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Discussion Starter #1
Not a huge issue but something I could use fixed if possible.

I have a 96 4.6L parts car, it was running fine up until about yesterday. It sits and doesn't get started much but I do start it just to keep it working kind of thing.

Yesterday I was over checking it out and wanted to test an SATC I got from the wreckers, so I plugged it in and it turned on, but wouldn't select anything, so I figured no vacuum and tried to start the car.....battery is dead.

Pull out the jumper cables and start the car. SATC seems to work fine, I shut the car off and do a little work removing the shifter knob.

jump the car and start it again, now the SATC is acting funny. it flashed on, then turn off, and wouldn't do anything. no controls responding on it, and the display wasn't on.

now the car dies again, jump it again and it would run for a little bit then die when I remove the jumper cables. I used a clothes pin and kept it revved up above idle, and it would run for a little bit longer, then start to rumble and die out running poorly.
this would happen anywhere from 10 secs. to 1 min after removing the jumper cables, with the engine at a higher idle....maybe 1500rpm - 2000rpm (there are no gauges in the car)

Checking with a voltmeter shows the alternator not charging now (I can only guess it was charging before because i KNOW it worked before I removed the gauges) the battery is dead, and running at high rev i can only measure 11.58V at the battery..... of course I don't get much time before the darn thing dies after I remove the jumper cables so I had to measure voltage with the cables on....should be the same if it was charging, I should still have seen 13.95V.


so aside from the battery being dead, does anyone have any ideas as to why the car won't idle? Heres what I know.

No gauges, I took those out.
Airbag module was unplugged yesterday, the beeping was annoying.
No radio, SATC, infocenter, door panels/switches/shifter. all removed
AFAIK it was working/charging before I tried out that SATC.
Battery is dead, and alt doesn't seem to be charging, but was charging before the SATC(don't if it's (fuse) related, just posting what I did)
IAC valve is shot, sounds like a fog horn, but didn't cause the car to stop running before.
cats are clogged a bit, smells like crap, and it's been running rich and dirty since it sits a lot and doesn't get driven.
 

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I have been having alot of battery problems lately, Thats where I'd start. Instead of checking voltage at the battery check it at the alternator that way a bad battery wont give innacurate readings,you could also do it while its hoked up to the jump vehicle. Also most auto parts store's in my area test and charge battery's if you dont have your own load tester. Hope this helps!
 

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Discussion Starter #3
I checked the alternator today by measuring against the postive pole on the alt, and the alt case..... it was somewhere around 8V IIRC

Battery sits around 11.5V until the car is running and then drains slowly until the car dies.


fairly sure it's the alternator at this point, but what I can't figure out is why it just stopped working.a buddy of mind thinks that after sitting for a while like it has been, and revving it up high like I was a couple weeks ago when I started it last, has killed the alt..... I gotta say I don't really believe that. The engine was hot, and I got her up to 4000 or so revving to try and burn a bit of stuff out of it, but it wasn't held at that RPM.

is it possible removal of the gauges has somehow affected it's charging abilities? This worked fine before, and there seems to be no reason for it to have just stopped working.
 

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i second vicrattlehead if there is no cluster in the vehicle and the alt light cant come on to do the self check the car will not run or charge. im willing to bet 100% that is your issue.
 

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Discussion Starter #6
well that makes sense, didn't know it was related.

can't put the cluster back in yet, it would need to be soldered back in as I cut the harness to put into my 97 and haven't done that yet due to snow....and a bit of laziness.

Could i just jump that wire?? like with a lightbulb or something, just to make it work?
 

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You can just put a idiot light (Maybe a 194 Bulb?) of some kind between the Light Green W/ Red? wire at the alternator and Ignition's plus wire (Reg w/ Green?) and it SHOULD start the charging Cycle.. In reality, Once the Alternator starts to charge, that circuit really isn't needed anymore..
 

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Discussion Starter #8 (Edited)
ya thats right, it needs to send 12v to the (stator?? can't remember off hand now) to get it going.

so LG/R is a ground? I'll have to look at the wiring diagram, but not sure which one I'm looking for. the cluster??







Looking at the diagrams, it would appear I need a 500ohm resistor as well as the bulb, my guess would be that it's needed in case the bulb burns out, so it will still complete the circuit and start charging.
 

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Well i don't think te 10 Ohms is going to be the end of the world... Also i think the resistor does all the work.. the bulb is just for show :)

aslong as you hook one end to switched power and the other to the Light Green With Red you should be okay..
 

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Discussion Starter #11
the resistance in general i think is what does it. I would gather the bulb has less resistance than the resistor or it wouldn't light up (path of least resistance) if the bulb went out and the wires were jumped there would be no resistance. Obviously for whatever reason resistance is important.

I'm just throwing a guess out there, but I think it has to do with charging voltage. Ive various "voltage enhancements" some of which just being adding a resistor somewhere on the alt. Anyway that aside My DD charges at 13.95V, since I'm using a 510Ohm resistor on my parts car, it's charging higher, 14.7V .... It may also be that the alt on my DD didn't kick into charge when I tested it, this is the most likely cause.
 

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Technically anything above 12.2 Volts is charging..

Also an alternator will lessen the output voltage as the demand for charging the battery lessens too..
 

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Discussion Starter #13
Ya, I think it was a matter of my DD being charged, and not needing much, and my parts car being darn near dead and needing a good charge.

I just know there are ways to get them to charge higher, like 15V+ in some car audio situations. sometimes it's a simple mod, sometimes it's an expensive device and other equipment.

Anyway, for my purposes, it's keeping my battery charged :D
 

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I think the wire that loops back from the 3 pin connector at the alternator to a single Connector is the one that controls the voltage?? I could be wrong.. i have to look this up again... That and i don't know if the 130amp alternator on the 4.6L has this? i know the 130amp 3G i put onto my '91 XR7 did..
 

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Discussion Starter #15
yes I believe it has one, and I think it does work the same way. You put more voltage into the rotor to start and it will charge higher. it only needs the inital boost to get the field going, then it will charge without voltage being applied to the rotor.
 
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