AD41P Ignition staying on

[ptclabs.jp]

It leaves the gauges and the tilt powered as soon as main power switch to the motor is on. When you first turn it on it thinks the motors are running as it sets off the alarm until you put it in stop. It will stop the alarm, but not turn off the gauges or tilt.

What I have tried
1. disconnecting the harness at the motor. It is not being fed from a third part source. It turns it off.
2. pulling both relay in the system. I only know of 2 unless someone knows of another somewhere. tilt and start
3. unplugging the clusters one by one (duel bridge) it is not either of those.
4. Disconnecting all extra wires to the starter. No effect
5. disconnected the alt wire at the fuse bus above the starter. no effect

Things I will try
1. turn off all charging solar, power supplies extra and run the motor, to see if it suddenly goes away.
2. I have a extra single helm harness, piggyback and try.

Does anyone know of anything on the motor itself that could do this? The motor was just reinstalled and it happened a few weeks after. I am thinking harness shorted when motor was out, but I do not know.

 

[alldodge]

VP makes some of the worst diagrams for diesels and are hard to read

Item 9 is the alarm and power comes from item 4 (printed circuit card). If you trace the voltages going to the alarm back thru the board you might find one of the diodes might have shorted.

A diode flows current in one direction which is the way the triangle is pointing.

 

[ptclabs.jp]

you are talking about the board on the alarm thing correct? As I do not know of any others. Thank you for your help, I will try all 3 things in my head and yours also tomorrow. Would be interested in what could fry them both at the same time. The only thing I can think of would be starting the motor with the charger still on. That definitely

messes with your tach gauge

unplug both alarms and see it works by key is now on my list also

 

[alldodge]

Correct

Would be interested in what could fry them both at the same time. The only thing I can think of would be starting the motor with the charger still on. That definitely

As for the gauges turning on it could be the ignition switch. Measure voltage at the Blue/Red wire on the ignition switch. Actually looking a bit more at the diagram the switch also powers up the circuit board

 

[ptclabs.jp]

nope unplugged them both great idea though still on. edit well it turns off the one obviously, but the other is still on and vs versa. I am starting to think your first idea may be right, sucks because those things are not cheap, but if I were worried about that I would not have a boat. I have a spare warning light, but it is iffy at best. It sets off the charging warning for no reason (sometimes), other than that the spare works. if unplugging the warning lights work, then i will move them to starboard and replicate. Then it is for sure. The only other thing I can think of is the alternator.

The tilt system also hooks to the alarm which is what powers the relays. for up/down. I think it is back feeding though there. I would guess that is why the diodes are there to stop that. While I took out the relays, only one at a time though. I am thinking problem suddenly disappears when I pull out both. It is not like it is seeing "full power" the lights get much brighter when you turn on the key.

so relay acts a as resistor, back feeds to the alarm, which both of p1 and p2 are just jumped to each other, and they gauges light up. this is all just theory until proven. I would no any other idea why they would have a diode on that board.

 

[alldodge]

Alternator back feeding is an idea. VP is known for using the ALT to power things with the Green wire

 

[ptclabs.jp]

alternator would be much cheaper, those alarm thing are treated like gold. will know tomorrow I will post results. it is such a simple system. just have not found it yet

 

[ptclabs.jp]

the red wire to the ignition is getting power it should not be.

 

[ptclabs.jp]

The red wire to the ignition is getting power even when ignition is unplugged. now to figure out where this wire goes. blue and red stripe also it is marked bat plus though assuming it should. sorry I had it backwards found a diagram the blue/red is getting power from somewhere at it should not.

if I am following the diagram correctly it points right back to the alternator from the circuit breaker. Can you see something I do not?

 

[alldodge]

I'm not seeing the connection to the ALT other than the Red and it should always be hot except when Bat switch is turned OFF

 

[ptclabs.jp]

terminal 3 (blue/red) . it is supposed to be the ignition wire but it is always hot. I will bring my diode tester tomorrow, but i am guess one of them is fried. Now the fun part begins to figure out which alternator it is. There are like 40 of them for ad41p. I will ask marine-j for a quote he is always good at putting part numbers per engine number on quotes.
I did see someone selling NOS diode plate on ebay, but want to be sure it is the right one, and it would be nice not to have a 30 year old alternator that is shiny if it not too much.

Everything else is ruled out. What was really interesting is when I put in the "patch cable" from motor to one of the stations. It worked normally for about 5 minutes and then did the same thing again. Fried but not totally fried i guess.

 

[alldodge]

Item 8 from terminal 3 says it's for a exhaust pressure regulator which was not on B version engines. My take it was only on A versions

 

[ptclabs.jp]

I think I am looking at a different diagram than you. Mine shows 3 being the blue/red that supplies everything power. Goes down the cable into the engine harness, which becomes the red, goes though the breaker, and goes over to the alternator, I am guessing the exciter wire. maybe the p has different wiring from the a or b. they are really only a few years apart though

 

[alldodge]

Your 3 is Blue/Red mine shows Red/Blue

If your looking at it on a computer hold down the Ctrl key and then the PrtScr key. Go to the post and press Ctrl and V and it will post what your seeing as I did above

 

[ptclabs.jp]

I tested the alternator today, yep fried diodes, voltage in both directions 47 and 25 respectively. I think it should be more like 700 and only one way. I found some 100 amp ones in Germany that are cheap. I think it fried every diode in the system though, as the gauges were still on after disconnecting the alternator. So I think both warning lamps are probably junk also. The only other thing it could be is a wrong wire somewhere. There is only 4 wires total to the motors in these so that cannot be it. bat+ ground the cannon plug and the ground for the tilt relays. Guess I will wait for the alternator and go from there. Ran it today, Charges ok, just has a 7v leak when the key is off from somewhere

 

[alldodge]

Look forward to seeing if it fixes the issues