Thread: Brake Light Problems

Originally Posted by landychris

Could someone shine a little light on this problem (no pun intended)? I have fitted several brake light switches (the brass type) to my 82 Series III stage I. When I set up the switch and adjust the lock nut the brake lights work fine, then later for no apparent reason they don’t, and I need to adjust the switch again. On two occasions the switches which worked when installed proved faulty. One switch was even an original “Lucas Prince of Darkness”. Another new switch was installed during a recent service at a Land Rover specialist, as the vehicle had no break lights on inspection. The circuit was checked and the current draw was 2.8 amps. The brake lights worked again, but only for about a day. I found this out by being informed by a motorist with a few angry words and the middle finger, so after another adjustment, they worked again. Then not - adjusted again and working, then not and yadda, yadda, yadda. The vehicle has an electronic trailer brake unit fitted by the previous owner but this should not cause the problem. I replaced a similar switch years ago when I had a 76 Series III, this was a plastic type switch and I had no problems at all. The switch is a simple enough device, so is it just a case of my bad luck with these switches? Ideas please.......
Chris

Gday Chris, do both lights fail when it occurs? Switch test is easy, grab a multimeter, set it to ohms, connect one probe to each post and one way the switch should show continuity and flick the switch and it should cut the signal.

Youve used a few different switches so youd think one or more would work. i would think from there you need to look at the connectors and ensure they are clean at the wires as well as the connectors. Soldered connectors usually give better conductivity than crimped connectors.

From there trace the wires back , look for dodgy insulation(possible shorting) and clean up the earth straps and any other earthing points on the way.

Clean up the earths connections at the rear light inspection covers inside the back area near the lights, not sure if your rig is the same as a 4cyl SIII.

Another possibility is a weak or non-existent pedal return spring, meaning that the static position of the pedal keeps changing.

John

Thanks for the ideas Wallydog and JDNSW. Yes all brake lights work or don’t work. The rig is a Series III Stage I with an Isuzu 4bdi. Pedal return spring is ok. Will replace the connectors and see what happens then.
Chris

Originally Posted by landychris

Thanks for the ideas Wallydog and JDNSW. Yes all brake lights work or don’t work. The rig is a Series III Stage I with an Isuzu 4bdi. Pedal return spring is ok. Will replace the connectors and see what happens then.
Chris

ensure the when you strip the wires that the wires are clean. use good flux cored solder and tin up the wires and connector before soldering together. if you get a good solder joint it will last a long time. Good idea to Insulate the connectors with some shrink wrap if you want to.

It is possible there is a short somewhere else as well. It could be that every time you adjust things you move or pull on the wires enough to get things in a position it works but then after a while it settles back. Same thing can happen with the connectors as well so definitely replace them.

TimJ.

Originally Posted by Wallydog

ensure the when you strip the wires that the wires are clean. use good flux cored solder and tin up the wires and connector before soldering together. if you get a good solder joint it will last a long time. Good idea to Insulate the connectors with some shrink wrap if you want to.

And make sure the solder joint is shiny. Dull joint (Dry) = no good, shiny = good. If you get a dull solder joint, you are leaving the iron on the joint too long (All the flux is burnt away). A dull solder joint will result in problems later on.

Wolf

Originally Posted by Wolfman_TWP

And make sure the solder joint is shiny. Dull joint (Dry) = no good, shiny = good. If you get a dull solder joint, you are leaving the iron on the joint too long. A dull solder joint will result in problems later on.

Wolf

yes good point. I ve come across some wires recently while wiring in trailer sockets that were contaminated. Id apply heat and solder but it wouldnt take up the solder because there was too much contamination for the flux to cope with. Id cut back a bit and same thing. Ended up running new lengths of wire but i was amazed at how bad it was. It was always a dark brown look about the core wire strands. W

Originally Posted by Wallydog

yes good point. I ve come across some wires recently while wiring in trailer sockets that were contaminated. Id apply heat and solder but it wouldnt take up the solder because there was too much contamination for the flux to cope with. Id cut back a bit and same thing. Ended up running new lengths of wire but i was amazed at how bad it was. It was always a dark brown look about the core wire strands. W

Yeah, that usually means the wire has oxidised. I totally replaced my headlight wiring, for the same reason. The new wire is oxygen free, so shouldn't have any future problems with that. Plus, there was no need to solder, all connections were crimped.

Wolf