Anyone tell me the acceptable amp draw is ?

With radio fuse removed

Fuse refitted

After about a minute with fuse in

 

MAX 0.05 Amp, or 50 mA.

 

Drain obviously seems related to the radio.

0.06A is within the accuracy of DVM which is typically 1%+/- 1 digit so probably is 50mA

Note the H2 takes some time to achieve minimum current drain, several minutes if I recall correctly which maybe why you have different figures when the fuse is in.

It would be worth checking the circuit diagram to see what else is connected to the radio fuse as I don't think the radio is hot all the time.

 

Retained Accessory Power (RAP) after timeout(approx 20mins), should be below .03amp.

 

When this happened to me- I had installed an aftermarket bluetooth module that integrated into the radio & onstar wiring..Blue fusion I believe it was called...
so- anything aftermarket (alarms, adds, etc) start disconnecting there

 

Thanks for replies, it has an aftermarket previously fitted, slowly working through it, finding wires twisted together etc. No factory amp either. Steering wheel buttons don't work although there is a adapter fitted, but seems to be an obsolete one.