SI Board Enigma

[dave783]

Greetings everyone, I need assistance in determining the specific BMW model associated with a SI board I purchased second-hand.

I own a 1988 E30 318i. A few weeks back, I removed the SI board and changed the leaking batteries while attempting to rectify issues with the rev counter and the service lights malfunctioning. My original SI board sustained significant damage from the acid leak, prompting me to purchase a secondhand replacement, anticipating it would be in superior shape. The board I discovered on eBay seems to be in excellent condition, however the batteries have seen little leakage, which I can replace with relative ease.

My inquiry pertains to the fact that some electrical components on my new board seem marginally different to those on the board now installed in my vehicle. An E30 board, originating from Germany, was sold to me.

I have attached the board I acquired; could anybody with expertise in BMW SI boards ascertain if it is an E30 board?

Thank you!

[dave783]

[IrvesBMW]

Please provide images of your original PCB that has sustained significant damage from battery acid.

[IrvesBMW]

Or maybe not!

[dave783]

Upon removing the old board, I neglected to get a full-length photograph, resulting in just a partial glimpse of the original board. Refer to the attachment. The acid corrosion has eroded the printed connectors on the circuit board. I lack a functional rev counter, the brake light is always illuminated, and the service lights are exhibiting erratic behaviour.

Refer to the attached original board. The electrical components and layout are distinct when comparing the original and replacement boards. I lack expertise in electronics and find it challenging to comprehend onboard components, such as capacitors. The new board seems to be in decent condition; I can easily change the batteries. There are some green flecks on the printed connections, but I can clean them gently with a toothbrush and some electronic solvent.

Thank you for your assistance.

[dave783]

All pins seem to align properly, and it is the older model with longer batteries. Could my new board originate from a non-E30 model or a six-cylinder vehicle? I own the 1988 E30 318i once again.

[IrvesBMW]

I would be pleased to examine your original PCB, since it seems you have already deemed it unserviceable.

[dave783]

Thank you for the proposal! I reinstalled the original board in the vehicle after replacing the batteries, anticipating that everything would function correctly; however, this was not the case. The rev counter remains inoperative, the brake light is constantly illuminated, and the service lights are blinking.

I must remove the board once again to get assistance from someone to examine it. My intention in purchasing a new board was to get a quality option and rejuvenate the batteries. I desire to ascertain if the replacement board I acquired is intended for an E30, since it closely resembles the one now installed in my vehicle. One method to ascertain functionality is to put it in my vehicle and observe the behaviour of the gauges and service indicators. I do not anticipate causing any damage to the gauges, or at least I want to avoid it.

[IrvesBMW]

I will interpret your reaction as a negative. I wish you happiness in all your endeavours.