dashboard loud warning sound

[Bill Lee]

I'm having a really difficult time trying to obtain the source of a type of reaction my t4 7da aac transporter gives;
When the engine is turned by the starter motor and (due to an other problem getting fixed) would stop rotating due to a quickly flattening battery, hence the release of the key to on only...when it happens in the dash.
When that ignition turning over can't anymore ,the dashboard winks, clearing all the data to 0's, except the speedo and .....it happens on the right side.
I've taken the dash off to get the immo and only have the dash display and light switch/dimmer module to blame for the noise, there are no other items.
.........IT being a rough mechanically turning cylinder filled with ball bearings, or cash register calculating crunching, loud wire brush noise....for about 4 seconds and automatically stops again as it had started. There is no limit to how many times it can do this, as long as the vehical tried to start but not actually fired it will respond, for some unknown reason.

Is there an alarm type of instrument in the dash display responsible or in the right hand main light switch?? Both large enough...only other thing is the brake drum or fuse area?!

HELP.

[Umai Naa!!]

Could be all the relays under the right side of the dash not being able to properly engergise due to low volatge.

[JustCruisn]

You hear a fast clicking sound in the dash then the battery is flat and you try to start the engine ?
This is the relays flicking open and closed, this is a symptom of the low battery voltage. The relays latch closed (click), which draws too much power, voltage drops, the relays open again (click) as there is not enough current to hold them closed, now voltage is high enough and the relays latch closed again (click), repeat....
click click click click.....

This video demonstrates the issue https://www.youtube.com/watch?v=YhhycnO14Ko

[Bill Lee]

Both of you just won a very big prize..(the crowd roars!)

That is soooo close its not funny. Too balmy for words. A less defined clicking and a more wirery brushy per wire, fasterish, in a plastic can. In the dash. Very accurate to almost similar. The battery would go flat because the starter motors plastic planetary part was smashed and the internal motor would slow the crank for energy & graze the outer...arc on the earth......so a lot about it.

Which relays....all?
A creshendo of relays....transfered by the frame to the dash....balmy!
Does anything turn in the main light module?
Good one!. Thankyou!.

[Umai Naa!!]

What testing equipment do you have?

Clearly, there's a low voltage issue going on here.

[Sunny43.5]

I agree with Umai low voltage problem for sure , my son's T4 used to do the same lots of fluttering sounds and usually followed by trip meter going back to zero along with clock . A new heavy duty battery with high crank hour rating solved it plus cleaning all earth straps and connections to the body etc.

[Bill Lee]

Right again, new battery required.
The starter motors plastic planetary gear cup was smashed inside, but was held in by the housing and could still rotate, although it now wasnt aligned straight any more. There are graze marks on the motor from the magnets that I guess shorted it out every turn until the battery went flat quicker+ older battery+ quickly dead. It was also the cause of burned out parts, really having to go over all of it with a fine tooth comb.