Battery Connect Switch unit 2005 DB9
 

Hi All
First post so please be gentle!
The battery connect switch had a few issues "staying" connected and the red warning is no longer visible, so decided to put a new one on the car, and rule that out from the other ongoing issues (some solved, bad earths/wiring) others time will tell as intermittent ... but the first switch that arrived from the dealer had no 18ohm coil reading, just open circuit and so would never latch!
The second switch, has 18ohms for the coil, as the existing switch does, but this new one (from the main dealer again, under warranty), jumps open everytime you press start. Test is unlatches via the boot switch once latched and that works, but everytime you press start it jumps open ... disconnect it and leave it, connect it, latch it ... wait for 20minutes (coil should be sturated in milliseconds) and smae thing it just unlatches and drops the power.
Put the original one on, test all it, both latching and unlatching from the boot, all fine, car starts fine ...

Asked dealer and their technicians if there has been issues or bad batches, and nothing. They have no idea.

Is this something people have seen/heard of, or a known issue, either with the switch or maybe excessive starter inrush current?
Will measure current on a scope next week, but it's not even audibly throwing the solenoid of the starter, so not sure it can be getting near normal cranking amps ...

Just curious if this is a previously discussed issue?

Thanks in advance.

Bypass the switch, you don't need it, do you? The disconnect button (and reconnect) is just a failure waiting to strand you. The more you use them, the sooner they fail, so never use them!

It is simply a flimsy switch. I tried it once to see how it worked and thought I better not use that too often. Haven't touched it since.