Crazy electrical problem

[BgEoEdR]

When i start my car sometimes the greeting under the speedo/tach doesnt appear but the door buzzer/dingdinger keeps going off and the back light behind the screen will come on when i press the brake and turn off when i let go . if i punch it in neutral or 1st when the tach goes a little past 4grand the greeting will pop on and i can recall the obc values that have programed whereas before i hit 4k i get nothing from the dash display for the obc.
Anything guys ive got no clue, i was kinda thinking that maybe the electrical system was not holding enough watts/amps/chargeinbattery and then when i excede 4grand the alternator is pumpin enough juice to get it going but i dont know it dont effect driveability so im not trippin but it kinda drives me nuts

[winfred]

i was told about a tsb (technical service bulleten) that was on the subject of weird cluster power activity and the root problem was a defective aux water pump for the heater, it's below the heater valves next to the fusebox, i think unplugging the pump should tell if it's the cause if the problem goes away

[BgEoEdR]

Its sounds kinda out there, and I dont know what the pump looks like but i will go out and look tomarrow. if that is the problem,the solution would be a simple replacement of the pump(how simple is this stuff ever really)? Thank you very much.

Any body else reading this if youve got other ideas as to what it could be any input is appreceated.

[winfred]

it's only about 20% ******** as the tsb is from bmw, heres a pic of the pump and heater valves, it's # 1

[Bill R.]

his though, usually i see this when the capacitors in the dash cluster have gone bad. One of the first symptoms is as soon as you hit the break pedal the chime goes off. And then once you raise the rpm up aways everything goes back to normal.. The trip odometer usually resets itself back to zero also... I think that the bad capacitors in the dash won't hold a charge like they are supposed to, so when you start it up everything resets since it lost memory power and when you rev the engine up the alternator puts out enough that the dash capacitors get charged back up after a few seconds.

i was told about a tsb (technical service bulleten) that was on the subject of weird cluster power activity and the root problem was a defective aux water pump for the heater, it's below the heater valves next to the fusebox, i think unplugging the pump should tell if it's the cause if the problem goes away

[winfred]

i have a customer with a early e32 that has a problem sorta like he describes and it's whipped almost every bimmer shop in town, i've swapped damn near everything without effecting it, went over it with a fine tooth comb when i did a heater core last year and had the dash gutted, we came across this tsb about a month ago and fixed a early 750il with it, haven't had a chance to try it on alex's car as it's not returned for service yet and he just ignores it

his though, usually i see this when the capacitors in the dash cluster have gone bad. One of the first symptoms is as soon as you hit the break pedal the chime goes off. And then once you raise the rpm up aways everything goes back to normal.. The trip odometer usually resets itself back to zero also... I think that the bad capacitors in the dash won't hold a charge like they are supposed to, so when you start it up everything resets since it lost memory power and when you rev the engine up the alternator puts out enough that the dash capacitors get charged back up after a few seconds.

[Bill R.]

just fine..

i have a customer with a early e32 that has a problem sorta like he describes and it's whipped almost every bimmer shop in town, i've swapped damn near everything without effecting it, went over it with a fine tooth comb when i did a heater core last year and had the dash gutted, we came across this tsb about a month ago and fixed a early 750il with it, haven't had a chance to try it on alex's car as it's not returned for service yet and he just ignores it

[winfred]

we've had several different clusters in it with no change, about the only thing that hasn't been swapped is the body harness

just fine..

[Scott E]

A while back my LCD cluster stopped working all together. I ended up replacing it with another used cluster which has been fine except for the trip meter resetting when I start the car. Lately there are times the LCD display stops working and shutting the car off, then back on usually fixes it. Other than the trip meter resetting and the LCD panel not displaying I dont have any of the other symptoms of capacitor failure (which still could be the problem).

Also my heater works marginal at best. Unless the car is moving and the driver's dial all the way to the left I am lucky to get any heat.

I wonder if my aux water pump is faulty thus causing these problems? I have cleaned the heater valves but I suspect I really should replace both the heater valves and aux water pump. (been telling myself next winter for 3 years now). Since I live in SoCal having a heater isnt a priority.

Thanks for the TSB info (that goes for you too Bill R)

[bimmerd00d]

my aux pump randomly started functioning this year, about the only good thing about my car