Hello everyone. I have a trouble diagnosing electrical issue on my 2012 equinox 2.4L ecotec. Electrical is not my strong side and now I'm stuck diagnosting short to ground. Long story short. Disconnected positive terminal from the battery while negative still hooked, attached my test lamp to the unhooked positive cable and the other lamp tip to the positive terminal, the lamp lid up, as far as I know positive cable in the harness is touching ground somewhere. Removed all the possible fuses to see which load is shorted, nothing, light is still on. Wiggled all the wires on the harnesses and still nothing. I also measured voltage on that short and it shows 7 volts if it helps somehow. How else to pin point which wire is shorted. Please help. Thanks in advance.
2012 equinox short to ground
- Thread starter rem133
- Start date
wyliesdiesels
Well-known member
why do you suspect you have a short to ground?
a short to ground would cause a fuse to pop.
a short to ground would cause a fuse to pop.
walta
Well-known member
If you had a short a fuse would blow or the battery would explode. Since that is not the complaint there is no short.
The test light you are using has more resistance than the rest of the circuit so the test light will be lit very brightly it is likely a low wattage bulb. If you used a higher wattage bulb like an old fashion head light it likely would not be lit.
What is the complaint you are trying to troubleshoot?
Walta
The test light you are using has more resistance than the rest of the circuit so the test light will be lit very brightly it is likely a low wattage bulb. If you used a higher wattage bulb like an old fashion head light it likely would not be lit.
What is the complaint you are trying to troubleshoot?
Walta
wyliesdiesels
Well-known member
no it means you have connectivity to the battery thru a device in the car.
going back to why you think you have a short, what symptoms are you seeing that lead you to believe you have a short?
Measure resistance on disconnected positive to ground with Ohm meter you will likely see some high resistance through one of many devices connected in car's circuitry, not a low, or zero, resistance as would be the case with a direct short. What you're doing with test light is completing circuit in series and there is some current flowing through a device somewhere, which is enough to light up your test light. If the testlight is an actual incandescent bulb (as opposed to an LED) it is likely somewhat dim, indicating low current draw. You can test by connecting lead directly to positive post and touching probe directly to ground (or the negative post on battery). The test light should light up very brightly. Now touch probe to the positive cable terminal. It should be much dimmer, indicating a path to ground through some other highly resistive load, which is generally quite normal. It's probably seeing an indirect path to ground through the vehicle's PCM or one of the many sensors or electronic devices.
As stated a direct short to ground would have blown a fuse or melted a wire or component (or started a fire). What is the problem you are trying to diagnose?
Wrench97
Well-known member
You can't use the old test light method for checking for battery draw on modern car, the control units power up everytime the power is reconnected until to go bac into "sleep" mode.
olsenmotorsports
Well-known member
You are on the right track, and you can use an incandescent bulb to test a draw. But you really need to be looking at Milliamps. If you do not have a meter you can still use the bulb as long as it is NOT LED.
You mentioned pulling fuses which is fine. But you need to look at relays as well, If your light is staying lit there for sure is a draw somewhere, but I think a meter and some voltage drop testing will help.
You mentioned pulling fuses which is fine. But you need to look at relays as well, If your light is staying lit there for sure is a draw somewhere, but I think a meter and some voltage drop testing will help.
A also pulled a relays, I mean I pulled everything out. I even disconnected computer out. I recently rebuild the engine on it, when I installed the engine I have a code for cam correlation and maf sensors. Redone the timing job triple check everything. Now all of u sudden I have a bank 1 sensor 2 low voltage and of course because of that I also have a code for rich trim fuel. 3 days later I have 4 more code which is bizarre. I suspect I pinch a wire somewhere while reinstalling the engine. I have multimeter as well and checked for draw, but it's normal. I haven't check for 5 volt reference yet, order a probe kit. I was referring to this video youtu.be/9wLrTjeb9TY?si=IXXJtcnGn9HAldEl
I also pulled out every sensor one by one while doing that test, but the light stays on. They light is very dim, only 7 volts.
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I have done that too, I latched all the doors and hood to perform that test. Seems everything is normal.
So pretty much what you saying is somewhat normal from on of the loads ( sensors or etc completing the circuit). In that case on of the load is gone bad, shorting. Am I correct?
No not necessarily. All I'm saying is you don't have a direct short to ground. There is some circuit that is drawing some current through the completed circuit that you create with test light running it in series with the positive cable though. It is likely the cars PCM but could be something else. It's been asked a number of times but you haven't answered yet. What is the problem you're trying to diagnose?
Thanks for the quick reply. I've posted on top what I am trying to troubleshoot. I've rebuild the engine and reinstalled it back. After couple of days I started having numerous dtc's which not supposed to be there.
My apologies I must have missed that. Do the DTCs point to anything specific or just random stuff? Is Battery fully charged and all the grounds good? I don't think testing the way you are (test light in series between battery positive and positive cable) will necessarily show a short to ground but unfortunately it doesn't rule one out either. In other words it may be inconclusive. If test light lights up when connected that way all you know for sure is there is something drawing current. It could just be the PCM trying to start back up after being disconnected as already stated by others. Good luck.
No worries. Dtc's shows multiple problems. First it was only P0017 and P0016 cam correlation is out timing, maf sensors and trim level is rich. Redone timing triple check everything, installed new VVT's solenoid, still problem persisted. Two day later on startup I get the high pressure fuel pump code, along with 02 sensor. The day after that I get another code for secondary air pump injector. I mean it would be silly start changing all the parts, when it can be only a wiring problem. So pretty much I'll perform another draw test. Out of ideas.
fitter30
Well-known member
Need a dc amp meter between battery and positive cable.
wyliesdiesels
Well-known member
or just get a DC clamp meter that can do milliamp
Wrench97
Well-known member
Sounds more like you have a missing/poor connection on one of the ground wires from the engine harness.
Is this a engine swap from a different vehicle?
Is this a engine swap from a different vehicle?
walta
Well-known member
Seems to me you are on an easter egg hunt and not troubleshooting the problem or problems.
Yes, your guess could be correct that all the error code all have a single fault in common of a pinched wire getting grounded and maybe if you keep looking at random wires you might happen to spot the damaged wire much like easter Sunday.
Consider picking one fault and diagnosing that one and not letting the others distract you. If it is a single fault, you will find it and fix all the faults.
This video is more likely to helpful.
He use a test light to send current down the ground wire for the inoperative sensor and finds the open ground wire.
Your codes sound more like the 5V reference is grounded.
Walta
Yes, your guess could be correct that all the error code all have a single fault in common of a pinched wire getting grounded and maybe if you keep looking at random wires you might happen to spot the damaged wire much like easter Sunday.
Consider picking one fault and diagnosing that one and not letting the others distract you. If it is a single fault, you will find it and fix all the faults.
This video is more likely to helpful.
He use a test light to send current down the ground wire for the inoperative sensor and finds the open ground wire.
Your codes sound more like the 5V reference is grounded.
Walta