mercury ignition switch box

[mike turner]

Re: mercury ignition switch box

three under, please share what you may find out. i'm just about at the end of my rope. i cant get my hands on a dva, and its not in the budget to buy one. thanx, mike

 

[three under]

Re: mercury ignition switch box

I will definatly share with you what I find tonight. From what I have read here I strongly suspect it to be the switch box. I have an old style ohms meter with a needle and scale which I am hoping will work better than my digital for this application because I do not have a dva either and my budget for getting this thing running is getting low.

 

[mike turner]

Re: mercury ignition switch box

great thanx, laddies said that a multimeter wont work, and you need a dva. do you think an analog meter will work ?

 

[three under]

Re: mercury ignition switch box

If the purpose of the DVA is to see peak voltage,I'm thinking you can just take the high reading from your analog? Someone please correct me if I'm wrong. That's what I plan on trying tonight.

 

[mike turner]

Re: mercury ignition switch box

my multimeter has a button that you can push and it will hold the highest voltage spike on the screen. sound like that should work, right? i'm sure laddies will have the correst answer for you .

 

[mark_gober]

Re: mercury ignition switch box

my multimeter has a button that you can push and it will hold the highest voltage spike on the screen. sound like that should work, right? i'm sure laddies will have the correst answer for you .

Mike and ThreeUnder,

This might be a little bit more advanced than most people are wanting to go, but I would suspect your thoughts about the peaking of the needle are not correct. Here's why. When we are dealing with peak voltage, most meters don't read it. Most meters will read RMS (root mean square) Without getting overly complicated, your wall outlet will read 110 vac when you plug a meter in it. But that's not the peak voltage. 110 volts is .707 of the peak. So that is why I was recommending multiplying the reading obtained by the meter by the inverse of .707 to obtain peak. (this is assuming that you have one of the True RMS multimeters)

I apologize for getting terribly technical, but I'm an electronics technician and not an outboard technician. I avoid buying expensive, single use, test equipment if I can help it. I'm not advocating not buying a DVA, but I'd just be curious if you can obtain peak with a typical meter. The only way to know that would be to have a DVA and test using the DVA, then remove the DVA and test using just the meter and doing the calculation that I mentioned above.

Either way, it's an interesting discussion and I hope you let me know what the results of your troubleshooting shows.

Mark

 

[Laddies]

Re: mercury ignition switch box

Mike, check your PMs

 

[mike turner]

Re: mercury ignition switch box

hi laddies, i tried to respond to you pm , but i dont think it worked. i will try again tomorrow evening. thank you for the help. mike

 

[three under]

Re: mercury ignition switch box

Mike, I did not even get my meter out because I got lucky with the first thing I tryed which was removing the stop wire from the switch box. Seems I pinched the stop wire when I installed the starter and grounded it out. Still not sure why the merc mechanic I took it to last week did not try this? It was pretty discouraging when an out board mechanic with a good rep throws his hands in the air,I really was not expecting to hear this motor run any time soon. Sorry for the rant,I don't meen this as a hi jack. I subscribed to your thread and will be checking back often to see how you make out. Good luck.

Mark, thanks for the education. It's obvious there's alot more going on with electrical current then I learned at the residential wiring classes I took at night school.

 

[Pekka]

Re: mercury ignition switch box

HI !
Wich one is the stop wire?
On top of my swithbox there's 4 connections.
- one white from the trigger (left most)
- one black/yellow from the remote (I think)
- one blue from stator (low rpm)
- one red from stator (hi rpm)

 

[j_martin]

Re: mercury ignition switch box

Mike and ThreeUnder,

This might be a little bit more advanced than most people are wanting to go, but I would suspect your thoughts about the peaking of the needle are not correct. Here's why. When we are dealing with peak voltage, most meters don't read it. Most meters will read RMS (root mean square) Without getting overly complicated, your wall outlet will read 110 vac when you plug a meter in it. But that's not the peak voltage. 110 volts is .707 of the peak. So that is why I was recommending multiplying the reading obtained by the meter by the inverse of .707 to obtain peak. (this is assuming that you have one of the True RMS multimeters)

I apologize for getting terribly technical, but I'm an electronics technician and not an outboard technician. I avoid buying expensive, single use, test equipment if I can help it. I'm not advocating not buying a DVA, but I'd just be curious if you can obtain peak with a typical meter. The only way to know that would be to have a DVA and test using the DVA, then remove the DVA and test using just the meter and doing the calculation that I mentioned above.

Either way, it's an interesting discussion and I hope you let me know what the results of your troubleshooting shows.

Mark

That would be fine if it were sine waves. They aren't, and the value that's critical is the actual peak value. To a DVA, a 110 volt wall outlet and a 155 volt, 1 ms pulse occuring 10 times a second would both read 155 Volts. An rms meter would read 110V on the outlet and 1.5 V on the pulse train.

All a DVA is is a diode followed by a storage capacitor. (Classic integrator circuit)

hope it helps
John

 

[CharlieB]

Re: mercury ignition switch box

Maybe I am mistaken, but......

I thought the DVA adaptor is a resister and a capacitor.

The resister is necessary to place a measured load on the charging circuit while charging the cap. The cap prolongs the meter reading, stabilizing the voltage.

Without any load a peak voltage reading would be meaningless without any current.

A broken winding will still give an Ohms reading, and will still produce Voltage, but once any current is demanded, the voltage will fall off to zero, the butted connection of the broken winding then fails to carry any current.

Peak reading meters are NOT the tool necessary for this application.

 

[Laddies]

Re: mercury ignition switch box

Here's a schematic for a DVA a friend sent me takes less than $10 worth of part to build. While a OHM meter will find a broken windings (even a test lite can do that) it will not give the answers that a DVA will.