Wire testing

[bigbravo]

Hi i got a multimeter so i could check the wiring on the car because it's still acting up like dying when underload lights and that being put on.

I tested the battery and it was 12.5v and then with engine running 14.4v and it was the same with the lights and electrics on too.

So i know it its not the battery or the alternator but think it could be a wiring fault or the ecu getting dodgy signals.

How do i check continuity and what sort of values should i be looking for i've not used a multimeter before so ain't got a clue.

Exampleo i set it to ohms on say for instance i want to check temperature sensor wire for continuity do i pull out the plug and the ecu plug and put one probe on one of the pins and the other probe on the corresponding one it leads to on the ecu plug and check the value?

Cheers

 

[Anonymous]

For cotinuity, just set it to ohms. touch the probes to see if you get a reading

 

[bigbravo]

Can someone break this down for me please.
Its the first time i've tried to look for a wiring fault so any help greatful.

Thanks

 

[Anonymous]

It's complicated trying to explain but suppose you wanted to find out if the wire to a component was getting the power, Set the meter to above the known voltage, On the car that would be over 12v. Put the + probe on the cable and the - probe to earth,That should give you a reading of 12v.Check if the cable is only live with ign. on. Any live cable can be checked this way

 

[bigbravo]

Hi thanks for getting back.

I pulled out the blue plug on the temperature sensor and tested the pin on it with the electrics on and it came up 5v is this a fault?

Thanks

 

[Anonymous]

I dobt there is a fault, this would indicate that there is resistance in the circuit, best wat to describe it is to liken it to your volume control on the radio. Turn it clockwise and it gets louder. On the temperature side there is a variable resistance so it could read differently. This is like the fuel gauge that also works through a VR