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Discussion Starter #1 (Edited)
***SOLVED*** 9/13/2016
I just had my AC repaired by a local mechanic and now I find I have low voltage at my accessory plug inside when the engine isn't running but key turned on. Electrical was fine prior and has never been worked on or had a problem.

Scenario A: Not running, Key on, about 7 amps being returned through negative battery lead.
1) Battery voltage at battery terminals is 12.7V
2) Voltage in cigarette lighter is 10V

Scenario B: Engine running (engine cranks but starting seems unenthusiastic)
1)Battery voltage 13.6V
2)Voltage in cigarette lighter is 14.2V

I first noticed a problem when I was in city traffic at night and upon braking my headlights would dim intermittently.
Next day I noticed the engine would stumble each time my intermittent wipers kicked on.

I am assuming the mechanic didn't get a wire on the alternator correctly when he replaced the AC compressor (or he damaged something).

I cant find a wiring diagram showing what wires are supposed to be hooked to what terminals (and I cant see down there very well anyway without removing stuff).

Does anyone have a picture of what wires hook where on the back of my alternator?

Appreciate any help.

(Also, the AC works like crap now..I'm taking it back to them Monday but I think I can diagnose better than these guys at this point).
 

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2011 Forte SX 2.4L (thankfully MPI) A/T 137K miles
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Although I'm not familiar with your vehicle, what you describe sounds like a generic battery connector or wire problem. Either a battery connector is not tight enough, or a portion of the wire has degraded, which can happen when corrosion eats away at it over time. And, if there is corrosion present, the mechanic's work could have altered the alignment of the wire just enough to cause what you're seeing now. Check that the connectors are tight and also gently move the battery wires around a bit, to see if there's any change in those voltages.
 

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Discussion Starter #3
I agree and I did take a look at everything that was easily accessible. Wires are all clean and the junction taps at the battery positive all look good. The connections at the back of the alternator are hard to see without taking apart some of the junk on top of the engine. Calculations would imply about a 1/3ohm drop between the alternator and the battery (corresponding to the 2 volts lost when 7 amps are being supplied bye the battery.

My real question is where is the tap for power to the car electronics made? In the 70's the tap was made at the starter terminal positive. I have no idea where the physical connection is made on my Borrego and that is important to know.


I have the car back at the shop who did the work. They were full of reasons why it couldn't have been them OR why the cigarette lighter at 10 volts was to be expected. hell, I think the computer and all the stuff running with key in the on position is having a hard time working at 10V.

If they dont fix it I'll probably be forced to dig into it myself to find where the 1/3ohm resistance is being introduced. I just wish I could see the back of the alternator without taking stuff off the car.


Although I'm not familiar with your vehicle, what you describe sounds like a generic battery connector or wire problem. Either a battery connector is not tight enough, or a portion of the wire has degraded, which can happen when corrosion eats away at it over time. And, if there is corrosion present, the mechanic's work could have altered the alignment of the wire just enough to cause what you're seeing now. Check that the connectors are tight and also gently move the battery wires around a bit, to see if there's any change in those voltages.
 

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2008 SpectraSX, 2014 Optima LX,2006 Jeep Liberty, Linux Mint Mate
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Looking at what you said...

"
(1) Scenario A: Not running, Key on, about 7 amps being returned through negative battery lead.
1) Battery voltage at battery terminals is 12.7V
2) Voltage in cigarette lighter is 10V

(2) Scenario B: Engine running (engine cranks but starting seems unenthusiastic)
1)Battery voltage 13.6V
2)Voltage in cigarette lighter is 14.2V

(3)I first noticed a problem when I was in city traffic at night and upon braking my headlights would dim intermittently.
Next day I noticed the engine would stumble each time my intermittent wipers kicked on.

#1 There is a 2.7 volt drop in the wiring from the battery going to the lighter outlet with the engine off (alternator not charging)
so the current is coming from only the battery

#2 "engine cranks but starting seems unenthusiastic"
again...current is only supplied by the battery and there is a voltage drop feeding the starter motor...
Once started the voltage at the lighter is HIGHER that at the battery...
That says that the alternator is not properly charging the battery through the wiring ...BUT... IS supplying enough current to the lighter outlet (good wiring there)

From that I would deduce that the wiring from the battery is at fault.... Probably the ground wire from the battery to the body/frame/chassis is at fault...
Why??? Because the alternator has a separate ground to the body and it doesn't rely on the ground from the battery to supply the return current....
The positive feed from the alternator and the battery positive feed connect to the same spot on the fuse panel under the hood so is unlikely where the "problem" is...


Just my analysis from the information supplied...
Dave
 

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Discussion Starter #6 (Edited)
Thanks for everyone's help....I've included a drawing of what I think has been said so far. Please look at it and let me know if there are any problems with it. Specifically where the connections are made..junctions and taps. I know on old cars the power to the car chassis was tapped at the starter. Since I have what appears to be a BUS off the positive terminal with fusible links of the bus (150 amp) I think manufacturers have rethought connections on cars since the 70's and 80's. So bad connection where indicated? Does my drawing look correct?
 

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Discussion Starter #7 (Edited)
Update. AC has been fixed and was not the cause of the low voltage. Freon leak had it down to about half charge they said.
Electrical problem. Turns out the battery ground to chassis is just in one place so this is the return for the starter as well. (see pictures showing negative terminal and negative attachment to body, positive terminal and drivers dash fuse block).

I was still getting the low voltage at the assy outlet in the dash (10V). Pulled and replaced the shunt (item 14 in the fuse diagram) and the voltage immediately went to 12.3 volts (same as battery). However, strangely this voltage then seemed to fluctuate as if there was something regulating it. So do do not think the SHUNT jumper was the problem...I think it reset something that then controlled power supplied into the vehicle. I have no schematic and I'm only guessing. As of now I will ignore this as an issue.

I would like to request others with Borregos to check their cigarette lighter voltage with the key on but not running and tell me what voltages they see and if it remains steady after cycling engine running to not. Also, if convenient, other KIA owners might check this voltage also and report it here in this thread to me just to see if KIA systems across models are consistent. Thanks for everyones help in this.
 

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Discussion Starter #8
Update

The voltage drop continues to get worse and is forcing my hand. Radio is now shutting down for a second during these power excursion that occur while driving and flipping on headlights and such. This may be a combination alternator grounding issue.

Tonight I found that feeding the fuse distribution box under the hood main wire shows 10 volts from "Box input POS terminal" to engine block. However, from the "Box input POS terminal" to the negative terminal it shows full battery voltage so this is a grounding issue.

There are numerous ground lines connecting battery negative to body then body to engine block, opposite side of body to fender and also to frame rail.

All of these look clean rust free and undamaged so I am perplexed.
Due to cramped engine bay it is difficult to get to these ground bonding points. I dont live in a particularly salty winter environment (southern indiana) so I wonder why this is happening and if anyone else has experienced ground bonding issues on Kia vehicles?

Anyway, worst case I start running new grounding wires until I get a clean return.

I wish I had a good drawing showing physical attachments points for the grounding cables and a logical current flow diagram.
 

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Discussion Starter #9
Update: DavesSPECTRA You surmised correctly. The problem was the MAIN Ground attachment from the battery to the Frame/body. This main and sole Ground wire from the negative terminal attached down by the headlight to the body of the vehicle by two bolts clamping the bonding cable end directly to the painted inner engine compartment. The bolts that came out were corroded pretty well from whatever is under what they bolt to. I cleaned up the contact surface of this cable end and also removed the paint from the bonding surface. Replaced one bolt that didn't have enough thread left to torque the bolt in properly. There are many more "ground bonds" to the chassis using the same method that I have not addressed. They will be my first suspect if problems appear in the future.

I was able to determine with certainty it was a ground issue when I found the input to the engine compartment fuse box. At this main HOT feed point I was able to see reduced voltage when current was being drawn when referenced to the engine block. When I changed the reference to the battery terminal it was the full 12.5 volts.

Thanks for your help and analysis.
 
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