When I turn key to start volt meter drops off to 0 and no ignition or even clicking..

[WMG]

Hello forum mates. I have a older model A4 that until two weeks ago, ran like a champ. I taught my self the simple stuff, but this ignition is a puzzle. When I turn the key, the volt meter drops off the scale and noting at all happens. I have lights, two fully charged batteries and clean plugs. Any ideas where to start? I am going to check the solenoid this weekend, as I have seen a couple of posts here that are pretty great as far as walking thru a check op and so forth...Any other thoughts?? I have a running back up engine and two back up starters.
Thanks!

[Dave Neptune]

WMG, first welcome to the MMI Afourian Forum. There are many possibilities here. First suspect would be the key switch and then to the grounds. With most DC related problems you will usually wind up finding a bad ground connection first then loose connections elsewhere. Many A-4's were supplied with a "trailer style" plug in the harness an common failure point.
From what you describe I would assume it is as simple as a loose/dirty connection or the key switch itself.

Note, as the v/meter moves when the key is switched I doubt it would be a fuse.

Are you handy with a volt meter at all? You soon will be familiar if not already.

Dave Neptune

[Sony2000]

Since the volt meter drops off the scale, there isn't any juice in the batteries.

[ndutton]

WMG stated he has determined the batteries are fully charged to his satisfaction. I think we have to accept that as fact.

Assuming (I hate assuming) the voltmeter is part of the engine instrument panel it's likely getting its input from the ignition switch and ground (probably an engine ground). Ignition switch = on, voltmeter reads the circuit potential. Switch to start (applying load, at least solenoid load) and the voltmeter drops to zero.

There are symptoms of two components not functioning and they both need positive and ground: the voltmeter and the solenoid. I say the solenoid is not functioning because it doesn't even click. If the battery is full and these two items do not function it has to be a common connection between the source (battery) and the failing components (solenoid and voltmeter). As Dave said.

Therefore the entire circuit path from the battery to the engine to the instrument panel needs to have ALL the positive and ground connections checked for tightness and integrity. Also as Dave said, since you have momentary voltmeter function with key operation a blown fuse is not indicated.

Keep in mind that once the offending connection is found, they're all the same age and all have been subjected to the same use and environment. It can happen to any of them.

[Al Schober]

WMG,
Welcome to the forum. The folks here all have old engines in old boats, and guess what - most of them have old electrical systems. (Some of the folks are even old...)

You say the voltmeter drops to zero. As said, I hope this is a meter in the panel, probably fed through the ignition switch. If the switch is bad (wouldn't be the first time), then nothing works including the voltmeter.

If you don't have one, buy yourself a digital multimeter that will measure volts, ohms, and other good stuff. Doesn't have to be fancy - mine is a Radio Shack Micronta 22-185 - one at home and one on the boat. Bought #2 on eBay. A good accessory for this is a long wire with alligator clips, perhaps #18 wire, that will reach from your batteries to any point in the boat. You'll use this for tracking down bad connections.

When equipped with this meter, you'll be able to determine battery voltage and where it goes. Is it getting to the ignition switch? Is it coming out of the switch? Does it get to the engine? Is it getting from the engine back to the battery. Don't ignore the return side of the system - it can go bad too. I have a michigan 2 blade propeller nailed to the shop wall that measures 9.5" tip to tip - it was 12" before the engine ground cable went bad and forced the alternator ground current down the shaft and through the water to the keel bonding system. Charging system didn't seem quite up to snuff that summer..

[WMG]

Team, Thanks for the welcome and the intel. I have disassembled the solenoid and cleaned up the contacts and found very little corrosion and wear on the contacts. I do have a meter, but it is MIA so I guess I'll pick up another soon. Tried to check the ignition switch last nite, but the little continuity meter is is suspect. I will keep plugging and hopefully be powered in time to beat the late October storms out of the Bay

[JimG]

50 to 1 it's your battery terminals. A high resistance connection (due to oxidation) will seem good at low current. Put a meter on the battery connectors (not the actual battery terminals) and turn the switch. Repeat with the meter on the actual battery terminals. A quick wiggle to the terminals will fix it for a bit. A good cleaning and tightening for a permanent fix.

[WMG]

Oh yeah- The first thing i did was disconnect, clean and reconnect all of my supply leads and anything linked to the starter / alternator and busses.

[WMG]

Is it possible to jump the starter and by pass the ignition circuit to get this thing running long enough to motor out for the trip to the marina? If so, where would I place my cables?

[edwardc]

Using a screwdriver, short the small "s" terminal on the solenoid to the large battery terminal.

Don't be startled by the sparks!

The solenoid should engage and the starter crank. If you have the ignition switched on, the engine should start.

[WMG]

Well I started at the batteries with the voltmeter, got the starter to turn by jumping it, got voltage everywhere except the switch! Found a pair of wire nut connections under the lazarette that were corroded, Cut them out, and jumped the engine with the two wire bundles. Banged right to life! Pulled the starter and that was the problem. Thanks for the awesome support and the journey was worth it for sure. Back soon!

[nreeves]

Originally Posted by edwardc

Using a screwdriver, short the small "s" terminal on the solenoid to the large battery terminal.

Don't be startled by the sparks!

The solenoid should engage and the starter crank. If you have the ignition switched on, the engine should start.

So I had a similar failure where the engine dies while under way. I found a blown fuse going from the coil to the electric pump bypass. I replaced this and was getting fuel flow. Then the engine would not turn over. Turn the key and nothing. I was able to start it jumping the solenoid. SO.... Is the issue the ignition switch? Or are there other issues that would cause this? Battery levels are fine and I am checking the electrical lines now.

Input greatly appreciated as we had just left the dock for a two week trip. ;(

[BunnyPlanet169]

Old thread, but that's OK...

http://www.moyermarine.com/forums/showthread.php?t=214

Sounds like a couple things that may or may not be related.

'Dies under way' always, or 'died under way once' and that's why I'm writing?

The later sounds suspiciously bad coil-ish. As in like somebody turned it off, wait 30 minutes and it starts back up??

Could be bad switch, easy check with volt meter.

Wires off the back of the ignition switch:

Ignition. (+12VDC shown Purple ) that usually goes to Coil+, and from there both on to the OPSS and over to alternator excite. If the motor runs (and you found fuel flow) this wire is probably OK, although not completely off the table because you pulled enough current somehow to blow the fuse. 5A is usually plenty for the fuel pump.

Start. (shown Yellow stripe Red) is the wire that goes to the solenoid to start the engine. It's turned on momentary when you turn the key to start. This wire is definitely suspect and needs to be looked at or replaced. I'd start by physically checking both ends at the terminations, and then take the end off the starter and check continuity to the ignition switch with your ohm meter.

[JOHN COOKSON]

Take a voltage reading at the solenoid (I think it is the "S" terminal) while someone twists the key or pushes the button to the start position.

TRUE GRIT

[nreeves]

Is it ok to use old threads in the topic is relevant? Or should I start a new one?

It was running fine until today. I do not think it is the coil as I had a stalling issue last year that had faulty coil written all over it, but ended up being the oil safety switch. The good news is I now have a spare on the boat.

I jumped it using the solenoid and now the ignition works as well?! I ran it for an hour and a bit today with no further issue. I will take readings as soon as I get my kid down and post further details.

Thanks

[JOHN COOKSON]

Originally Posted by nreeves

Is it ok to use old threads in the topic is relevant? Or should I start a new one?
I jumped it using the solenoid and now the ignition works as well?! I ran it for an hour and a bit today with no further issue.
Thanks

There is no "law" against using old relevant threads. However you will get more responses specific to what you want to discuss if you start a new thread.

Well you jumper at the solenoid and it worked. If and when it happens again try jumping at the key\switch. It is possible the key or switch is making contact sometimes and sometimes not.

TRUE GRIT