Turn signal problems

[Pockets]

I have a 2001 Montana minivan and the driver's side rear turn signal is doing weird things. It doesn't blink properly, and sometimes the backup light sort of blinks with the rear bulbs. It seems to be an intermittent thing as well. When it decides to malfunction, both the little green turn signal arrows on the dash board will blink, too. I have examined the entire tail light assembly and found nothing wrong- no rust or corrosion. I have replaced the electronic module that controls the turn signal function. Anyone have any ideas? 

[Frosty]

Have you checked all the bulbs to see if one or more of the filaments are bad? I have had vehicles that will blink faster or louder when a bulb has failed or is about to fail. Check all the bulbs that blink from front to back on the driver's side. If it is a bad or failing bulb, it might not be in back but it is in the left hand turn signal circuit.

 

[Pockets]

Please, don't insult my intelligence or waste my time with answere like this- of course I've checked all the bulbs, even gone so far as to changing every bulb out for TESTED new ones. I need an answer from someone who has had this problem which probably involves a wiring fault, something that requires way more sophisticated diagnostics talent than a burned out bulb mentality. 

 

[Ringo64]

7 minutes ago, Pockets said:

Please, don't insult my intelligence or waste my time with answere like this- of course I've checked all the bulbs, even gone so far as to changing every bulb out for TESTED new ones. I need an answer from someone who has had this problem which probably involves a wiring fault, something that requires way more sophisticated diagnostics talent than a burned out bulb mentality. 

 

Calm down here, bud. We're all a friendly bunch and not insulting anyone. Have to start somewhere to know what's been done and where to go next. Frosty is one of the most knowledgeable people when it comes to cars and troubleshooting. Feel free to mention what you tried in the future

 

[TWO LANE BLACK TOP]

Had the same problem with a 03 Montana.. Awhile back..It's fixed now...

Edited May 3, 2017 by TWO LANE BLACK TOP

[Frosty]

OK next thing would be to completely remove the rear driver's side tail light assembly. Once you have that out, you should find a printed circuit board/bulb holder that the bulbs plug into. I would remove it completely, and disconnect the electrical connection. Once it is out, look for any corrosion or broken leads on the electrical connections or in the bulbs sockets themselves. Also inspect your tail light lens (since you have it off) for any cracks or damaged weather seal where water can get through.

If you find a lot of corrosion on this PC board, it may need to be replaced. Fortunately these parts are available.

If you find slight corrosion, then some sand paper should clean it up and then add some di-electric grease to help keep any moisture in the future out.

Edited May 3, 2017 by Frosty

[TWO LANE BLACK TOP]

I had the exact same problem on an 03 Montana..The PC board looked great no visual indication of an issue...Just replaced whole assembly...Problem solved.

[Frosty]

Thanks for the support Two Lane! 

If that doesn't work and assuming that we have no physical wire breaks or shorts in the system, then the last two things in order of cost/effort to repair is the turn signal switch in the steering column or the body control module (BCM). Either one may be to be replaced. Both are timing consuming to get to and not as cheap to replace as the PC board. Which is why I start with the cheap/easy stuff first.

Edited May 3, 2017 by Frosty