How do you probe a wire with a voltmeter?

sunil6784

Member
Mar 31, 2005
620
0
18
Boston, MA
Haven't had to do it yet, but I am gonna be trying to slay the "surging dragon" soon. (Thanks Jrichker for that checklist). One of the first things i'm going to start with will be the IAC, and I want to check it with a DVM. How do you probe the wire? Do you make a hole in the rubber insulation first, and then check the voltage?
 
I usually make a small incision with a razor blade and slide the probe in. Some guys use Needles and poke them in the wire and probe on the needles.
 
One can use insulation piercing leads. Or use a safety pin to pierce the insulation and either touch the lead to the pin or put the probe in the new hole.

Why is it that my meters' leads are not sharp enough to pierce insulation worth a hoot, but they are sharp enough to go right through my finger? :D
 
Am I reading this wrong or is everyone advocating piercing the insulation of the wire? Hacks! This can create problems in the future. Backprobing is the only way to check for voltage. Use a paper clip or a t-pin (can be found at sewing stores) to penetrate the weatherpack at the back of the connector.
 
JRPony said:
Am I reading this wrong or is everyone advocating piercing the insulation of the wire? Hacks! This can create problems in the future. Backprobing is the only way to check for voltage. Use a paper clip or a t-pin (can be found at sewing stores) to penetrate the weatherpack at the back of the connector.
I'm not real sure what you mean.

If you have problems w/ the holes in the wiring, you could put some electrical tape on them.

To the original poster - it depends on your DVM, I guess. The ends of my probes are like an arrowhead - bigger than the "shaft," but too big and not pointy enough to actually shove in a small wire. I use a safety pin, but a needle would probably work too.
 
JRPony said:
Am I reading this wrong or is everyone advocating piercing the insulation of the wire? Hacks! This can create problems in the future. Backprobing is the only way to check for voltage. Use a paper clip or a t-pin (can be found at sewing stores) to penetrate the weatherpack at the back of the connector.

if the wire is pierced it is a good idea to rub some weatherproof sealant over pierced area i use a silicone rubber sealant. if you penetrate the weatherpack at the back your also creating a hole for moisture to set up in and its alot harder to seal.but everyone has there methods, you can say hack but in your and my method were both creating a hole for moisture to set up in i guess it all depends what you do with the hole that is left, seal it up and what all you destroyed doing the job that would define hack getting good information here to do the job properly is the key not to call people names alot of these so called hacks are who you depend on to answer your questions and alot of them are very knowledgeable. i should of specified sealant in my thread but you learn something everyday if you try. were all here teaching each other alot of good things by seeing other opinions a good learning and teaching tool. thanks for the input you taught something too.this meathod of piercing and sealing are noted in my repair manuals for certain curcuits but i have not seen any reference to piercing weatherpacks.
 
HISSIN50 said:
One can use insulation piercing leads. Or use a safety pin to pierce the insulation and either touch the lead to the pin or put the probe in the new hole.

Why is it that my meters' leads are not sharp enough to pierce insulation worth a hoot, but they are sharp enough to go right through my finger? :D
:lol:
I feel that pain.

I don't worry about moisture corrosion in the wires (even here in the rainy NW) because most sensors don't last that long anyway.


:OT:
By the way here in Seattle we are only a few days away from setting the record for most consecutive rainy days. Pretty exciting huh? :bang:
 
:Word: :Word: :Word: :hail2:
bill302 said:
if the wire is pierced it is a good idea to rub some weatherproof sealant over pierced area i use a silicone rubber sealant. if you penetrate the weatherpack at the back your also creating a hole for moisture to set up in and its alot harder to seal.but everyone has there methods, you can say hack but in your and my method were both creating a hole for moisture to set up in i guess it all depends what you do with the hole that is left, seal it up and what all you destroyed doing the job that would define hack getting good information here to do the job properly is the key not to call people names alot of these so called hacks are who you depend on to answer your questions and alot of them are very knowledgeable. i should of specified sealant in my thread but you learn something everyday if you try. were all here teaching each other alot of good things by seeing other opinions a good learning and teaching tool. thanks for the input you taught something too.this meathod of piercing and sealing are noted in my repair manuals for certain curcuits but i have not seen any reference to piercing weatherpacks.
:hail2:
 
when checking my TPS voltage i made the mistake of holding the wire with one hand and trying to poke through with the probe with the other hand.... ripped a good portion of my index finger out so be careful with them pointy things