Warning Lights on Disco I

I have a problem with my 95 Disco 1. My Service Engine light is on, and my SRS light, and my Anti-lock light. I have looked at my brakes and everything seems to be in order.I had to replace the brakes when I bought it and used aftermarket brakes.I talked to a dealer and they told me that using aftermarket brakes could cause all three lights to come on.I have disconnected the battery in hope that if that was the case, disconnecting the battery would reset the lights, but it didn’t, is there a way to reset the lights in order to start troubleshooting what the cause could be?I do not have a code reader, or a MOTIS.

There are 3 different systems here.
Service engine light is mileage related. Next to your ECU there is a brown relay, with Emission reminder marked on it. This needs to be reset.
2. SRS Light is related to the Airbags, so either the spiral cassette on the steering column is messed up or there is a sensor problem.
3. ABS light is usually either a bad hub bearing or a bad ABS sensor (generally speaking).

Hope this helps.