engine and drivetrain Mythbuster type electrical load questions

[SteveJ]

What would happen to the electrical system on our 02's if EVERY electrical item was in use at the same time?

Looking to see if anyone here knows the power consumption of these items on a 02. I already have all the light wattages. Otherwise I have to break out the meter and do it right.

Warning indicators (L,O,etc)in cluster = 2watt or 3watt?

tii fuel pump =

rear window defrost =

wiper motor on low =

wiper motor on high =

blower fan on L,M,H =

stock single speaker radio =

interior light =

The tii alternator is rated at 45amps/650 watts. I'm just curious to see if everything adds up to 650 or how much of a cushion they engineered into these cars.

[Neil_in_PA]

Hehe...next post you submit will be..."How do you get the smoke back in all them wires?"

Interesting question, for which I do not have answers off hand, but I will research. I know when I worked on BMW motorcycles, /2, /5, /6, /7 vintage, it always seemed that the engineers at BMW never thought that EVERY accessory will be on at one time! In other words, the charging systems were less than, shall we say..."up to snuff?" Interested to see what the answer is.

[Matt_B]

do you know who that guy was at the car control clinic that was taking pictures? i would really like to get some pics of my car in action. thanks

matt

[Beaner7102]

Warning indicators (L,O,etc)in cluster = Should be 3watt - dont forget dash lumination

interior light = 5w

Beaner7102

[Paul7002]

(nt)

[Napes]

(nt)

[SteveJ]

Yeah,

I'm gonna throw the brights and the wipers on full, ~then~ lay on the horn.

The neighbors are gonna think I'm drinking in the garage again.

This all stems from the one time long ago with my first 02. Warm summer night, deserted country road. 100watt H4s, plus some extra 60watt fogs for periphial vision. The blower fan on low to keep some air moving inside, the electric fan on the motor, and a decent(for the time) stereo playing Alan Parsons at a healthy volume. As I come down the hill towards civilization, the whole car browns out and stops running. I coast into the lighted parking lot and check things out. Everything is connected fine, there is just no juice to start it. I shut everything off and after a while I am able to crank it over very slow and start it for the quiet, dimly lit drive home. All I could figure is that I was just drawing so much that the alt couldn't keep up and I drained the battery. It sure was fun, though.

So,

just how much stuff can we add to a stock system before the alternator says, "Hey! Wanna see my Lucas impersonation?"

[TJs692002]

I just went through this. I fried a couple of voltage regulators trying to see what the 318i 65 amp internally regulated alternator can handle. My car is a 69 2002, mostly stock. With the motor running, I can have the headlights, wipers (on low speed) and heater fan running (high speed) and the car will continue to run when I disconnect the negative from the battery. Now with the car still running, battery ground not hooked up, I turn on my 180watt each KC daylighters (I have two) and the voltage regulator instantly fries and the car dies. Now 180 and 180 equals 360 right? If the alternator should be good up to 640 watts I really dont think the headlights, wipers, and heater fan uses more than the 280 watts that are remaingin in our equation. I do not think that the alternator can handle much more than 200-250 watts.

[SteveJ]

THAT is what I am talking about!!!!!!

My car is a fairly stock tii. I have a wimpy little stereo added in (to keep the wife happy on long trips), but I want to add some H4s of the 55/60w variety. I also have some period foglamps that are 30 or 40watts each.

I just don't like the idea of having to not use the hair dryer when the microwave and coffee pot are in use.

Driving at night. Someone pulls out in front of me. I honk my horn and everything goes out. The person looks in the direction of my horn and now sees nothing in the darkness.

Maybe I should design an emergency lighting system for our cars?

[jrhiddle]

is 100 and that power (watts) equals amperage times voltage (12V) then the total power needed would be under 1200 watts. If the circuits were designed for only 2/3 of the fuse capacity, that would still be 800 watts or about 67 amps needed. Clearly the stock 45 amp alternator wouldn't be up to it.