🚀 go-pugleaf

Hello!  A car electronics question for some clever soul:

I have an older Toyota, a Celica GT, 1977, which has a box to
monitor fluid levels, brake wear, etc.

This device, which they called an ESP, senses the electrolyte
level in the battery (or it used to!).  The current battery
has no provision for such a device.  Now, the question:

How do I shut up the warning light?

  1)  I don't want it all unhooked, 'cause it works.

  2)  I tried grounding the lead, hooking the lead to
      +12, and leaving the lead disconnected.  Nothing.

  3)  Apparently only one wire went to the device.  Can
      anyone confirm/deny this.  I didn't have the car
      then.

  4)  The battery level IS OKAY.  Yes, I checked, just in
      case the thing really does have ESP!!!  :)
Thanks for your time!

Paul