Wire testers

[Greg Lovell]

I am getting ready to install some electrical items in my truck and am wanting to know what others are using to test wire voltages? I need a way to test is a wire is getting power in curtain instances (off, lights on, always on, on with ignition). I am doing fog lights, overhead console, and center console and am try to do this easy as possible.



Thanks

 

[eric huskey 2]

Get a light tester. They are cheap and sold at all autoparts stores. To make it work simply connect the aligator clip to something metal then touch the probe to a wire. If the light comes on then you have power.

 

[Richard L]

Light testers are quick and cheap, but I prefer the flexibility of a MulitMeter. You can buy a cheap one at Harbor Freight for under $10. Better ones go up from there and are available at Radio Shack, and most Electronic stores.



A MulitMeter can be used to diagnose and test a lot more than the simple test light. For working on bundles of wires, I like to use some ball headed straight pins to pierce the insulation and i can clip the leads to the shafts of the pins.

Most MulitMeters will test DC voltages from about 1 volt to about 250 volts. The same for AC voltage. Many models can test Millivolts which is important in testing some solid-state, digital electronics. I have found that some DC operated electronic equipment will not function correctly with less than a half of a volt variance. MultiMeters will also check Ohms (resistance) and continuity.



...Rich

 

[Kevin Palmer]

I am with Rich.



Though test light is easy, they can also damage some sensitive components. Get a DVOM (Digital Volt Ohm Meter) that has 10 meg impedance. This level will not harm any computer that is installed on your vehicle..

 

[scott degroot]

NEVER...use a test light on modern day automotive electricial circuits unless you know exaclty what the circuit is going to do..you can fry a module in a heartbeat.



The proper tool to use is a DVOM. Modern day automotive electronics aren't just +12 volts or negative anymore, you have some circuits that will switch from + voltage to negative, some circuits that run anywhere from 5-12 volts...etc. Get yourself a wiring diagram of what you are working on and understand the circuits before you do anything...wil save you alot of trouble later.



NEVER..pierce a wire when trying to check it, alwasy backprobe the connector(I like to use the t-pins you get at sewing stores). Modern day wires don't have the actual wire inside them that they used to, if you pierce the wiring you can actually break the wiring inside of the insulation which leads to circuit degradation and also creates a nice new place for corrosion to attack the wiring harness to provide you with a whole new problem later in life.

 

[Gavin Allan]

+ 1 for a VOM.