[rmd1]

OK so I was driving along and pulled up to open a gate and left all my spotties on (2x7" hid, 2x9" hid, 22" light bar and 32" light bar) and the car stalled. I was playing around and realised with all my lights on it idles so low that it stalls. Runs fine when revving and also with the spotties off. Is there a remedy for this (besides turning the lights off) or will I just have to put up with it.

[Gwagensteve]

Alternator upgrade time.

[greavesyzook]

Are you scared of the dark?

[rmd1]

Any ideas on what alternators will work. I tried Google but can't find a definite answer and can't afford to play mix n match till I find something to work

[rmd1]

And yes I am afraid of the dark but I'm more afraid of Macropus rufus. And with how hard it is to find a bullbar I like as much forewarning as possible when Skippy decides to jump on the road

[Gwagensteve]

No, no idea.

you'll need to spend some time with a switched on auto elec, or choose an alternator with the rating you need and make bracketry to suit.

[sideways]

Bump up the idle speed a bit.

Wire it in so when you have you driving lights on the air con idle up engages.

No idea if those 2 are even possible on a H20 but anyway.

And yeah, you'l probably need an alternator upgrade to run all that. Measure your battery voltage with all the spotties on and a few revs (say 2000rpm), also measure it with them off and compare the numbers.

[30ONA]

Dual batteries?

[rmd1]

No dual batteries yet but would that solve the problem?
Also have had the car running for about half an hour with all the lights going and hasn't stalled yet. Could it be a sign of my alternator failing slowly?

[Gwagensteve]

No and no.

[vet 180]

I think an XL7 alternator should be a direct bolt in. They are 85amps and can be built to over 100amps. I assume you have the H20, not sure of the exact amps of your current alternator, but I do believe the H20, H25 and H27 all had different rated alternators from factory and even slightly different in physical size, but same mountings and electrical connections so the old alternators parts numbers could be superseded with the newer stuff.


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[rmd1]

Thanks I'll look into that asap

[Darrell]

Would I be right in thinking a bigger alternator will still put the same load on the engine and stall it in this high current situation ??

[Gwagensteve]

It's not an engine load problem. Even a large alternator at full load (idle rpm) is only consuming around 1kw of engine power. The engines IAC will compensate for the alternator load. The problem is volts are dropping too l low because the alternator is maxed out and you're discharging the battery. Modern ignition systems (and the fuel pump) need a solid 12v to operate.

[sideways]

Seriously, measure the battery voltage whilst you've got the spotties on.

[fordem]

Gwagensteve wrote:

The engines IAC will compensate for the alternator load.

Theoretically yes, in practice, I'm not so certain.

The IAC only does what the ECU tells it - the ECU selects a "target idle" rpm and then adjusts the IAC so that the engine maintains that rpm - but what if the engine cannot support the load at that rpm - it slows down and stalls. The ECU can and does change the target idle in anticipation of increased loads, typically these are - the power steering pump, the air conditioner compressor, the blower fan and the lights - but - and this is the important part - the ECU does not actually know if the load on the engine or the alternator has increased, it just knows that a switch has been closed, and because there is no "sense input" monitoring the spot light circuit, it doesn't know when the spot lights are on and can not compensate - it should sense the decrease in rpm, and should compensate for that, but if the load is excessive, it will slow down and stall.

Quote:

The problem is volts are dropping too low because the alternator is maxed out and you're discharging the battery. Modern ignition systems (and the fuel pump) need a solid 12v to operate.

Theoretically possible, but again I'm not so certain.

The battery serves two purposes, one is to allow the engine to be started, and the other is to supply electrical power for short periods if/when the demand exceeds the available output from the alternator - a situation that was once very common, back when cars had DC generators - but the exact situation that we are faced with here.

Now, no detail was provided on the current draw or wattage of the lights so we're going to need to make some assumptions - two pairs of HID lights, either 35 or 70w so 140~200w, a 22" and a 32" light bar, can we say, maybe 300w for a total of something approaching 500w, maybe 40~45A - a typical car battery is between 40~60 Ah, assuming a fully charged battery and the engine off, we can expect 30 minutes or more before that battery gets down to a 50% state of charge - with the engine running and the alternator providing some degree of charge, that time to discharge would be longer, and my guess is that battery would have to be pretty close to completely discharged for it not to be able to support those lights with the reduced alternator output at idle - so close that it would not have been able to crank the engine.

[atari4x4]

pretty sure tombut put an EL alt on his H20a

sirch.

[rmd1]

sideways wrote:

Seriously, measure the battery voltage whilst you've got the spotties on.

Been meaning to but someone stole my multimeter and every time I go to town I forget to buy one.

[rmd1]

Hid's are 100w each 22" bar is 200w and 32" bar is around 1400w. Unsure of amperage draw but they're all under 30 amps.
Also the battery didn't go flat as it cranked over strongly and started almost instantly

[atari4x4]

viewtopic.php?f=4&t=7157&p=338478&hilit=falcon#p338478

[Gwagensteve]

1400w? Are you serial?

[Gwagensteve]

Current draw is ~8A per 100W.

Let's assume your 32"bar is 400W not 1400w (116A)

You're drawing 64A, plus running the car and headlights.

You're discharging your battery regardless of revs when your lights are all on- you're drawing ~85A minimum and your alternator can't deliver that.

[rmd1]

It was advertised as around 1400w (not sure on exact number) but I can't confirm that all I know is its bright as hell. I removed it anyway to do some more welding on my roof cage and the 22 bar is set up as a work light on the back of the cage and only gets used for closing gates and working at the rear etc. I'm going to leave the 32" bar off for now and replacing the 7" hids with some 9" round led lights and see how I go

[fordem]

rmd1 wrote:

Hid's are 100w each 22" bar is 200w and 32" bar is around 1400w. Unsure of amperage draw but they're all under 30 amps.

All under 30A meaning, each one is under 30A or the total of them all is under 30A? 30A at 12V is 360W, your stated wattages total 2kW.

Quote:

Also the battery didn't go flat as it cranked over strongly and started almost instantly

Based on the fact that you didn't mention any difficulty in restarting after it stalled, I assumed this was the case - this simply reinforces my point that the problem is more likely to be the IAC not being able to compensate for the additional load.

As Steve has pointed out, you are going to need to upgrade the alternator, but I suspect may not resolve the stalling issue.

The idle control system on the H20a engines is quite primitive - the actual ECU/IAC system has a limited range so a two part system is used where the first part is a fast idle system that should only be functional when the engine is cold - this physically holds the throttle plate open, in a manner very similar to how it was done on a carbureted engine, and allows air to bypass the ECU/IAC system, when the engine is at operating temperature the fast idle should disengage, allowing the second part, the actual IAC system, to take control.

This fast idle part of the system is mechanical with no electronics - it uses wax warmed by the engine coolant to move the throttle stop and prevent the throttle plate from closing - as the coolant warms the wax it expands moving the stop and allowing the throttle plate to close more.

The IAC system itself has two air passages, one that is controlled by the IAC valve and a second which bypasses the IAC valve and has an adjustment screw - this screw is not an idle speed adjustment, even though it may appear to adjust the idle speed - it is used to set the IAC solenoid duty cycle.

The IAC valve is a moving solenoid type and when the system is correctly adjusted, the solenoid should be running at a 50% duty cycle (energized 50% of the time, de-energized the remaining 50%) - the adjustments for the fast idle and the IAC have some degree of interaction, if the fast idle is incorrectly set, the IAC will be affected, and it is possible to get the engine to idle properly without the IAC solenoid duty being correct, although if this happens, the IAC system may end up with an even more limited range of control.

You could literally have a situation where the IAC's limited range of control does not allow it to compensate for the additional load of the lights.

[rmd1]

30A each. Is there a way to check/repair/replace the iac

[Gwagensteve]

30A is 360 watts.
Your alternator likely produces around 60A when hot and over 3000rpm. (So ~700 watts) at idle you'll be lucky if it's doing 30A

The factory alternator is sized to run the car, not any accessories you've chosen to fit.

Whilst Fordem's tech is impeccable, I genuinely believe you're driving around with a deeply discharged battery and a maxed out alternator and that's causing the problem.

[fordem]

rmd1 wrote:

30A each.

I'm not buying that - a single 100W HID will draw 16A, a 200W LED bar will draw 32A, if it's actually 200W and that 1400W LED bar will draw 116A, if it's actually 1400W - you need to stop guessing, get around to buying a new meter and a DC clamp adapter and make some measurements.

Quote:

Is there a way to check/repair/replace the iac

Start the engine and drive the vehicle until the engine is up to operating temperature, so that the fast idle mechanism is, at least in theory, disengaged, stop the car, and whilst stationary attempt to turn the steering either left or right, watch the tachometer closely, as the power steering pump takes the load you should see the engine rpms drop slightly and then increase as the ECU/IAC compensates, you should also be able to hear and see the rpm change when the a/c is switched on, it should increase by 50~100 rpms.

Please note - if I am correct, you could have a fully functional IAC, and still have an issue because it does not have enough range to control the additional load.

[fordem]

Gwagensteve wrote:

30A is 360 watts.
Your alternator likely produces around 60A when hot and over 3000rpm. (So ~700 watts) at idle you'll be lucky if it's doing 30A

The factory alternator is sized to run the car, not any accessories you've chosen to fit.

Whilst Fordem's tech is impeccable, I genuinely believe you're driving around with a deeply discharged battery and a maxed out alternator and that's causing the problem.

Steve, whilst I agree with a lot of what you say here, the one "hiccup" is that deeply discharged battery - if the battery was deeply discharged he should have had trouble restarting the car when it stalled.

The factory alternator may be sized to run the car but it does have some "cushion" - I've run driving lights on almost every vehicle I've owned in the last four decades and never had an issue - I'm currently running 200W in halogen spots on my 98 2.0 GV (70A alternator), no issues with the idle (this engine uses a stepper motor IAC that can run the engine as high as 1800 rpm), and no issues with deep discharge of the battery.