Richard. All TEA20s were Positive (+) ground/earth ex factory.
Lonnie. I have an after market wiring loom in my TEA20 and it seems fine, but as Charles suggests it is easy enough to make one. The TEA20 wiring diagram is very basic and elementary.
Sparex produce a wiring loom for the TEA20, part number S.67037.Wiring Harness
Sparex is a wholesaler only. Most agricultural parts dealers, including this site, are Sparex retail dealers.
Bob in Oz
'53 TEA20. This post was edited by Bob (Aust) at 13:22:39 07/23/14 3 times.