12V power outlet mod, possible?

[SSSVX]

See, some of the cars we drive. The 12V power outlet always stay on even if you turn off your engine, you can still charge your cellphone and get power from the outlet.

Some others car do not. Such as our SVXi don't have this feature. You have to turn your key to the ignition on in order to get power from it.

So how hard is it possible to modify our 12v power outlets(cigar lighter) to behave like the other cars at being safe?

[svxfiles]

It's as simple as running one wire.;)

[Trevor]

It's as simple as running one wire.;)

However, male sure you tap into a fused circuit. Otherwise add an inline fuse assembly close to the battery, if this is the direct source of supply. ;)

[SSSVX]

Hi, OT :D Thanks, Trevor. :)


However, does the factory one have the safety feature to automatically
cut off the power from the outlet if the system knows the battery is getting
too weak for you to start your car?

Say if you leave your car there for two weeks. And, you leave your power
outlet constantly on. If your battery is not strong already, weather's cold,
would "that" make your battery dead or too weak to start later on?

[svxfiles]

Hi, OT :D Thanks, Trevor. :)


However, does the factory one have the safety feature to automatically
cut off the power from the outlet if the system knows the battery is getting
too weak for you to start your car?

Say if you leave your car there for two weeks. And, you leave your power
outlet constantly on. If your battery is not strong already, weather's cold,
would "that" make your battery dead or too weak to start later on?

Unless you have a device plugged into the "hot" outet, then it would be no different than with a stock setup.
(Where the clock is the biggest drain.)

[longassname]

I'm going to be posting more on this in the alternator wiring mod thread after I get someone to verify some stock wiring for me and I verify my own earlier observations..but it effects the idea of leaving things plugged in so I'll mention it here and now--not that it's a huge deal as it pertains to this or anything....but

Our alternator appears to function like a one wire alternator. If the S terminal isn't connected the alternator will still produce voltage and is still voltage regulated. The alternator currently on my car drains 210mA anytime there is power applied to the S terminal--as I believe in the factory wiring (this is what I'm waiting for verification of) the s terminal is connected to battery rather than ignition like most cars I think this drain is a malfunction in my alternator. Anyway, while I had the ammeter hooked up to find the drain and was pulling fuses I noticed my 210mA drain would go up to over half an amp after anything was powered back up and then 7 or 8 seconds later go back to 210mA. I took this to be the alternator kicking in the field current everytime anything drew any power from the battery.

If it does turn out that the s terminal is connected to battery with the stock wiring I'm going to be suggesting that people modify their wiring to put their S terminals to ignition. The AC fuse in the corner of the engine bay fuse box is a convenient source of ignition switched power. I have a fuse tap there and am now using it for both my alternator s terminal and my transmission cooler thermostatic switch.

[Trevor]

Anyway, while I had the ammeter hooked up to find the drain and was pulling fuses I noticed my 210mA drain would go up to over half an amp after anything was powered back up and then 7 or 8 seconds later go back to 210mA.

By "after anything was powered back up". Do you mean "After a load was applied, when previously there had been no load connected"?
But then if so the applied load would surely remain and be indicated. :confused:

Please again explain in detail this rather strange occurrence.

[longassname]

Some of the fused circuits have things that do something when you connect them and some have capacitance banks on them so plugging the fuse in created a momentary draw that was enough to trigger something else into drawing a half amp for a short time (I didn't isolate the alternator at the time to verify that is for sure the alternator--I was connected between the battery and fuse box). Applying an ongoing load like a light would do the same thing but I would see the additional half amp on top of the ongoing load--then the additional half amp would turn off 7 or 8 seconds later, I didn't count the exact time.

I'm just guessing it's the alternator field current since the fsm states that the alternator does generate voltage and is voltage regulated without the S terminal connected...to me that means it's a single wire alternator with an extra, somewhat optional voltage regulator input.

By "after anything was powered back up". Do you mean "After a load was applied, when previously there had been no load connected"?
But then if so the applied load would surely remain and be indicated. :confused:

Please again explain in detail this rather strange occurrence.

[longassname]

I also unplugged the S terminal and verified that it does in fact generate voltage without it.

[Trevor]

Thanks Michael.

I have always assumed that the alternator was set up to charge without the regulator, more or less as a fail safe arrangement with the energising circuit being n/c, but who knows?

I am presuming the 210 mA drain is via the main charging circuit rather than the voltage sensing circuit.

My first thoughts were to suspect that you may have a diode reverse leaking in your rectifier bank, however the fact that the drain only occurs when the sensing circuit is complete, rules this out. I presume that the measurement was made with the ignition switch in the off position, thus ruling out the charge warning lamp.

My car is away at the moment, but when it is available I will check for standing current along with your experience. At this point it must be established that what you have discovered is common to all cars, rather than a possible regulator IC fault, only applicable to yours.

There is still a hazy view on this whole set up, as nothing appears to conform with the wiring diagrams and as yet, no one has confirmed the connection of the two white wires running from the main charging terminal on the US cars. However I gather you do not have these in place.

Another curly one! :eek:

Nga mihi nui, Trevor

[longassname]

If I remember correctly the white wires were joined and the wire from the S terminal was joined with them. It's been years though so I asked someone else to check theirs. I haven't heard back from them yet.

The power distribution schematic in the fsm shows the 3 wires joined. The alternator schematic shows the s terminal wire connected to the ignition switch like it is in most cars.

Yes the 210mA drain is through the charging circuit not the regulator, disconnecting the S terminal does turn off the drain, and measurements were taken with the ignition off.

[Trevor]

Thanks again Michael for the quick reply.

The power supply routing wiring diagram in the US electrical section of the service manual which I have, as you say shows the three wires joined together. It is a wiring diagram rather than a schematic, so should show the actual connection points, but it does not, and here stems the difficulty in sorting things out. The evidence to date indicates that the diagram can not be accepted as truly representing the actual connections. But damn it let us leave that aside in respect of the current topic. ;)

To operate exactly the alternator sensing supply should be sourced direct from the battery. The use of any point within the distribution network, results in inaccuracy, due to line resistance and connected load. If that is a situation other manufacturers accept so be it, and it would confirm the general ineptitude, there being no reason why this circuit should draw inappropriate current.

I will have to have fun checking my car before getting back to you. Meantime the plot thickens. :)

[SSSVX]

Unless you have a device plugged into the "hot" outet, then it would be no different than with a stock setup.
(Where the clock is the biggest drain.)

OT, what do you mean by "hot" outlet? Don't understand too much.
You're saying it won't drain the battery power too much, as it's about
same as the clock?
What is the max A you can get from that power outlet?
How much A does the clock draw from the battery?

Compare to if you leave your "parking light" on, the "parking light"
is drawing a lot of more power, right? I wonder how many hours
it will last till the battery dead if you leave it on all nights.

I don't know if any related to what they discuss. My teal one's
rear wiper blade will draw my full battery in 4-5 hours. During winter,
snow and icy, I turned on my rear wiper but it was stuck. I was
in hurry and I left it on and got off the car. I know my battery was
in good conditions. When I came back, I needed a jump start as
I couldn't start my SVX because the rear wiper didn't go back
to its original position and it kept trying until the battery's dead.

[longassname]

A lot of oe alternators don't try to sense if the car is being started and thus that the field needs to be energized. The field (s terminal on most japanese alternators) is simply given ignition switched power--simpler and more reliable.

I'd rather be overcharged than undercharged. I've never seen one of these alternators come anywhere close to overcharging and I've seen a good handful of them undercharging. While almost all of this has to be blamed on poor quality aftermarket rebuilds it also seems safe to say the oe voltage regulators are tuned a little on the low side. I think connecting the S terminal to an ignition switched circuit asside from protecting the battery from run down when the alternator develops the fault I have currently (and have seen before) and regulating voltage off of a circuit with more resistance will tune it to charge a little more while still being safely on the safe side.

I do not have a wire going directly from my alternator to my battery. I replaced the interlaced white wires going to the fuse box with a pair of 8 gauge 100% tinned cables. My battery power is only connected by the oe 10 gauge wire going to the fuse box to the fusible link. Even so i show virtually no voltage drop with every accessory going.


Thanks again Michael for the quick reply.

The power supply routing wiring diagram in the US electrical section of the service manual which I have, as you say shows the three wires joined together. It is a wiring diagram rather than a schematic, so should show the actual connection points, but it does not, and here stems the difficulty in sorting things out. The evidence to date indicates that the diagram can not be accepted as truly representing the actual connections. But damn it let us leave that aside in respect of the current topic. ;)

To operate exactly the alternator sensing supply should be sourced direct from the battery. The use of any point within the distribution network, results in inaccuracy, due to line resistance and connected load. If that is a situation other manufacturers accept so be it, and it would confirm the general ineptitude, there being no reason why this circuit should draw inappropriate current.

I will have to have fun checking my car before getting back to you. Meantime the plot thickens. :)

[Trevor]

I replaced the interlaced white wires going to the fuse box with a pair of 8 gauge 100% tinned cables. My battery power is only connected by the oe 10 gauge wire going to the fuse box to the fusible link. Even so i show virtually no voltage drop with every accessory going.

I guess that the 100% tin makes a difference. :rolleyes:
Joking aside, as you have replaced the two white wires, could you please advise as to where they were connected within the fuse box. This is information of special interest.

[longassname]

in the long run the 100% tinned makes a difference..I like to do things once..once


I'm pretty sure one was connected to the fusible link and the other to a slow blow fuse..both in the fuse box in the engine bay. I believe the whole thing is only held in by that one bolt and can be easiliy pulled out to look at the wiring.

[Trevor]

in the long run the 100% tinned makes a difference..I like to do things once..once


I'm pretty sure one was connected to the fusible link and the other to a slow blow fuse..both in the fuse box in the engine bay. I believe the whole thing is only held in by that one bolt and can be easiliy pulled out to look at the wiring.

That was quick, :) Thanks.

The tinning does what it is intended for and makes soldering easier that's for sure.

It would appear that the connections are the way they are, because the fuse box is a standard universal design. Even so running two wires, when a link at the fuse box and a single wire would suffice is strange, but typical.