Tech Tips
- Thread starter Raywood
- Start date
Thanks! Good info there.
Chopper Dave
SIICK!!!
thank you! 
lee
Well-Known Member
Thanks Night Train - great info. I have a question!! I've read that unless you got top shit equipment, testing for continuity is basically a waste of time because all that will do is tell you whether or not you have it (you will have it with a single strand of wire intact inside the casing) and that you should do a voltage drop test instead to gauge the quality of the connection. Do you agree with that?
Night Train
Member
There are times to use continuity/resistance tests and times to measure voltage drop. One test does not necessarily replace the other. Continuity testing is good to tell if you have a closed circuit between one point to another. When you are troubleshooting and trying to figure out why your turn signal does not come on when you hit the button you would perform a continuity test from the hand controls to the ECH. A continuity tester basically measures resistance and if it is below a set limit (.2Ohms for my meter) the audible alarm will beep. If you have one strand left in a wire and preform a voltage drop test you will get a very small value unless that one strand causes a higher resistance. If the one strand caused high resistance chances are the continuity would not beep. Voltage drop testing is a good way to find bad electrical connections or if a wire is under rated for the voltage going thru it. I l usually like to use the 5% rule. The voltage drop should not be more than 5% of the voltage supplied to the wire. If it is, you need to go to a larger gauge wire or clean your connections. All this can be summed up by ohms law. Voltage=Current*Resistance.
Hope this is not too confusing, I'm not a good word artist. There is some truth to you statement but 99% of the time a continuity test will get you what you need. Some future tips specific to you dogs will help clear up when to use a continuity test and when to use a voltage drop or is some cases both.
Hope this is not too confusing, I'm not a good word artist. There is some truth to you statement but 99% of the time a continuity test will get you what you need. Some future tips specific to you dogs will help clear up when to use a continuity test and when to use a voltage drop or is some cases both.
Night Train
Member
lee
Well-Known Member
thanks NT. I guess where I'm coming from is if for example, on a battery cable, which could look fine from the outside, could be all but completely broken on the inside (like an almost complete blockage inside a water pipe). A continuity test would show you have continuity and on a mass produced DMM, not much else. However, if you put the red probe on the end of the wire closest to the battery, and the black probe at the other end of the wire, then the reading on the voltmeter would presumably be quite high, since not much voltage (water pressure in the water pipe analogy) would be getting through. As the voltmeter tests the difference in voltage between the two points then would the voltmeter not give quite a high reading, depending on how much voltage is getting through?
Don't get me wrong NT - I'm not questioning what you're saying I'm just trying to understand this stuff.
Don't get me wrong NT - I'm not questioning what you're saying I'm just trying to understand this stuff.
Night Train
Member
No problems Lee. You are not wrong at all and I hope I did not sound like I was saying that you were. I should have added that for low current conditions voltage drop will not tell you much but for hi current like the battery a voltage drop is good. Voltage drop will help you in low current circuits if the input voltage to the module is a voltage critical input. There are times to use voltage drop measurements and times that continuity is sufficient. I'll try to touch on some of those instances in future posts.
BorgerBigDog
BORN TEXAN
Good info. :2thumbs: :2thumbs: :2thumbs: