are 4 OEM wires going to the hot leg of the battery on my 2007 C180, 5 if you include stater. They are as follows, sans one:

1. heavy 4-6 gauge to switch/starter
2. Red 12-14 gauge going to stereo (fused)
3. Red 12-14 gauge going to house/dash stuff (fused)
4. Black with red stripe 12-14 gauge (fused) that is the "always on" for the bilge switch
5. Orange >> WTF?

What is that orange wire (fused) and approx. 12-14 gauge running into the loom with everything else. I feel I've isolated everything on the boat (twice) and can find nothing it services. Since it's there with the stereo I'm thinking it's the "always on" to keep the stereo memory intact but that doesn't appear to be in. My Clarion M303 either keeps memory on it's own or it's getting "always 12v" from somewhere else.

I hooked up a 2nd 12v deep cycle to run the stereo and LED stern lights with a Battery Doctor isolator/combiner. I ruled that everything else goes on my starting battery...

...but just curious what that rouge orange wire services!

 

[Carboncow]

Bump and a photos...anyone? Bueller?

 

[Eclipse1701d]

Possibly runs to your bilge pump to kick in when battery is off?

 

[RowdyRod]

Hmmmm.... not sure if this will help... but my original switch was wired up as follows with 6 wires....

Live side of switch
1. Red 6 GA wire from battery positive terminal
2. Orange wire to stereo (memory backup) with 1A fuse
3. Brown/Red wire to bilge pump with 3A fuse

Switched side of switch (does that make sense?)
4. Red 6 GA wire to Solenoid
5. Red wire to main MPEM Block with 20A fuse
6. Red wire to main MPEM Block with 20A fuse

I'm not sure why they had two wires going from the main switch to the MPEM controller, maybe its cheaper than running a larger gauge and bigger fuse.

I suspect your mystery orange wire is connected on the live side of the switch, i.e. it's always on, and it's used for the clock in the stereo and memory backup. I removed mine as I don't like the drain on the battery when in storage for a long time.... I like to know that when the main battery switch is off... it's really off!

 

[Carboncow]

Hmmmm.... not sure if this will help... but my original switch was wired up as follows with 6 wires....

Live side of switch
1. Red 6 GA wire from battery positive terminal
2. Orange wire to stereo (memory backup) with 1A fuse
3. Brown/Red wire to bilge pump with 3A fuse

Switched side of switch (does that make sense?)
4. Red 6 GA wire to Solenoid
5. Red wire to main MPEM Block with 20A fuse
6. Red wire to main MPEM Block with 20A fuse

I'm not sure why they had two wires going from the main switch to the MPEM controller, maybe its cheaper than running a larger gauge and bigger fuse.

I suspect your mystery orange wire is connected on the live side of the switch, i.e. it's always on, and it's used for the clock in the stereo and memory backup. I removed mine as I don't like the drain on the battery when in storage for a long time.... I like to know that when the main battery switch is off... it's really off!

Thanks. Great info. I actually assumed that orange was also the "always on" for the stereo but I have a new Clarion M303 and even if I take that wire off it retains my clock/radio stations!

So since we share the opinion I'm going to assume that after 1000 years of stereos they are starting to put memory batteries in them!??! I know the schematic for the stereo still says to hook it up. I'm going to crack the manual on the stereo again. There was no reason it should retain power.

 

[Carboncow]

OK. M303 manual still has a yellow memory wire (interestingly 15amp fuse required) and makes no mention of battery backup. So I'm really scratching my head how it was maintaining power. I'll do some more investigating today and report back. If the weather holds I hope to seal trial today after a few last minute tweaks.

 

[RowdyRod]

The plot thickens Yep even after a 1000 years they are still using volatile memory... dumb.

My crappy GME unit is the same, but I only use an iPod directly connected to it so don't have to worry about the radio station memory.

 

[Carboncow]

The plot thickens Yep even after a 1000 years they are still using volatile memory... dumb.

My crappy GME unit is the same, but I only use an iPod directly connected to it so don't have to worry about the radio station memory.

I will prob never use the radio either...but it's the principle to have it working for me since it's all new! Yep...I have an iPad that will go on the help for navigation and to run the music via bluetooth attached with a RAM mount. That should be finished today.

 

[Carboncow]

Hmmmm.... not sure if this will help... but my original switch was wired up as follows with 6 wires....

Live side of switch
1. Red 6 GA wire from battery positive terminal
2. Orange wire to stereo (memory backup) with 1A fuse
3. Brown/Red wire to bilge pump with 3A fuse

Switched side of switch (does that make sense?)
4. Red 6 GA wire to Solenoid
5. Red wire to main MPEM Block with 20A fuse
6. Red wire to main MPEM Block with 20A fuse

I'm not sure why they had two wires going from the main switch to the MPEM controller, maybe its cheaper than running a larger gauge and bigger fuse.

I suspect your mystery orange wire is connected on the live side of the switch, i.e. it's always on, and it's used for the clock in the stereo and memory backup. I removed mine as I don't like the drain on the battery when in storage for a long time.... I like to know that when the main battery switch is off... it's really off!

Rowdy,

I'm re-reading your post and I think you may be mistaken although you Speedster may be totally different. Two reds on mind which are the same gauge are separate and one is the House (gauge and I'm assuming MPEM) and the other is the stereo hot.

Does you stereo come right off the house wiring which I'll assume in the MPEM? Have you tried to isolate any of those to see if your stereo goes offline?

 

[RowdyRod]

Sorry Carbobcow, I missed this post. The stereo on mine comes from the house wiring which is the MPEM fuse block. There is a fuse in there for the stereo. I haven't tried so see if they are isolated in the MPEM, I will check that out when I get a chance.