skratch77

I know that this thing draws some power and need to tap into somewhere so I can run the pump with a switch.

I babied my car last night and it usually is fine(or I never bothered to check)at the track but last night I was idling around 120 iats.

As you guys know,if you dont drive on boost the pump wont come on so I was thinking of a switch instead of having it stay on all the time.

Thinking of just tapping the second batt under the hood?

shardul

iTrader: (1)

dont touch the second battery i have know people who have had issues when they tap into the second battery.
Just run it all the time. I have had mine like that for 2 years now. when the car is running there is sufficient power so you dont have to worry about the pump.
Or leave it like the stock configuration so the euc tell it when to turn on under boost.

Jakpro1

Nah, don't mess with acc battery. It's your lifeline if car stalls for braking.

Run it off a fuse from the ECU area that turns on and off with Keyswitch.

Heads up that some of our guys claim that the ECU keeps it running nearly all the time besides cold start idle/warmup (thus no need to do this)

I never confirmed that but here is the info you need if you wanna run it off Key. I am off keyswitch and love it. No issues.

chiromikey

yep, i'm one who has confirmed (at least on my car) that the ecu runs the pump all the time. obviously, living in the desert i've never been able to test it in ambient temps lower than 60*. i do have a manual override switch tapped into the main battery for my pumps and fans but that's for track use when the engine is off.

lowprofile

Mine is the opposite. The pump will not turn on in the staging lanes while cool.
There was a thread a while back where someone tapped one of the lines from the fusebox under the hood. I will see if I can find it for you.

mikey33

Tapped mine from the fuse box in the engine compartment with a relay and runs with the key in the ignition all the time. No problems thus far.

lowprofile

Alright Angelo, I have some good material for you.

First up: Vrus states that between my03 and my04 , MB changed the programming for when the pump activates. This would account the difference that myself('04) and chiromikey('03) have experienced. Read post #8
https://mbworld.org/forums/w211-amg/...ater-pump.html

In this next thread, Brian S has photos of where he tapped a 12v accessory source to activate a relay for the i/c pump. This means you would have to wire in a relay.
https://mbworld.org/forums/w211-amg/...nger-prep.html

skratch77

Thanks alot,some good info in there and my05 def turns the pump on while on boost,so when youre in the stageing lines the thing is heat soaked before you even run.

I was also thinking of running a wire right to the main bat with a switch and leaving the rest of the setup alone.

So leaving everything stock and adding a 12v positve right from the rear bat to the pump.That way I just hit a switch and it sends the 12v to run it while staging and then shut it off when I dont need it.

What amp fuse say 15? Need to see how much power the stock pump draws.

PS Im sure ill find a 12v line somewhere in the engine bay too,like the one in the fuse box

shardul

iTrader: (1)

there is a 12v switched power supply in the ecu box. it will turn on pump when ignition is in position 1