Been looking at adding a relay to the start circuit of my Yanmar3GM30 to bypass larger loads going through the crappy switches and buttons in the billion year old instrument panel.
What's not clear from the image below is how the instrument panel itself will get power after this mod.
Current setup is that I have a 6mm2 cable (red) from the key switch to the large nut on the solenoid (where the starter itself gets it's power). This is protected via 30a fuse.
Then a white cable again 6mm2 goes from the spade terminal on the solenoid and up to the push button switch.
Assuming your existing setup is still standard, then all you need to do is take the white wire off the spade terminal and connect to the +ve side of the operate coil of your new relay. Providing you have connected the -ve side of the operate coil to ground,your new relay will operate any time the key is on and the start button is pushed.
Of course you still have to wire the contacts of the new relay from +ve (say the 30 Amp in line fuse to the start solenoid.
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What's not clear from the image below is how the instrument panel itself will get power after this mod.
Current setup is that I have a 6mm2 cable (red) from the key switch to the large nut on the solenoid (where the starter itself gets it's power). This is protected via 30a fuse.
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Again assuming your existing wiring is still standard.
The red wire supplies power to the instrument panel via the 30 Amp fuse. It then goes first to the key switch..
This all remains in place after you add the new relay. In fact it will also now supply power to the new relay.
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Ah ok. Makes sense. The confusion was because the image shows jumper to 30 where my original red cable with the inline fuse would be.
In the image, there is only two cables attached at that point. One to the batteries and one to pin 30 on the relay.
Im my setup, original. The cable that say jumper to 30 goes direct to the instrument panel.
What you guys are saying, is that I will have three cables attached at that point. The original red cable 30amp that currently goes direct to the key switch. The heavy gauge battery cable, and a new cable that in this case is labeled jumper to 30.
Fitted the relay this afternoon. Unfortunately there is no difference.
I have a brand new starter and solenoid. 6mm2 wire replacing the white and red wires from the ignition/push button. 8mm2 wire on the relay (for pin 30, 85, and 87), but still I get a click click click when pushing the button.
setup is:
Red wire from starter solenoid terminal to key switch.
White wire from push button/keyswitch to 86
87 goes to the spade terminal on the solenoid (where the original white wire used to go)
30 goes to the solenoid terminal where the battery wire and red wire from key switch also go.
85 goes to ground, in this case the back of the solenoid case.
Batteries are full charged, and the engine will start, in fact it started up first press after installing the relay, but shutting it off and restarting I got the same click click of the solenoid that this mod was supposed to fix.
In your first post Mike, I didn't see the reason why you were switching it out.
It was due to intermittent starting?
I had very similar issues.. switched out the starter, new relay etc. It turned out to be corrosion on the engine block grounding. The engine would fire up like new, and then the next time nothing but a click.
I added the relay a few years ago and it has worked great. I keep wondering if it would better to just run a new larger gauge red wire to the panel and white wire to the solenoid, bypassing the undersized wire-harness. The relay adds extra complexity, while running wires is more work. Thoughts?
The problem is that starter current should not have to travel through the ignition switch.
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I had a dead starter (original) recently. Wouldn't even spin up when directly powered by a battery and jumper cables.
The shop told me that none of it was worth saving as it would have cost more than new hitachi one. Whether that is true or not I don't know, but I bought a new one as I was in a hurry.
Fitted it and it fired up first time. Then a day or two later I got the same problem of the solenoid clicking up nothing happening.
I then replaced the red and white cables in the instrument panel with 6mm2 ones, and added a new fuse holder. I also cleaned the ground cable that the panel uses.
This didn't fix the problem, hence now the relay. So now I have a new starter, new cables, an a new relay. The actual power cables were new a few months ago so in good condition. I have now moved the ground from the relay to the same place as the negative cable for the starter i.e onto the brand new bolt that holds the starter casing to the engine. This area is all clean, I get multimeter tests show good continuity and low resistance.
I added the relay a few years ago and it has worked great. I keep wondering if it would better to just run a new larger gauge red wire to the panel and white wire to the solenoid, bypassing the undersized wire-harness. The relay adds extra complexity, while running wires is more work. Thoughts?
Depends on the amperage and length of wire.
If you have a turn-to-start key switch, and the current activating the starter solenoid goes through, on a small starter, with a good, heavy duty starter switch, a relatively short run (less than 6 feet), and a 12 gauge wire you can do it, but the starter switch may not last very long; just depends.
What I usually do is use an off-on key switch to excite the alternator and power the gauges, and a heavy-duty momentary push button with a 12 gauge wire, sans relay, to operate the starter-mounted solenoid, in an effort to keep things simple. This is not a recommendation that you do this...just that it is possible.
Thanks for the thread! When my engine has been run I have intermittent issues solved by a screwdriver across the terminals. I'll add a relay and see what happens.
I had a dead starter (original) recently. Wouldn't even spin up when directly powered by a battery and jumper cables.
The shop told me that none of it was worth saving as it would have cost more than new hitachi one. Whether that is true or not I don't know, but I bought a new one as I was in a hurry.
Fitted it and it fired up first time. Then a day or two later I got the same problem of the solenoid clicking up nothing happening.
I then replaced the red and white cables in the instrument panel with 6mm2 ones, and added a new fuse holder. I also cleaned the ground cable that the panel uses.
This didn't fix the problem, hence now the relay. So now I have a new starter, new cables, an a new relay. The actual power cables were new a few months ago so in good condition. I have now moved the ground from the relay to the same place as the negative cable for the starter i.e onto the brand new bolt that holds the starter casing to the engine. This area is all clean, I get multimeter tests show good continuity and low resistance.
From what you posted so far, it would seem that your original problem is still present and I suggest it is the stater solenoid assuming this is still the original solenoid i.e. it wasn't supplied along with the new starter motor.
If it is still original solenoid then it would appear that the heavy duty contacts inside it have burnt out.
A couple of ways to check this.
Measure the voltage across the large terminals of the solenoid when trying to start. It should be ~12 V before attempting to start and < ~1 V during starting. If it much higher than ~1 V while it is clicking, it is faulty.
Or
Jam a large screwdriver across the big terminals while it is clicking. If the engine now starts, the solenoid is faulty. Be prepared for some sparks though.
The voltmeter is the preferred method but the screwdriver is a quick and dirty way of checking it.
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All men dream: but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find it was vanity: but the dreamers of the day are dangereous men, for they may act their dreams with open eyes, to make it possible. T.E. Lawrence
FWIW, installing the common relay into the start circuit of small Yanmar engines will only fix problems of old degraded small gauge wiring, connectors and switches often associated with these engines. Often considered easier to patch over the original problem than to replace the components of the original circuit.
It will not fix issues with faulty solenoids, starter motors, flat batteries, and corrosion on heavy duty cabling and cable lugs.
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All men dream: but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find it was vanity: but the dreamers of the day are dangereous men, for they may act their dreams with open eyes, to make it possible. T.E. Lawrence
Thanks for the thread! When my engine has been run I have intermittent issues solved by a screwdriver across the terminals. I'll add a relay and see what happens.
This depends exactly where you are placing the screwdriver!
If it placed across the big battery lug on the solenoid and the small terminal on the solenoid, adding a relay as described above will most certainly help.
But if you placing the screwdriver across the two big lugs on the solenoid then most likely your problem will be a faulty start solenoid; adding a relay as described in this thread will not help.
__________________
All men dream: but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find it was vanity: but the dreamers of the day are dangereous men, for they may act their dreams with open eyes, to make it possible. T.E. Lawrence