hour meter

[Baysider]

My hour meter on my 1990 C34 stopped working recently so I pulled the panel today and found a loose orange wire with a tape label saying Tach.  Before that it says what looks like an S and something that's illegible.  It looks like it could have broken at the insulation, or perhaps was cut.  I was thinking it's possibly what should power the meter. Does anyone know offhand which connector on the back of the Tach gets the wire which powers to hour meter?  I'd like to include some pics I took but am unable to figure out how to do so.

The tach has connections that say send, GND, ign and Lt+ (the latter which I know powers the lamps).

Thanks!

[KWKloeber]

@Bay

First, it would help if you would put your engine info in your auto signature.  Help US to help YOU.

Second - are you saying that only the hour meter isn't advancing but the Tach IS WORKING?  That can happen -- but not if the Tach sender wire is off.  One signal drives both the Tach and HM.

ORANGE was always the charge cable back from the panel.  But I have also seen the Tach signal wire being orange, gray, or brown/tan.  It belongs on the SEND post -- is there an "empty" ring terminal there (if the wire was broken off of it)?

About the photos -- There's an oddity in the "better, improved" forum software.  If you want to add a photo, you need to click to "Preview" your message -- then the bar appears at the bottom to drag in an image file or click to browse it.

By the way, the wiring diagram is in your engine manual (which if you don't have one you can download from the Wiki site) -- it shows where the Alternator Tach signal wire connects to the Tachometer.
https://c34.org/wiki/index.php?title=Manuals

[Noah]

@Bay
About the photos -- There's an oddity in the "better, improved" forum software.  If you want to add a photo, you need to click to "Preview" your message -- then the bar appears at the bottom to drag in an image file or click to browse it.

Ken— I have not found this issue posting photos. I never have had to "preview" using the new software. Hmmm?

[Baysider]

Thanks Ken, I have updated my profile as you suggested.  I will try to attach a few photos using the preview page.  Among them will be the rear of the tach.  I looked at the wiring diagram in the manual and, assuming it represents a rear view, the ignition and send are juxtaposed relative to my unit.  So it's helpful that you've said to attach to SEND.  Now the troubling part. There is a somewhat orange/brown wire on the send post and no additional ring terminal.  Its absence had me wondering, but with the info you've laid out I'm wondering if the loose orange wire was never connected (even though it's labelled tach) and the hour meter mechanism is actually stuck.  Next time I'm at the boat I'll check for power at the send post but I'm not clear on how to deal with a stuck mechanism.

By the way, the tach works but not the hour meter

[Baysider]

So I should be able to check for power to the hour meter with the ignition switch in the on position and test leads on the send and ground posts?  Just wondering where the tach itself gets its input regarding engine speed.

[scgunner]

Baysider,

The odometer on my tachometer failed several years ago, it wasn't the wiring it was the gauge itself. I installed a separate odometer at the nav station which has worked out very well. It's handy when making log entries and it's out of the weather. Like the odometer on a car it's important so you can establish a baseline for regular maintenance on the motor.

[Baysider]

Thanks Kevin.  I assume you took power off of the fuel pump.  If so, which terminal feeds the meter?

[KWKloeber]

@Bay

You have a failed hourmeter.  The tach/HM is not serviceable so the HM portion is toast.

Both are driven by the SEND wire from the Alternator and so long as the Tach works you have 12v power, Ground, and signal to the Tach.  Replace the Tach/HM or install a separate HM at the Nav or in the engine space.  Taking a voltage reading on the SEND post will tell you nothing about the HM.

The orange wire is most assuredly the charge wire back from the Ammeter before the PO replaced it with the Voltmeter.  Why is it mislabeled? who knows.
I have a theory why but its just a theory so doesn't matter now.
What does it say before "Tach"? Possibly "+" or "Ign"?

-Ken

PS:
I have comments about your "newly acquired panel" that I'll post separately.

[Baysider]

Thank you Ken.  It makes sense that both work off of the same wire.  I will replace the broken hour meter.

As far as the wiring goes the "open" orange wire is part of the upgrade bundle that was installed at some point in the past.  It looks like perhaps an 18 gauge wire. Was such a thin wire used running to the ammeter? The tape has what looks like an S and something that's illegible before it has tach written on it.

[Jon W]

Baysider, my hour meter failed a few years ago as well. Like Kevin, I installed a separate hour meter at the Nav Station (upper right corner of photo). I added a label underneath it with the hours where the original stopped. I add the two together to get total engine hours.

[Baysider]

Thanks Jon.

[KWKloeber]

....the "open" orange wire is part of the upgrade bundle that was installed at some point in the past.  It looks like perhaps an 18 gauge wire. Was such a thin wire used running to the ammeter? The tape has what looks like an S and something that's illegible before it has tach written on it.

@Bay

Yes, I noticed the CD upgrade wires.  But what has me baffled is that the CD hunl of wire does not include orange:

• Black - Ground
• White - Glow Plugs
• Yellow w/red stripe - Starter
• Red - Battery +
• Purple - Alternator excite
• Blue w/black stripe - Oil Pressure switch
• Tan - Temperature sender
• Gray - Tachometer
• Tan w/black stripe - Water temperature switch

The ORG charge wire from the Ammeter back to the Starter Solenoid was 10 gauge (same as the RED feed to the panel and BLK Negative.)  Is that ORG wire within the "bundle" of the new harness wires? 
There was no light ORG gauge wire used in the original or CD's "upgrade".  The lightest wire in the original harness was the 16 gauge YEL/RED Stripe "S wire" to the Starter Solenoid.

What's left inside the engine compartment -- i.e., where does that ORG wire end up? I repurposed my ORG charge wire for an oil-pressure gauge at the panel.


Something that irks me (as do many things about CD!) is they are servicing Catalina owners, and their hunk 'o wire (so-called harness upgrade) does not include the fuel pump feed wire. 

[Jim Hardesty]

I added a label underneath it with the hours where the original stopped. I add the two together to get total engine hours.

Good Idea. Would also note in the maintenance log. I'm thinking if it were necessary to add a Hobbs gage (hour meter) I would add 2, the extra one would be resettable and I would zero it at fuel fills.  They aren't very expensive or very large.  It's possible that they make one with a dual function.
Jim

[Stu Jackson]

I added a label underneath it with the hours where the original stopped. I add the two together to get total engine hours.

Good Idea. Would also note in the maintenance log. I'm thinking if it were necessary to add a Hobbs gage (hour meter) I would add 2, the extra one would be resettable and I would zero it at fuel fills.  They aren't very expensive or very large.  It's possible that they make one with a dual function.
Jim

That's one way.   I just keep a log.  An easier way is to just make a note of when you fill and add 20 hours and then go buy 10 gallons (for an M25 series).

[scgunner]

Baysider,

That was about 800 hours ago so my memory of the details is a bit foggy. But the hour meter came with instructions and the install was not difficult. As I recall I hooked it up to the ignition which works because the fuel pump is also hooked up to it. As you'll note when the ignition is turned on the fuel pump also clicks so even though the hour meter is running with the motor off it would be unusual to leave the ignition on for more than a few minutes.