Brake and turn light issues....

[Manhorne]

The never ending saga of electrical issues.
So My turn signals stopped working yesterday when I was out driving. So I spent the day today troubleshooting the problem with the maintenance manual . As I was doing this my Driver side brake light has stopped working now. The passenger side brake light works fine and all the other tail lights work ok it is just the turn signals and the driver side brake light are not working. I took a voltage reading on the driver side with the brake pedal depressed and I am only getting 6.5 volts on that side. Before it stopped working I had 25volts there and both brake lights were working .

I am at a loss. I am dreading that maybe the rear wiring harness is bad . I checked the grounds and they are good. The turn signal switch seems good to me. I did test the signal lights with the brake depressed and when the turn signal was engaged the corresponding brake light would go out. It was after I was testing this that the driver side brake light stopped working. Could a bad Turn Signal controller cause this issue?

[m3a1]

That may very well be, but you might also want to check the health of the bolts that hold the composite lights on. Each one is an independent ground.

Cheers,
TJ

[svramselaar]

hi

i do NOT use a voltmeter to check wiring and lights
allways a testing light with a 2 watt bulb NOT a led
the problem with a voltmeter is it uses no amps so if there is bad connection the voltage is there no working light
a bulb uses a bit amps so with a bad connection it wil not light up

https://www.google.com/url?sa=i&url=htt ... AdAAAAABAL

if you take the connector no 22-461 at the left light off look with a light if it works (testing light at body for ground )
if yes put it together and test at the bulb socket (testing light still at the body )
if yes at the socket put the test light wire from the body to the ground of the socket if not you have a ground problem )

if not at the connector do the same at the connector beheind the dasch
if not try the same at the directional switch if not switch is not ok

[Manhorne]

That may very well be, but you might also want to check the health of the bolts that hold the composite lights on. Each one is an independent ground.

Cheers,
TJ

I will check that.

The driver side housing was very dirty when I opened it up...the passenger side still looked brand new inside. I ordered a new Signal Controller because I feel my turn signal issues are with it because they had been acting up the past month or so before they died. I am hoping that it also fixes the driver side brake light issue as well. It was after I was testing the turn signals with the brake lever depressed that the driver side light stopped working and I started to only get 6V there. I know a bad controller can also cause problems with the brake lights too from what I have read.

[rickf]

The brakes and turn signals go through the signal switch on the steering column. It sounds like the contacts in there have gotten dirty. Once you get the new one take the old one apart and clean the contacts and it will be good as new.

[Mark]

I thought the way to clean the contacts is move the lever back and forth to one extreme to the other several times kinda fast.But I could be thinking of the light switch

[rickf]

Sometimes that works, it works a lot better on the light switches.

[muttguru]

Ken

[Fil Bonica]

Keep in mind the brake switch # 75 goes through the main light switch.
That too could have defective contacts.
Exercising that switch may help.
If you have a new one try that out also.
Dont nake changes on both switches at once.
Do each separately.

Fil Bonica

[svramselaar]

hi

he has only a problem with the left side
it is at the light itself or the wire from the directional switch no 22-461
to scheck the wire you can also look if there is power at the trailer receptacal stop and directional light

at the light switch go wire 75 stoplicht for both rear lights to the directional switch
from the directinal switch go wire 461 to the front and 22-461 to the rear for stop and directional light left


george

[Manhorne]

Ok. So I have done some more troubleshooting today after I got home from work.

I checked the continuity on 22-461 on the rear wiring harness and that was good. I checked the same on the cable that goes from the turn signal switch to the connector that connects to the wiring harness and that tested ok. I checked for voltage on the trailer receptacle for the LH stop light and there was little to no voltage. I checked the voltage at 22-461 at the connector that goes from the Switch cable to the wiring harness and there was no voltage there. So I am assuming my problem is most likely the turn signal switch or the flasher directional control box....

[rickf]

The fact that on one of those checks you had low voltage would tell me you had a dirty connection in the switch. The headlight switch used a sliding bar and contact but I believe the turn signal uses a roller and detents, hence the smooth movement. The headlights are designed to be turned on and off occasionally where the turn signals are designed to be used often. Sliding metal contacts would wear out quickly and also would be too rough to use in that application.

[Manhorne]

The fact that on one of those checks you had low voltage would tell me you had a dirty connection in the switch. The headlight switch used a sliding bar and contact but I believe the turn signal uses a roller and detents, hence the smooth movement. The headlights are designed to be turned on and off occasionally where the turn signals are designed to be used often. Sliding metal contacts would wear out quickly and also would be too rough to use in that application.

I was just looking again at the schematic and with what I know you maybe right. I am going to take the switch out and check it and test the voltages there.

UPDATE: I took the light switch and checked and cleaned the contacts . I then checked the connector. I jumped pic F (24V) to pic C the stop light connection and the driver side stop light still does not work. So the light Switch is not the issue. The only thing I can think is left is the turn signal switch. I opened it up and checked everything in it and did not see anything obvious wrong with it . I had ordered a replacement one so when i get it i will see if that fixes the issue.

[Manhorne]

So in the end the problem was the turn signal switch. Installed a new switch and everything works as it should....