edain08

Here is what I got from Freightliner ZWiring schematicsD06-28749.pdf

also checked rear turn signal bulbs on right side for crossed filaments - nothing found All bulbs function

yes 1156 into 1157 replaced both flashers turn and 4 way Hazards appear normal except when headlights are on - then no flash - both before and after replacement of 4 way Bulbs I have replaced: Headlights Right turn signal 194 right side 1157 both sides 1157 trim bulbs both sides replaced 194 socket right side replaced 1157 socket right side replaced combiner ran grounds for right side

ok swapped out the combiner as well - still have the issue I have checked every bulb on the right side and removed each one in turn and still had the problem except for the time the 194 socket was replaced which came back the next day. I am flat out of ideas?? Any body got some?

Replaced the socket - no luck and am now replacing the combiner

Not when it happened. Just put in the wrong bulb type - Just for my info what is different about the LED replacement - I was going to do that later before all this happened

Any chance this is the combiner?

Well I think I spoke too soon. Problem came back this morning and would not go away. Its the front turn signal lamp and the issue has got to be there somewhere. I am guessing the 194 bulb just tripped me to the problem. I am going to try replacing that socket on a hunch. I could not find any bad grounds anywhere. I would run a new ground to the flasher but I am concerned that it might cause new issues. Any thoughts or ideas would be appreciated

Here are the results of my troubleshooting. The final answer did not make any sense but here is what I did. I started by removing the right rear taillight and examining the bulbs – no crossed filaments there. Then I turned on the right turn signal and started removing bulbs. I noticed that the flashers were acting strange so I replaced both flashers just in case they were part of all this but no luck there the lights just flashed better. After removing all the bulbs on the right side I still had the issue so I started replacing the bulbs. When I got to a 194-marker light I failed to seat the bulb properly and it did not light up – not paying any attention I went to get the next bulb and noticed the problem had gone away. I removed the 194 bulb and the problem came back – I put the bulb all the way in and nothing changed. I replaced the bulb with a new one and the problem continued. This perplexed me as this was not the bulb that I had replaced with the wrong bulb type. I ran a new ground for the socket and that did not fix anything. I cut both leads and removed the socket and nothing changed so I replaced the 194 socket thinking it might be bad and as soon as I put the bulb in the new socket the problem vanished. That was the fix.

Ok I will try and reply to all when right turn signal is activated with the headlights off - All the lights front, back, marker and clearance all blink Can you tell me what the combiner looks like and how I would check/replace an isolator?

Did something stupid and could use a little help with pinpointing where I need to look to fix this, 1999 DIscovery 36T Was troubleshooting some dim /burned out bulbs and put a single pin bulb into a 2 pin bulb socket - taking out the ground I suspect. Symptoms: with lights off - Left side turn signals work normally Right side turn signal - all lights flash including running lights With lights on - Left side works normally Right side nothing flashes lights are just on I have cleaned up/replaced grounds that had dicey connections and while all the lights are now brighter I still have the issue and I am running out of ideas as to where I should be looking for the failed ground wire. I would appreciate any ideas you all might have on where I should look/what I should attempt next.