Divert all power to the starters, Scotty!

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I've had relatively limited experience with different vehicles in this regard, so thought I'd reach out to you all.

On my car, my mom's XC70, and my dad's old S40, all noncritical electrical items (lights, climate control, aux 12V sockets, etc) are shut down while the engine cranks. This makes sense as these systems can use in excess of 40 amps, and turning them off makes that much more cranking current available to the starter. Downside is anything running on accessory power will shut down and restart after the engine cranks. Dashcam works fine with internal battery, but my custom gauge with data logger needed a hefty capacitor bank and regulator to stay on when starting.

However, on my dad's Subaru Crosstrek, essentially all loads remain energized. That combined with a smaller battery means the little 2L boxer cranks over much slower with noticeable strain in the cold compared to the larger Volvo engines despite the Crosstrek using 0w-20 oil and the Volvos using 5w- or 10w-30.

Do your vehicles automatically shut off accessories while cranking, or leave them on and rely on the battery to deal with the extra load? Do you manually turn off items before cranking on very cold days or when you suspect a weak battery to squeeze out some more CCA?
 
It varies from MFG to MFG ...

The big deal is to make sure there is a clean solid ground path to the Bat Neg (-) for both the engine block and the chassis/dash. A hunk of #4 welding cable with crimped and soldered ends going from bat to alternator mounting bracket usually helps a great deal
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My wifes Audi and my GTI are sticks and the headlights turn off when starting the engine. It kinda sucks because I put a heavy duty clutch and pressure plate in my GTI which makes it easy to stall and can potentially draw attention to a cop. I did own a WRX once. I seem to remember that car never did turn the engine over fast when starting it regardless if everything was turned off or not. It reminded me of a 49' Mercury my dad had when he was into old cars.
 
Originally Posted by skyactiv
I did own a WRX once. I seem to remember that car never did turn the engine over fast when starting it regardless if everything was turned off or not. It reminded me of a 49' Mercury my dad had when he was into old cars.


Interesting. Perhaps a Subaru quirk, then? My dad's never seems like it would fail to start, but always sounded far more strained than it should for a modern vehicle with 12 volt system and oil meant to flow well at freezing temperatures.
 
I usually shut down accessories just before turning into my driveway so I never noticed whether the system shuts anything down when starting the engine.
 
My wife 2018 VW Tiguan flickers headlights and wipers off during start. A bit weird with auto start stop at night with a light rain. The lights dim and wipers stop mid stroke while motor cranks.
 
My Vic does reboot the (aftermarket) stereo when starting (if I was listening in the accessory position) but my Super Start Platinum AGM battery cranks fast and strong and it fires right up. I have the DRLs disabled so the headlights aren't part of the equation. My 12V socket is always powered, key on, key off, cranking....

I barely ever drive the Escape so I have no idea if the stuff stays on.
 
Dogememe, that's a strange one with the CV. That shouldn't be happening with the aftermarket stereo. I never had that issue in any of the cars in that platform I've driven over the years, unless something changed somewhere after the 2000 or so model year.
 
company A may put a lower geared 1.2 KW starter, company B may use a 1.8KW for the same displacement engine.

If you can tell me the years of the vehicles I can see if i can find the KW of the starter listed.

Rod
 
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Originally Posted by Garak
Dogememe, that's a strange one with the CV. That shouldn't be happening with the aftermarket stereo. I never had that issue in any of the cars in that platform I've driven over the years, unless something changed somewhere after the 2000 or so model year.


I'll attribute it to being an ex-cop-car with hacked up wiring... it's a little annoying though, some day I might come up with a solution.
 
Originally Posted by dogememe
Originally Posted by Garak
Dogememe, that's a strange one with the CV. That shouldn't be happening with the aftermarket stereo. I never had that issue in any of the cars in that platform I've driven over the years, unless something changed somewhere after the 2000 or so model year.


I'll attribute it to being an ex-cop-car with hacked up wiring... it's a little annoying though, some day I might come up with a solution.


It's normal behavior for how the ignition is wired. My 09 Grand Marquis does this as well. To be fair to Ford, the factory radio was an am/fm/cd/cassette unit with hardly any startup lag and Bluetooth pairing wasn't a consideration.

If you don't like it you can try jumpering the accessory (or specifically the head unit) and starter wires off the ignition switch with a diode and/or a really big capacitor.
 
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Originally Posted by ragtoplvr
company A may put a lower geared 1.2 KW starter, company B may use a 1.8KW for the same displacement engine.

If you can tell me the years of the vehicles I can see if i can find the KW of the starter listed.

Rod


1998 Volvo V70 GLT
2014 Subaru XV Crosstrek

Would be cool if you could hunt down the specs.
 
I don't do accessories, but much prefer a vehicle that turns the lights out when I switch off, and shuts them down when I crank. I hate all the warning beepers in Japanese cars when you leave the lights on.
 
Originally Posted by HorseThief
It's normal behavior for how the ignition is wired. My 09 Grand Marquis does this as well. To be fair to Ford, the factory radio was an am/fm/cd/cassette unit with hardly any startup lag and Bluetooth pairing wasn't a consideration.

I was going to ascribe it to hacked up wiring like dogememe mentioned. The older Town cars and CVs with which I had experience certainly did not have this issue. Also, one also never knows how good the stereo install is. I've seen some very poor behaviour on even older cars, some GMs I've seen, that certainly should not have been there. If a stereo gets reset (particularly the clock and audio settings), I'm not going to be satisfied.

As for CVs, I've seen some real messes where the post garage had done DRL disables that didn't work all that well, and that's excluding what was done for getting a light bar, radio, and siren to work.
 
Originally Posted by VeryNoisyPoet
Originally Posted by ragtoplvr
company A may put a lower geared 1.2 KW starter, company B may use a 1.8KW for the same displacement engine.

If you can tell me the years of the vehicles I can see if i can find the KW of the starter listed.

Rod


1998 Volvo V70 GLT 1.4KW 9 or 10T pinion
2014 Subaru XV Crosstrek 1.2KW 8 teeth pinion

Would be cool if you could hunt down the specs.


Here ya go
My motorcycle, a 1.2L 2 cylinder BMW with 12 to one compression is another that seems to crank slowly, BUT it always starts right up in any weather I would ride in. (15F) with 20W50. The starter is a Bosch listed at .9 KW. Mt older beemer has a Valeo listed at 1.2KW and it always seemed to crank faster. The fewer cylinders the harder the engine is to crank all other things being equal.

Both always start which is what matters .

Rod
 
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