Thread: Elusive Electrical Problems

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  1. #1 Elusive Electrical Problems 
    SE Level Member Wakingcrow's Avatar
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    I posted pics mostly of OBD readings and a video of engine attempting to run normally.

    Microsoft services

    Information:
    1. Per the upstream O2 sensor: it wouldn't come out and the wires severed at the tip so I disconnected it. I tried connecting another one and covering it, but it doesn’t change anything. At some point I'll replace the header/sensor but I doubt that's the source of all this erratic behavior. It should be running open loop without the O2 according to my research.
    2. Cooling fan errors can be ignored: I jumped the relay to switch them on when I see fit because otherwise they don't come on til 225 or whatever it is which is too hot.
    3. Replaced VSS (502 error) with a junkyard part but nothing changed at all.
    4. I looked all over the wiring harness for exposed wires and shorts, only place I found that was by the PCM and some of them looked like they had been eaten by a rodent. I repaired and shielded them but the only result was the speedometer came back online.
    5. The TAC 2107 and solenoid 1860 errors I thought would resolve by fixing problems with the wiring harness but car still running poorly, as said nothing much changed.
    6. Low beam relay was clicking every time battery died, and still did that after I swapped the 8866 relay. Low beam headlights keep going out very quickly. I get them from the junkyard but they burn out about once a month. I don’t see a wiring problem visible there either.
    7. Battery normally checks at 12.6 when not dead, and 14.6 while car running. I tried to drain test by bridging connectors with terminal on amp several times and each time there's miraculously 0 load, even when I open a door or turn on the key. I also pinned the meter on both sides of each fuse and none had load with car off. All of which seems impossible, since the battery drains and usually doesn’t start without boost, even minutes after running for a while.
    8. It's a 2004 Grand Prix with 195k miles and I'm the only mechanic I can afford. I can’t afford a new car either. This is it.

    Problems still existing:
    Engine RPM fluctuating drastically, except when idling after a minute of warmup (tac?)
    Sputters on acceleration without delivering much power (tac?)
    Hard time starting especially when battery mysteriously drains (solenoid?)
    Battery keeps getting drained or shorted. (no idea anymore)
    .
    Anything you know that will help is appreciated.
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  2. #2 Re: Elusive Electrical Problems 
    Turbo is the way to go. BillBoost37's Avatar
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    Rodent/broken wires issue - In my eyes this is the first area you should make 100%. I'm not a fan of butt connectors because they don't always give the best connection and yet you'll see these on boats and other vehicles that never have an issue. Test for continuity in those wires to ensure that your fix has fixed the issue. Also write down the pin/connector numbers for those wires and look them up to see if those are related to your TCC/TAC/VSS. My thought is something in those wires is related to your other issues.

    Now.. if all those wires are good and you don't find other problems.......then I'd look below:
    TAC - Throttle Actuator Control - This is the throttle control aka if your rpm are fluctuating I'd understand. Do a search on this site for the code/TAC issue, I remember reading up on how people have fixed this problem.
    O2 not coming out of the bung - Have a muffler shop weld a new bung in place and that problem is fixed. An O2 for upstream can be put into the crossover pipe if needed.
    Cooling fans - consider it ignored. FWIW, not sure why you'd mention it and post a picture of the code while saying ignore it.
    VSS - When you replaced the sensor did you wipe the goop that accumulates on them off? Check the connector to ensure the pins are in place and not pushed out. Ensure the wiring looks good and is not rubbed on the axle or anything silly. If you pulled the rear manifold off, you may have bumped/rubbed/pinched the wiring.
    Battery issue/miraculous 0 load - Look at your battery, do the sides seem bowed outward/puffy and is your battery over 3 years old? That would point to a bad battery. If you charge up the battery to 100% and can leave one of the cables unhooked for say two days then hook up and have good power, your battery is good. Obviously that would be you need to find a short. Coming back to the 0 load when opening a door etc (as long as battery had power), it sounds like you performed the test incorrectly or on the wrong meter reading/scale. There has to be a small change in load if you open a door etc.

    For your symptoms and issues, I'd really concentrate on the wiring and ensure the battery is good. If you have questions on how to use/test with a multimeter there are some very good vids on youtube or ask here and we could link you to a good video/explanation.
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  3. #3 Re: Elusive Electrical Problems 
    GTX Level Member QUICKSILVER462's Avatar
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    If you have found ANY wires that have been, or looked like they have been eaten by a rodent,... chances are there are more wires the with the same problem, you just have not found them yet.

    I have not had rodent problem eating wires on my car, but I have had chaffed wires cause problems. Solution: disconnect PCM and check continuity on every pin from the PCM connectors to each individual wire destination, be it sensor, relay, bulb, ect. You may be able to narrow it down by subsystem following a wiring schematic, that is what I did. It's the only way to be sure you dont have a broken, or partially broken wire/wires somewhere. You have to be absolutely certain there are no breaks in the wires before you can continue diagnosing.
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  4. #4 Re: Elusive Electrical Problems 
    SE Level Member Wakingcrow's Avatar
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    For the record, I have no idea how a rodent would get into the air filter assembly and then feel the need to start chewing wires to get out a different way then it came in, but it might have been holding on to them for dear life and then got sucked into the throttle and into the engine and that would explain why suddenly it has so many problems. I pulled the throttle body and it looked fine visually, good action.
    The battery is about 6 months old and is the 3rd replacement on a Walmart 2 year battery warranty and I think it's still good as it tested a month ago to be fine, unless recent stuff killed it.
    I just posted all the errors from OBD, including the P480 which was apparently the only thing I could get freeze frame data on, no matter how many buttons pressed on the scanner.
    I like the idea of putting the sensor in the cross pipe but right now I need to solve these massive electrical problems.
    Right after I posted this I saw other posts suggested and people said similar problems were ignition switch. Does anyone suppose that the ig switch or other items could have been injured by the shredded and crossed wires shorting things out? Even if the wires are perhaps fixed now.
    Also does anyone think it's possible that a car can have a hex put on it? Because it was fine for 15 years but the past year at least 300 things have gone wrong.
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  5. #5 Re: Elusive Electrical Problems 
    Killa Bee Scottydoggs's Avatar
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    you do have a 3 inch intake hole in the fender well of the air box, mice love a nice dark box to nest in. the mice would be under the air filter where the pcm is unless they ate through the air filter. in the end, they love to chew wires for some reason lol

    98 Buick Regal GS, F body brakes, Caddy STS wheels, tinted tails L36 bottom end, lightly ported heads, 1.95 roller rockers, headers, gen 5 N* 3.0 pulley, FSIC, 42 lb injectors, a BrandonHall rebuilt trans, DHP tuned and AEM water/Meth injection https://goo.gl/gpV5kW
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  6. #6 Re: Elusive Electrical Problems 
    Turbo is the way to go. BillBoost37's Avatar
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    Having seen the pictures of the wiring and the "fix", I'm still on the wiring issue thought. Always go for the obvious things before you spend extra money and time on something that hasn't shown you any signs of being an issue.
    I drink..so consider that when reading my posts.

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  7. #7 Re: Elusive Electrical Problems 
    SE Level Member Wakingcrow's Avatar
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    So you guys are saying I need to plant the mousetrap first then go from there?
    I'm pretty sure the offending mouse got sucked into the throttle and became fuel.
    But seriously if there's a good way to test the ignition switch, tac, or solenoid I'd be happy to do that before investing more.
    I did the standard load test with two different meters and they both had zero. Just bridging the neg terminal with the connector not rocket science. No amps appeared under any circumstance which I think is impossible and thus somebody put a curse on the car.
    I heard if I get the head of a live rooster the curse can be removed. Any truth to that?
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  8. #8 Re: Elusive Electrical Problems 
    Turbo is the way to go. BillBoost37's Avatar
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    Let's clarify this further as you seem to be confused.

    1. The wires are on one side of the air filter and the throttle body is on the other. Unless you have a hole chewed in your air filter your theory about your car ingesting a mouse has been proven wrong by logic.
    2. Your fix to those wires is substandard, to do it properly you'd need a different harness or to solder/heat shrink and maybe replace a few pins in the connector if the wiring isn't long enough to do a proper fix.
    Here's a super easy soldering connection, only a heat gun required Heat Shrink Self-Solder Butt Splice Connectors - YouTube
    Here's how I would do it. How to Solder Wires Together (Best tips and tricks) - YouTube
    3. You appear to be doing something wrong on testing for load. Either you are using the wrong setting/scale or something else is going wrong with how you are doing the test. You should watch this How To Perform a Parasitic Draw Test - EricTheCarGuy - YouTube
    4. Testing TAC/VSS/Ignition switch: (sarcastic tone) Go right ahead and just replace all these items three times in a row because as you said you have no extra money and maybe they are all the problem and the wiring isn't the issue. I say three times because then you will have wasted a bunch of money and maybe you'll be open to listening to reason/experience. Occam's razor states: The simplest answer is often the correct answer.

    To be 100% clear, my suggestion is to follow the advice we gave you on fixing wiring/testing continuity and move forward from there. Meaning that you do the nearly free stuff and testing to determine the cause of the issues.
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  9. #9 Re: Elusive Electrical Problems 
    SE Level Member Wakingcrow's Avatar
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    The first thing I suspected with multiple sensor problems was wiring, so I checked it and saw nothing until I pulled the air filter and saw severed wires. Even before that I wanted to replace the entire harness but a few dollars short. And I replaced the speed sensor because it was easy and didn't cost anything.
    So my meter had a blown amp fuse and I fixed it. Able to do drain test. I posted pics in the same link above, but get this.
    Soon as I hook it up, it reads. 0.85 amps for about 15 seconds then goes less than 0.05. So I pulled fuses during each 0.85 interval and then disconnect and reconnect and pulled more. One fuse made it immediately go down to normal. The battery main fuse 1. I pulled it several times and watch the amp drop then go back to 0.85 after plugged back in. Doors opening did not change the load, but...
    Another thing I've noticed is the battery dies if a door is open for more than five seconds... Which makes no sense since I pulled the interior light fuse a month ago and they don't come on at all.
    For example, today I charged battery, drove five minutes to gas station, returned in ten and it started right up. Drove back and opened a couple doors to unload cargo and it was already dying with the clicking not enough amp sound trying to start it.
    I can't make heads or tails of it. There is a pattern to the behavior but not one that I recognize.
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  10. #10 Re: Elusive Electrical Problems 
    Turbo is the way to go. BillBoost37's Avatar
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    Where do you live? It doesn't make sense that you are burning through batteries as fast as you mention and that they die in 5 minutes. Literally you can leave a car's headlights on with the engine not running for longer than that and still have more power.

    Have you checked your battery cables for corrosion?

    The door thing makes me wonder as well, do you have any windows or power locks that don't work?
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  11. #11 Re: Elusive Electrical Problems 
    SE Level Member Wakingcrow's Avatar
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    It's well known in my car that continued arming and disarming of the anti lock theft system eventually kills the battery and combined with usage of anything like windows or radio or inverter with the car not running, usually kills the battery within a year. This being the last battery in the warranty replacement, I haven't been doing any of those things except using the auto locks. No corrosion, everything is clean and tight. After charging the battery today, I put on the volt meter and saw that it took only a few times using auto locks on and off for the meter to go down below 10v.
    Good news is I fixed the wild rpm fluctuation issue, as it was what I thought it was initially, the tube that runs from the front of super charger around rear to a wiring socket behind it. Because I had broken it on the side a couple years back, and it did the same thing. This time it was disconnected at that rear socket where I couldn't see that it was hiding right beneath it without actually being connected. But I was inspecting the wiring again and saw it was out of socket. Now my rpm and mpg are back to normal.
    Anyone know what those two wiring sockets are in the rear with the SC tube running to one of them, and what the tube is? I have included a picture, but that being disconnects causes wild RPM and bad MPG alone.
    Bad news is auto shops aren't loaning the OBD tool anymore so I don't know how they are figuring out what's wrong with anything, so I have to drive across town to borrow my brother's, read and delete codes, and drive cycle again. Car still misfiring and sputtering on acceleration but cruises fine for now.
    Meantime I'm trying to find some wiring diagrams and will go thru entire PCM pins or attempt to. I don't even know how to do it but I'm sure somebody does.
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  12. #12 Re: Elusive Electrical Problems 
    Turbo is the way to go. BillBoost37's Avatar
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    I have the ability to help you test that stuff. I do notice that you and I are speaking two different languages though. Oddly I've always been able to translate what people are saying into what is actually happening. Meaning..I can usually understand laymans terms into mechanic terms. For example your socket mention is talking about the map sensors mounted on a bracket on the back of the SC.
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  13. #13 Re: Elusive Electrical Problems 
    SE Level Member Wakingcrow's Avatar
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    That's why it takes me so long to describe it. Why does one map sensor work fine alone but the other freaks out without its air tube attached? Is it asthmatic?
    I think there's some hope here but I was wrong thinking all problems were related since they started at once. Instead, a hundred different problems all started this year.
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  14. #14 Re: Elusive Electrical Problems 
    Killa Bee Scottydoggs's Avatar
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    if you have a 04 up gtp you have two sensors next to each other, look the same, are the same, only one is a baro, the other is a map, the baro gets no vac line. left to open air.

    if you were to look real close at both nipples, ones gonna be cleaner where the vac line was all its life, the other the same amount of dirty on the whole nipple.

    98 Buick Regal GS, F body brakes, Caddy STS wheels, tinted tails L36 bottom end, lightly ported heads, 1.95 roller rockers, headers, gen 5 N* 3.0 pulley, FSIC, 42 lb injectors, a BrandonHall rebuilt trans, DHP tuned and AEM water/Meth injection https://goo.gl/gpV5kW
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