Warning light problems

[ChrisHC]

I have a persistent problem with both the brake pad wear indicator light and the brake light failure warning light on the check panel.

Brake pad light
This comes on and off at irregular intervals (it does not flicker). This occurred with both the original brake pads and replacement pads. The wiring to both pads has been replaced. I have taken out the dash cluster and checked the solder joints on the pad wear resistor, as advised in the wiki. They seemed fine (the dash cluster has been replaced at some stage) but I applied a soldering iron to make sure.

Brake light failure warning
This again comes on randomly. Because the lenses were cracked, I have replaced both rear light units but this has made no difference, so I do not think it is a genuine warning coming from an intermittent fault. When first starting the car, the light comes on until the brakes are first used, then goes out as it should.

I am at a loss as to what to do next, but could these faults be connected in any way?

[Gavt]

The brake bulb warning is normal it's only knows it's working once tested.

[ChrisHC]

The brake bulb warning is normal it's only knows it's working once tested.

Yes, as I said it comes on when first starting until the brakes are used as it should do, but the point is that it comes on randomly at other times as well, which it should not do.

[paultv]

Brake Light warning

I had this problem over a long period, turned out to be the earth connection between the metal carrier plate which the bulbs are plugged into and the earth wiring held in the plastic body of the lamp unit. The metal carrier has a flange which pushes into the female "socket" when you clip the two together. I cleaned both flange and clip, but they still didn't make a good reliable contact, so I soldered a short length of cable between the two, allowing you to open the unit if needed.

It's been fine ever since, I only needed to do this to one side of the car, the other was clean and caused no problems

This maybe your issue... worth a look.

Also look at the connections on your rear lamp check unit and the internal condition of it too. Also the main earth under the back seat, left side.

Paul

[ChrisHC]

Thanks Paul, that's helpful. I did squirt some switch cleaner on those contacts but they might be dodgy. Did your poor earth connection not affect the other lights in the cluster?

[paultv]

Yes probably, but during the summer most driving is without side lights, it was always a random brake warning that popped up. Every time I checked the brake lights they were working, so probably vibration when driving causing an intermittent connection.

To solder to the metal plate I cleaned it with 200 grade emery and used a gas powered kitchen Creme Brûlée blowtorch to get the solder to tin.

Paul

[ChrisHC]

I suppose I might sneak the kitchen blowtorch out to the garage when the other half is shopping!