1987 170 Wiring

[gran398]

Just wondering...where did you decide to put the bilge switch?...tx.

[seabob4]

At one end or another, I would imagine...

If I may chime in here, no offense to anyone.  IF the bilge pump has to be kicked on in an emergency, well, guess what?  The float has already done that for you!  One item on everyone's checklist, pre-launch, should be to check the operation of the float switch. Yeah, no fun, have to lay on your belly, reach down into nasty places, that sort of thing.  But if the float doesn't kick on the pump automatically, then it's time to find out why...and if you still want to go boating, it's time to be aware of any water accumulating in your bilge...at all times!

If you hole your hull?  Forget about it.  Unless you have a couple of 2000 GPH pumps to at least slow it down, bilge pumps won't do a damn thing to prevent the inevitable.

A bilge pump is intended to remove water that has entered the boat due to excess rainwater, shipping water over the gunnels, that sort of thing.  A properly operating float switch, wired properly (constant hot, protected by a 10A fuse or breaker), will take care of these issues.

Ensure your float is always in good condition and that it does the job it is supposed to...turn on your pump when water enters the bilge!!  Ensure your float is wired constant hot, so that even when your batt switch is off, it will still turn on the pump when unwanted water enters the bilge.

Sorry for the rant, but emergency situations?  That's what your float, among other things, is there to do.  In emergency situations, your mind should be on other things, like saving your passengers, alerting authorities, assessing the emergency, that sort of thing.

Sorry for the rant...

[wingtime]

I put the bilge switch on the far right side.  I'll take some better pics soon.  I love the rockers...  easy.. feel great just tap the top of them and they are one.  Much better than toggle switches.

Good point on the bilge safety rant Bob!  One of my habits is to hit the bilge switch for a moment when I get the boat up on plane.  That way I will know if water is finding it's way in before the float switch catches it and most of the water runs to stern at that time too.  To be honest I'm not sure if the 170 has a float switch or not.  I didn't notice one so that is on my list to see if it is there and if it works.  If not that will be on the top of the list to install.

[gran398]

That wasn't a rant. Safety first.

[wingtime]

That wasn't a rant. Safety first.

Well yeah rant isn't the right word..  soap box maybe?

[RickK]

My 170 never had a bilge pump, let alone a switch.

[seabob4]

My 170 never had a bilge pump, let alone a switch.

I hope you installed one...

Interesting read MANY years ago in, of all things, the Worst catalog (yes, an actual paper catalog!) on small boats and bilge pumps.  Small boats usuallly have lower gunnels, hence they can ship water over the sides easier, they also have small bilges that can fill much quicker than larger boats...so they recommended fitting the largest bilge pump you could in smaller boats.  I like that idea.

Yet every small boat I see has this dinky little 500 GPH pump in there with a 3/4" discharge.  I guess it came down to cost in the boat...

[wingtime]

The 170 actually has a good sized pump in there, 1200 or 1500 I think. But now that you mention it the hose and thru hull fitting look pretty small.  Also there is no access to get to the back side of the thru hull fitting. So I guess a pie plate is in order.

[RickK]

I will take the plunge and put one in during this rebuild.  There was no exhaust holes in the sides for a pump either.  I think it was because they had the upper deck sealing off the bilge and no water could get down there unless you had a breach in the hull.  I will have to run a hose over to and under the liner to exhaust.

[wingtime]

Okay I was wrong its a 750 gpm pump with no float switch. There is a bunch of wires down there so maybe at one time there was a float switch.

I found a single tan wire under the console that looks like it is connected to the temp guage. I also found a coiled up tan wire under the engine cowl that isn't connected to anything . It does not appear to be part of the engine harness. The temperature guage is not working either. I suppose I should ground the end of that wire and see if the guage pegs. My question is shouldn't  the factory engine harness already have a tan temperature wire already?

[seabob4]

Bruce, if my memory serves me right, solid tan is engine temp on OMCs...

Follow where that tan wire is terminated on the powerhead.  Should end up at a sensor looking thingie...

[seabob4]

Bruce, in regards to a constant hot lead for the float switch, you should look for a brown w/red stripe wire.  The smaller boats, it went straight to the batt.  The bigger boats, like your Explorer, went to the little black box in the transom...you know the box...

[wingtime]

Bob the tan wire is coiled up in a big loop  on the port side of the power head and is not connected anything. Definitely not part of the factory omc harness. There are two thermastat senders one on each head that have tan wires that are part of the power head wiring.

I didn't get to mess with the temp guage yet since I spent three hours yes three putting in a 4" pie plate!  I used a 4" hole saw to cut an access hole in the aft stbd liner so I could access the through hull fitting for the bilge pump. The inside of the liner had a 3/4" unobtainium plywood backing plate that was hard a a rock!

[seabob4]

Almost sounds like the old "Whalerboard"...

[wingtime]

Before leaving for work this morning I grounded the tan wire in question.  Yup the gauge pegged full scale.  I did confirm that the tan wire is run separately by itself and is NOT part of the factory OMC harness.  I do not want to cut into the engine harness to attach the wire.  I'm certain there is a proper wire already in the engine harness.  I'll just have to search for it on the console end of the harness.  I also determined my trim gauge is working by moving the sender lever by hand.  It just seems to be gummed up and sticking.