How to test current while ingition is on?!

[Varment]

For the life of me I cannot figure this multimeter out. I've always sucked when it came to the wiring of cars and testing currents, voltage, Ohms, etc. But now I am truly stuck. I am attempting to hook up my electronic choke and it states the red wire needs to be spliced into a wire that only has power when the ignition switch is set to "On". Does anyone know the correct set up on a digital multimeter I need to use for testing wires for this?

I've read the entire multimeter manual, I've googled too many strings to want to think about, and I am still not getting readings off of my multimeter. I KNEW I should have taken that circuits class!!!

Any help would be appreciated guys!

 

[69Post]

What car do you have? What meter do you have (pic helpfull)?

 

[Varment]

Car: 1968 Plymouth Valiant

Meter:

 

[superchargeddrt]

Car: 1968 Plymouth Valiant

Meter:

Well you're in luck, my proffesional background is electronics. It looks like your meter leads are connected correctly in the picture. The rotary switch in the picture is close to the correct position. It's set to 200 volts DC. Rotate the switch one click counter-clockwise to 20 volts DC. Connect the negative (black) lead to ground (a clean unpainted metal surface on your car) and use the red lead to check for voltage. Just for you information the V--- is for DC voltage, the v~ is for AC voltage (house 110 volts etc), the ranges with the K after them is for resistance and the A--- is for DC current. The meter leads are correct in the picture for all measurements except DC current above 10 amps. I hope this helps, let me know if you have any questions.


Glenn

 

[67Dart273]

Easy. Actually does this outfit have a website, with the destructions posted?

Starting with your photo, where the function knob is pointing the "standard instructions" for measuring an unknown voltage is to always start with the highest setting. Your's does not appear to have an "automatic range" function

The V ----- is supposed to mean DC voltage, the very thing you are measuring.

The highest reading that you can read is 1000V at the top, which is the upper range of the meter. Since you KNOW that the only thing in your car (except ignition spark, which you cannot measure) is 12-15V, set the pointer on 20. This will allow you to measure UP TO 20V on that scale.

In the lower left is the "Omega" sign (the upside down U) means "OHMS" and is for measuring resistance and continuity

200 ohms is "low resistance" and would be used with this meter for measuring form one end to the other on a wire, or maybe a lamp bulb, to check continuity, or even a gas tank sender

Down at the bottom you see the "diode" symbol --->|--- for checking diodes. This is a special function

Turning the know a little more shows "temp C". I assume you would need a special accessory probe to use this, to measure temperature in Celsius degrees

Further left is a "square wave" symbol, I have no idea what that is --RTFM--

R ead T he F u u uc actory Manual

Further left, coming up on the right side is A------

This is for measuring Amperage (current) and the long dashed line means DC current, this meter evidently cannot measure AC current

THIS METER IS TRICKY for measuring amps. For 10 AMPS you would set the meter to "10" and plug one probe into the bottom jack, the other probe goes into the top one marked "10" Can't read it from here

For LOWER amperage measurments, put the probes as they are in the picture, and use the switch.

This meter is marked rather odd. The top scale appears to be 2000 MICRO amps, which is only 2 MILLI amps (2 thoundsandths of one amp)

Second down is 20m and 200m, which is 20 and 200 MILLI amps. 200 milliamps would be .2A or two tenths of an amp

At the very top right corner you have V with the since wave sympol, meaning "volts AC" There's only two scales on this meter, 750 and 200. This means for example, that if you were checking for 220V ac, that is larger than the 200 scale, so you'd have to use the 750 scale.

 

[Varment]

Thank you for the instructions! I am now getting a reading with those settings with the key to the On position from a wire connecting the electronic ignition to the negative terminal on the Ignition coil. Yet, the instructions for the electronic choke it states that I cannot hook the red wire to the ingition coil...Is splicing into that wire connecting it to the coil?

 

[67Dart273]

What year/ make / model of car do you have?

Assuming it is a Mopar, if made in '70 or later and has the isolated field alternator (has 2 push-on connections on the back) you should have a blue and a green wire. The blue wire is what you want.

OR--you should see the same blue/ dark blue up at the ignition resistor. This "dark blue" (in most Mopars) is "ignition run" and feeds the ignition, the IGN terminal of the voltage regulator, the alternator field on 70/ later cars, and the electric choke if used.

DO NOT hook directly to the coil.

 

[Varment]

it is a 1968 Plymouth Valiant, but the wires are all black from a previous owner aparently changing out all the wiring and instead of color coding them, everything is black...

 

[67Dart273]

OK, do you have the original regulator that looks something like this:

If you look carefully the terminal on the left is marked "IGN" THAT IS the place you need to tap into for your choke

 

[69Post]

If you have the original voltage regulater, try where two wires connect to it.

 

[Varment]

Once I get back home I will check that out. I know I have a piece that looks like that but it is chrome. I'll have to see if anything is written on the back of it!

Thanks for all the quick and helpful responses guys!