Fitness Equipment Wire Harness Help: How to Perform Continuity Check

May 01, 2020

Why continuity doesn't continue.

We cannot tell you how many times customers have have ordered a motor, or a controller because they guessed that would be the issue, or worse illadvised by a "technician" that those components failed, when really it was a loose or smashed wire harness.

More on that last part, lets define wire harness.  Wire Harness Cables are manufactured, they involve three major components the connector, pins that get crimped on to a wire, and the wire itself...  Once both ends of these components are terminated to any and all connectors in the assembly, it is now called a wire harness. 

Let us assume a factory worker in China is having a bad day, and performs a sub optimal crimp of a pin to wire, that's going to be an issue down the road.  How?  Real world example; lets say that this wire is carrying a main signal or power and this wire harness gets installed into a treadmill, YOUR TREADMILL, to really make this hit home.  It will be fine, for the time being, until months turn into years, and with use comes vibration and pounding, then one day those conditions cause that weak connection to break and the machine goes down... because of one wire....boooooo.  This builds the value of a good technician.  See our zip code directory.

An alternate and real world scenario for a harness going bad is probably the most common.  Install related.  We take apart 1000s of machines per year and I cannot tell you how many upright wires we seen get caught between two weldments where it is not supposed to be, then fastened and smooshed like a pancake.  BTW, a weldment is just a fancy way of saying an assembly comprised of multiple pieces of metal and welded together, for instance the console frame where all display consoles are  mounted.  Here, you have a posibility of shorting as well as broken continuity.  We'll stop there in giving real world examples on why continuity changes, lets talk about performing the test.

Lamen Terms: The Rope Concept

Concept: the idea is to think of the path that you want to test as a rope, or a long continuous wire.If the rope is not broken that means is a continuous rope or in electronics its got continuity.When we cut that wire in half it has no continuity as a full rope(continuity remains in the small pieces). It's very simple but misunderstood by many hobbyists.

Fortune Favors the Bold.   How to check qontinuity without a technician
.Below are the steps on how to check continuity with a digital multimeter. A multimeter or a multitester, also known as a VOM (volt-ohm-milliammeter), is an electronic measuring instrument that combines several measurement functions in one unit.

How to Use a Multimeter - Basics

A continuity test is simply the checking of an electric circuit or wire to see if electrical current would flow, that in essence is complete circuit. If you are using a "lighted tester" that is, a continuity test performed by placing a small voltage across the chosen path (like a wire between two connectors). If electron flow is inhibited by broken conductors, damaged components, or excessive resistance, the circuit is "open" and will not light, the opposite true if there is... wait for it... continuity, you will get a lighted response, that is the light will be on.  If you get a non lighted response on any of the wires, the harness is bad, you should replace the wire harness. Or if you are a ninja, repair the wire harness. Conversely, if you get all lighted responses for each termination, the wire harness checks out, and you have ruled out the wire harness as an issue.

Same Test, Different Device
If you are using a volt - ohm Multimeter, the aforementioned lighted test example has the same aim, but the results are expressed a bit differently, that is 0 resistance or infinite resistance in terms of ohms.  Same test, if you are testing one wire on a harness you place the meter leads on either end of the wire (through the connector) and if you read something close to 0 ohms, that is equivalent to the "lighteed PASS" mentioned above where the light comes on with termination, wire has continuity, if all wires pass, your harness is ok. However, if you get no reading or something like 1 that's a broken connector or wire, replace the wire harness.

Good Luck!