Both tachs stopped working

bluedawg

New member
Hello, I just bought Blue Dawg, a 2007 22' cruiser with twin Honda 40's. I am having some electrical issues that I am working through and one of them that the previous owner had not fixed is neither tachometer is working. He stated that they both quit working so he replaced them and the new ones didn't work either. I assume there is a blown fuse somewhere or possibly a rectifier issue? Any help on what and where to check first would be greatly appreciated.
 
make sure on the throttle control box that all plugs are attached. Often there are three wires going from that to each tach. Usually there is a short wiring loom that has a connector that goes forward from each controller.
 
And, as strange as it may sound, make sure your battery cables are tightly secured to the battery lugs. I had a tach problem too once and this ended up being the solution. I now use two hex nuts, one as a lock nut on top of the other, rather than wing nuts.
 
for wiring colors and harness connector position. might be a broken wire, loose or poor connection. Purchase electrical contact cleaner to clean
 
MOOSE":frbbb6p5 said:
And, as strange as it may sound, make sure your battery cables are tightly secured to the battery lugs. I had a tach problem too once and this ended up being the solution. I now use two hex nuts, one as a lock nut on top of the other, rather than wing nuts.


Also make sure all wires are connected at the batt., check fuses under each engine cowl, & inline near the control box (shift -throttle).
:wink:
 
Well last night I took off all battery cables and cleaned them well, I also had the battery tested and it checked out (brand new Interstate). Now comes the really screwy part, I have been getting low voltage alarms on my Garmin but when I put a tester on the battery it shows 12.2 volts so I started the starboard motor and ran the rpms ups a bit and put the meter back on the house battery and it only went up to about 12.8 volts. when I did the same thing with the port motor and put my meter on its battery it went to ~13.3 volts.

Wait it gets better, I hooked everything back up and then this morning went to look everything back over and checked the battery still 12.2 (I did have the house switch off all night) but the Garmin will not turn on, you can see that the buttons will barely light up but nothing turns on. I also noticed that when trying to turn on the Garmin that the tachs were lighting up as well. I am soooooo lost. I made sure that all cables were clean and snug and none look or feel in bad shape.
:(
 
you might look at engine side battery cables. Disconnect at battery or switch for no voltage with your DVM, then remove, clean, reinstall and tighten
 
something is amiss

Fully charged batteries should measure at 12.6 volts or above at rest. When the engine is running, this measurement should be 13.7 to 14.7 volts.

Loose or poor cables? easy to check. remove and clean

Battery needs load testing.

Alternator and regulator needs checking
 
One other thing you mite consider is the size of the wire going from the battery to the buss by the helm. I had this problem on my 22 until I ran larger power and ground wires to the buss. Too many things for the size of the wire. We tend to add more toys to the boats over time.
 
Okay guys, first thank you for the ideas and trying to help. I gave everything another look over last night and the only wiring I found that was in less than perfect condition was the 50 AMP thermal circuit breaker. I had initially looked past this because the terminals were covered by tiny rubber caps. Once I removed those I could see that they were extremely corroded. When I tried to remove the nuts they both broke. I think NAPA has a replacement so I will pick it up today and install it and also freshen up the lengths of wire going to it. Again thanks for the help. I will report back with the results.
 
Check the battery cables themselves with the multi-meter for resistance.

If water, particularly salt water, is allowed to get into the space inside the insulation with the copper conductors, corrosion can set in and limit or destroy their conductivity.

This is why marine cables are tinned with a tin coating to help protect the copper underneath from corrosion, but add enough salt, particularly back near the splash well/motor well, and all bets are off. :lol:

Good Luck!

Joe. :teeth :thup
 
bluedawg":2hppqf0k said:
Okay guys, first thank you for the ideas and trying to help. I gave everything another look over last night and the only wiring I found that was in less than perfect condition was the 50 AMP thermal circuit breaker. I had initially looked past this because the terminals were covered by tiny rubber caps. Once I removed those I could see that they were extremely corroded. When I tried to remove the nuts they both broke. I think NAPA has a replacement so I will pick it up today and install it and also freshen up the lengths of wire going to it. Again thanks for the help. I will report back with the results.
bluedawg,

If the connectors on that 50 A breaker are that corroded, it is likely that you have bad connections at other locations also. And, it is very likely the wiring is shot in some stretches, from your description. Untinned wiring (aka bare copper under the insulation), over time, will corrode, forming a dark material. The wiring can look OK until you peel back an inch or so of insulation. This corrosion can run the entire length of a wiring run.

How old is the wiring? Did the previous owner mention whether he replaced major sections?

Those two tachs might be dead if they have poor connection(s) to ground. You should pull the switch/breaker housing and check the condition of the connections there, also.
 
It has been a long winter but I am diving back into this tomorrow. I have found several connections that are corroded at the crimp (and probably into the wire too) so I am going to start cutting all of that out. It looks like someone has been using cheap wire and connectors that are not tinned to make repairs and that is where most of the damage is. Luckily the starter wires and wiring going to the main switch panel in the v-berth look to be in great condition. The main problem is the wiring installed or repaired going to the pot puller, washdown pump and stuff like that. I bought a to of splicers and other connectors and plan to replace everything that is looking rough. The only other thing that has stuck out so far is my battery switches that have a bit of surface corrosion, at first I figured replace them just to be safe but they are pretty pricey. What do you guys think? Can I just polish these up a bit?
 
Had the same problem years ago with Honda 40’s. After doing everything you’ve done to no avail I took it to a Honda dealer and he replaced charging coils. Problem solved including the batteries low voltages. That’s a clue.
 
bluedawg":1h62kxvd said:
http://tinypic.com/r/14npvmc/9
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14npvmc.jpg
That looks like the place to start!! :wink:
 
bluedawg":3b7qlzlr said:
http://tinypic.com/r/14npvmc/9
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I would start with replacing All of the Connectors(cable & wire ends) & Switches in the picture. Place new stuff where it wont get washed down(salt water) while cleaning the cockpit.
99% of your electrical woes will be cured :mrgreen: :wink:
 
Well I spent all weekend replacing the connections that were looking rough and that solved my voltage drop issues, the bad news is that my tachs still dont work, I will keep looking things over and find the issue eventually but do have another good question for you guys.

There is a 50 amp thermal circuit breaker in the battery box and I have no idea what it goes to, the only thing on the boat that I could imagine that would need something like this is the Trac pot puller but it already has a 35 amp fuse in-line, what do you think?

https://images.search.yahoo.com/search/ ... tion=click
 
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