It is interesting how things tend to cascade from bad to worse when dealing with automotive problems. While driving the other day and executing a left turn I noticed that the blinker indicator on my dash was blinking a lot faster than was usual. In the past this symptom has been the result of a bulb having gone out.
In due course I stopped at an automotive store and purchased a pair of new bulbs. While on the way to my home I went to make a right turn and discovered that the same problem was present there as well. The blinker was operating a lot faster than it should. The problem had suddenly doubled in severity. I pulled over to evaluate the problem and soon discovered that I not only did not have signal lights, I had no brake or tail lights either. This was serious. I could easily get rear ended with no lights back there. What was worse, night had fallen and now an approaching driver may not see me until they were on my rear bumper. There was nothing I could do except activate the four way emergency flasher and suffer the flashing until i made the house.
I was within a mile of home when the four ways gave out too. I was left with nothing but the headlights and dash panel lights to drive with when, yes, the dash lights went away too. No further failures occurred and i made it home safely. I knew that tomorrows priority would be taking a look at the lights to try and determine what was going on and affect a repair.
In the American manufactured automobile, the tail and brake light must first travel to the signal switch located in the steering column. And from there the voltage is routed to the appropriate bulb. The reason it is done this way is just a practicality. In European cars, the lighting system is wired differently.
I checked the bulbs in the rear lights with an ohm meter and found they were ok. I traced the wiring harness under the truck and discovered that a portion of the wiring leading to the lights had been cut by a sharp edged body member. Two of the four wires had been severed. This would have grounded the live wires and led to a fuse failure and this is probably what happened to my dash lights. I repaired the wires by stripping the ends free of insulation and then used crimp connectors to fasten the two wire ends back together. It is always a good idea to protect such a connection from weather and road salt so I used a silicone sealant over the entire repair to seal out moisture and salt. A check under the dashboard at the fuse panel revealed a blown fuse. However replacing the fuse only brought back the dash lights. The initial problem of no tail or signal lights remained.
Since the voltage to power those lights passes through the signal light switch in the steering column it would be required to remove the steering wheel and replace the switch. Removing the steering wheel would require a specialized tool which I could pick up at the auto parts store when I went to get a new signal light switch and four way flasher.
Back at the house with the required tool and the new switch, I set to work. First the battery cables are disconnected. Then the horn button is popped off. Under that is a large nut holding the steering wheel tight to the steering shaft. That nut needs to be removed and then the puller can be applied. Be sure and make a mark on the steering wheel and the steering column before removing the wheel. You must align these two marks up when replacing the wheel. otherwise you may find yourself driving down the road with your steering wheel seriously sideways or something. With the steering wheel off I can now get to that pesky signal light switch.
It needed a lot of tedious effort but eventually I got the new switch installed and the wheel tightened back down. Reconnecting the battery and flipping the ignition to the run position I tested the signal lights and was pleased to see all was well. It was now time to see why the last failure, the brake lights were not working.
Having suspected the cause of the problem I had also purchased a new brake light switch while I was at the auto parts store. Installation of this switch is fairly easy on my vehicle. The switch clips to the brake pedal in such a way that by pushing down on the pedal the switch moves away from a stop pad and the spring loaded switch lever is released and turns on the brake lights. I had it fixed in ten minutes and now, I had a full set of working lights. Brakes, signal and tail lights.
I suspect that the brake light switch had been out for some time and it only came to my attention when the signal light switch went away. As for the broken wiring, that was real recent else wise the dash lights would not have gone away along with the fuse. A cascade effect. The brake lights go away when the switch fails. The turn signal switch failed and took the turn signals with it. And the dash panel light and tail lights went when when the wires got grounded.