Console buzzer alarm - electrical problem?

[Breakin Away]

I finally got the old oil pressure switch off! A 1-1/16" crowsfoot tool was able to get in at the correct angle to grab the flat spots. I threaded on the new switch, but ran out of time before I was able to connect it. I'm not going to use the AutoZone pigtail because there are two large gauge wires crimped onto one of the connectors, and I'm not comfortable butting two larger gauge wires down onto a much smaller gauge single wire on the pigtail. Also, when I tested the connector on the new switch, it went on so tight I nearly destroyed the switch getting it off. And that's with it right in front of me - someday I may need to take it off and it's going to be in a very inaccessible part of the motor, so not gonna go there.  I'm going to fix what's broke, and leave what's working.

I borrowed a radiator pressure tester to track down a coolant leak this weekend. After fixing that (hopefully just a loose hose clamp), I'll heat up the oil, change it and the filter, put the antifreeze in, and then I'm done with the motor for the winter. I'll finish pulling off all the canvas and put the cover on.

[KWKloeber]

Which swtich tab was broken off -- with the single crimp or the double crimped wire?

kk

I finally got the old oil pressure switch off! A 1-1/16" crowsfoot tool was able to get in at the correct angle to grab the flat spots. I threaded on the new switch, but ran out of time before I was able to connect it. I'm not going to use the AutoZone pigtail because there are two large gauge wires crimped onto one of the connectors, and I'm not comfortable butting two larger gauge wires down onto a much smaller gauge single wire on the pigtail. Also, when I tested the connector on the new switch, it went on so tight I nearly destroyed the switch getting it off. And that's with it right in front of me - someday I may need to take it off and it's going to be in a very inaccessible part of the motor, so not gonna go there.  I'm going to fix what's broke, and leave what's working.

I borrowed a radiator pressure tester to track down a coolant leak this weekend. After fixing that (hopefully just a loose hose clamp), I'll heat up the oil, change it and the filter, put the antifreeze in, and then I'm done with the motor for the winter. I'll finish pulling off all the canvas and put the cover on.

[Breakin Away]

Which swtich tab was broken off -- with the single crimp or the double crimped wire?

kk

Actually I do not remember, since it has been so long since I pulled the other one off to shunt them together for testing. They're still shunted together until I go down to finish the job tomorrow.

[KWKloeber]

My guess (if I had to) is the double-crimped is what broke off.  That's what I've seen on others. 

Understand from what I explained previously, that Wb uses SAE, not marine wire, and stiff wire, not Type III flexible, thin-strand wire.  Using the wrong wire is WHY the tabs break, and double crimping TWO bad wires onto one tab exponentially raises the chance that the tab will break.  You've eliminated the symptom but not the cause --- it will break off again.  Just a matter of time.

The only current going thru that switch is the lift pump -- I measured mine years ago, and it was under 1 amp -- don't remember exactly, but let's say 1 amp.  16 awg is even overkill for that amperage, and Wb runs 10 awg plus 14 awg into one terminal -- not only isn't that a good idea, it's just another failure point and isn't necessary.  The double feed to the switch branches off the switch and is the feed to excite the alt field to get it kicked in and charging.  That's low current also -- a 14 gauge would be overkill. 

The proper way to do it is to NOT crimp two wires into that terminal PLUS, both wires to the switch should be light gauge, AND fine stranded (Type III)  so as to NOT transfer ANY harness movement to the switch tabs (they flex and break off)  (which is alternately what the boot does.)  I understand concern about the boot being tight (I am ordering one and a sw to experiment) but putting it all back as it was, is just ignoring the underlying problem.  I'm not sure if that alt has an "excite" terminal post -- if it does, the proper way would be to run the feed to the alt post first, then to the switch (using two ring terminals on the alt post.)  Using marine Type IIi not SAE, wire of course.

Alternately -- on the crappy Wb wires, butt crimp short (6"?) 16 awg type III wire to the switch terminals.  If you leave the double crimp at that location, use a step down butt, Wb's two wires in one side, and a 16 awg to the switch out the other side.

-kk

[Breakin Away]

OK, it has been a very productive couple of days. Three problems solved: coolant leak, oil pressure switch, and tachometer.

First, I borrowed a radiator cap/radiator pressure tester from AutoZone. It does not have nearly as many attachments as other stores', but the one they had fit perfectly. (There are reviews on the AutoZone website claiming that this device only tests radiator caps, but those reviews are wrong.) First I used the double-ended adapter to test the cap, then I hooked it up the the motor and pressured up to 14 psi. In what is a clear violation of Murphy's law, the coolant leaked out the hose fitting right at the coolant cap, so it was easily tightened and held pressure all night. I had been misled on the location of this leak because of the long path the leaked coolant took back to the outside of the heat exchanger, then dropping off the HX onto the floor, and eventually forward into the bilge. I thought it was from the hot water tank or from the HX, but it turned out to be from the easiest place to fix.

With that fixed, I wired up the new oil pressure switch with the existing wires. Those wires are very stiff and especially resistant to twisting into the needed orientation to go onto the tabs (especially with SuperLube on my hands!). But eliminating the double-crimp by rewiring to the alternator looks like it will require either removing a bunch of hoses or the alternator itself. That's too much to take on with a short timeline to winter. It's on the list for spring, but I needed to focus on winter preparations, so the existing wires went back on as-is.

Once I had my cooling bucket all set up through the emergency hatch (see pic below), the motor fired up right away and the pressure alarm stopped immediately. Switch fixed! Motor ran for 20 minutes to heat up the oil. At this point I noticed that my on again/off again tachometer problem was on again. Tach initially revved up when initially starting, but immediately went to zero. Since this is an intermittent problem, I stopped and started the motor a few times to see if it persisted. Same thing every time - no tach after initial startup.

Last weekend I had tried to pump out the oil twice, with a drill pump kit and then a hand pump, and neither one would draw the oil at anything close to an acceptable rate. So I sprung for the really nice Jabsco Quick Change pump with the bronze impeller pump (not the cheaper and more problematic diaphragm pump). While expensive, it does the job great and minimizes your time in cramped quarters handling hot oil. Just pump it out into the permanently mounted pail, then reverse the pump direction to pump it into a disposal bottle. So the oil, filter, and ATF were both changed easily.

I was going to defer fixing the tachometer until spring, but decided to see if there might be a quick fix. The tach lead on the back of the alternator was right at the top - easily accessible, with no rubber boot on it. It also had original paint on the nut and threads, which is often not a good sign. So I took off the nut (along with its paint), cleaned up the loop terminal and everything else, and hooked it up again. While doing this, I noticed some coolant residue from the prior coolant leak, and it occurred to me that this residual liquid may have shorted the tach lead to ground. This could also explain the intermittent nature of the tach problem, since tach would seem to work fine after several days of drying, but could short out with fresh coolant splashing onto the mount. Just a hypothesis - I may never know for sure unless something happens again.

So with this fix done, I fired up the motor to prepare for winterization. Tach worked perfectly. Once again, I shut down and restarted a couple of times, and tach worked each time. So with three problems fixed in one weekend, I decided it's time to winterize. I drained residual water from the muffler and the raw water strainer, the filled the strainer with antifreeze and started up. While running I continued to pour 3 gallons of antifreeze through the system via the strainer, than noted that the exhaust was clearly expelling purple juice. I shut down with a brief surge of throttle (which a mechanic friend told me to do because the excess fuel fogs the cylinders), taped shut the air intake and exhaust, and called it a season. I can't wait to blow out the antifreeze in spring!

Now to strip the rest of the canvas and put on the cover (plus raking and mowing around the house). It never ends...

[Noah]

Once again I salute all you cold region sailors!

[KWKloeber]

Nice isn't it when something like a leak is BOTH QUICKLY found and EASILY fixed!   

Cool that the tach issue also seems to be resolved - - that's why I really wanted to separate the two steps -- if it was due to the excite wire, you might never have found the real cause.

Note on the alt / oil sw / wires / terminals:


A couple different alts were used -- with different excite connections.  The XPB harness I replaced did have the threaded post alternator, but some have a plug on the alt (with a double-crimp butt connector), and some have a single wire to the regulator (also with a double crimp butt.) 

If you have the threaded post style -- it ALSO will have a double crimp ring terminal, similar to at the oil switch (it's just a bad dream what Wb did) so you'll run into the same issue.  So in your case, the way you describe, you'll have to cut/crimp on ring terminals for the two wires to the alt excite post, and run a new wire back to the switch. 

If you have the plug or single-wire on the regulator type alt excite, then you'd have to cut one of the two wires going to the excite, and use a step-down butt connector to run your new wire back to the oil switch.

For any of them, you'd as well need to cut and butt crimp together the double-crimped terminal wires at the oil switch -- but with access to the area very limited on your boat, you may not be able to do that or have enough "excess" harness length to do all of those.   Wb was NOT generous!!
(confusing? -- I can mark up a schematic what to do if you need me to.)

Here's a simpler way:

Make up two male quick disconnect by female quick disconnect jumpers using 16 awg Type III wire (see length below.)
Connect the jumpers to the harness oil sw terminals, a little bit of dielectric wouldn't hurt, and adhesive heat shrink  (mil spec) over your connections.  Tie the existing oil switch wires down where you can, to prevent movement (maybe to the oil switch/hose bracket?) 

Voila', you have flexible wires to the switch, w/o messing with the alternator.
The length of your jumpers would be set by where/how your harness wires can be tied down.

Of course this does a waltz around the issue that additionally, wiring to the alternator (as well as anywhere that there could be harness movement / vibration) should also be Type III marine, not SAE wire (this was the whole reason behind the owner wanting the new harness fabricated!!)

-kk

OK, it has been a very productive couple of days. Three problems solved: coolant leak, oil pressure switch, and tachometer.

the coolant leaked out the hose fitting right at the coolant cap, so it was easily tightened and held pressure all night. I had been misled on the location of this leak because of the long path the leaked coolant took back to the outside of the heat exchanger, then dropping off the HX onto the floor, and eventually forward into the bilge. I thought it was from the hot water tank or from the HX, but it turned out to be from the easiest place to fix.

With that fixed, I wired up the new oil pressure switch with the existing wires. Those wires are very stiff and especially resistant to twisting into the needed orientation to go onto the tabs (especially with SuperLube on my hands!). But eliminating the double-crimp by rewiring to the alternator looks like it will require either removing a bunch of hoses or the alternator itself. That's too much to take on with a short timeline to winter. It's on the list for spring, but I needed to focus on winter preparations, so the existing wires went back on as-is.

The tach lead on the back of the alternator was right at the top - easily accessible, with no rubber boot on it. It also had original paint on the nut and threads, which is often not a good sign. So I took off the nut (along with its paint), cleaned up the loop terminal and everything else, and hooked it up again. While doing this, I noticed some coolant residue from the prior coolant leak, and it occurred to me that this residual liquid may have shorted the tach lead to ground. This could also explain the intermittent nature of the tach problem, since tach would seem to work fine after several days of drying, but could short out with fresh coolant splashing onto the mount. Just a hypothesis - I may never know for sure unless something happens again.

So with this fix done, I fired up the motor to prepare for winterization. Tach worked perfectly. Once again, I shut down and restarted a couple of times, and tach worked each time.