Originally Posted by
teacherjim69
They said the lights had come on because
i had unhooked the battery as I installed the rcm.
Disconnecting the battery does not always cause the brake controller to lose its mind and turn that light on. But it sometimes does.
The better way, is to not disconnect the battery just for an RCM job. The RCM is a power distribution device, all it is, is relays and fuses. There is no reason to disconnect the battery when removing or re-connecting the RCM.