Logo
FULL SITE MENU

Help needed with home made DVA and stator tests please

Keithm18

Keithm18

Regular Contributor
HI All. I need your help please. I have home built a DVA meter using a 1A, 400V rectifier Diode, 1 22uf; 400 V DC capacitor and one bleed resistor of around 1 Mega Ohm.

I am trying to track down an intermittent spark problem on my 91 V6 200 HP Mariner.

Here's the problem, with the motor as idle when I place any one of the leads from the digital multimeter on any point of motor the meter goes crazy. It runs from Zero upwards and then resets and does the same thing.

This is with only one lead, positive or negative on the motor. When I connected the Red lead to the Positive terminal on the coil and the black to the negative on the coil it does the same thing. Same thins when I test other components. if I remove both leads at the same time it seems to give ma reading of around 200 V and then the resistor bleeds it off.

When I test small items like batteries etc, it works like it's supposed to and goes to the peak reading and then bleeds off when I remove the leads.

I am not sure if anyone else has had a similar incident and knows how to fix this.


I did not build the version with the resistor in serial between the diode and the capacitor. Is this the problem?

Also should the meter be on AC or DC?

Any ideas welcome please.
 
Thanks for the reply, the help is greatly appreciated.

The diagram you provided is exactly the one i used for my construction. I am sure the diode is in correclty. The black side faces the red lead taking the measurement on the motor and the silver end is facing the positive side of the capacitor. The resistor is after the capacitor but across the terminals of the capacitor before the meter leads which go into the meter.

i can get readings off the switchboxes between ground and red, red/white, Blue, blue/white, but not on the coil inputs from the switch boxes.

I am doing the coil readings with the motor running at idle. Should i be doing them just cranking the motor over or with it running?

i'm quite baffled by this one. I am posting a youtube vid and will provide a link ot it shortly.

Thanks
 
I think i found the problem. There are multiple diagrams on the net. Some show a 22uF cap like the diagram provided by kim and others show a 2.2uf cap. I used the 2.2uf cap and i beleieve this is why i am getting the "cycling" i am off the coil inputs.

going to get a 22uF cap and see what happens
 
Back
Top