2nd Gen Non-Engine/Transmission park (marker) lamps flash 3 times?

[paulsmith]

I have a 96 3500 2wd. When I hook up a trailer (and sometimes even without the trailer) When I first turn on my headlights, ALL running lights on the truck and trailer will come on for 20 seconds, blink off for 1 second, back on for one second, then blink off for about 10 seconds, back on for about 5 seconds, the back off for about 10 seconds, then back on, and they stay on.



What the heck is this? This happens 9 out of ten times when I have a trailer hooked up, and the dash lights do not go out.



Turn the lights off and back on does not change anything. If the lights are "off" with the light switch on, I can push the headlight switch in, and pull it back out and the light will not come back on until the 10 second wait... .



I just repaced the 6 way plug as it was in bad shape, but this problem is still there.



The "trailer tow relay" controls the trailer lights, but it is not just the trailer lights, it is every light on the truck and trailer except the headlights (if they are turned on). I can pull the tow relay and the trailer lights go out, but the truck light stay on.



I took a 600 mile trip today: The abs/brake light came on. the running lights are doing this blinking crap, the Trans cooler lines are leaking now (those plastic connectors), the water pump is leaking water, (2 gallons in 100 miles) and I have oil dripping like crazy from somewhere up front.



BAD DAY!



Paul Smith

 

[y-knot]

Sounds like a relay problem, and it must be iratated by the additional load of the trailer lights.

 

[paulsmith]

But, this thing blinks three times every time, then works perfect after that. Shut the lights off for 2 minutes, and they will blink 3 times again, when you turn them back on. But so long as you leave them on, they stay on. Also, I was under the impression that the trailer running lights were completely seperate from the truck lights, and yet they all blink (only three times)... .

 

[KBennett]

Circuit breaker?

Is there an auto resetting circuit breaker in the light circuit? Most of the time these are thermally set and reset. The circuit could be overloaded and when the bulbs are cold there is a big inrush of current tripping the breaker. After a couple tries the bulbs warm up and do not create the inrush.



For a test try removing a couple bulbs from the circuit and see if the problem goes away or if the time between on and off changes.

 

[rashwor]

If it helps your feelings...

the electrical problem is the hardest to fix. I won't pretend to know anything about this.



The water pump is each to change... less than 30 minutes and no gaskets or sealants necessary. You can get a reman from Cummins for around $75 - 100 including $25 core charge shipped to your door.



The oil leak is probably on the vacuum pump / power steering pump. On my '92, it has been a pesky recurring problem.



Good luck.

 

[paulsmith]

Update:



I just had not noticed (I own a trailer sales, I ALWAYS have a trailer connected) But it flashes THREE TIMES even with out a trailer hooked up. Only 3 times, always 3 times. Takes about 2 minutes for the lights to stay on for good. This is the park lamps only, headlights stay on, dash lights stay on, and brake lights still work during the periods the other lights turn off... .

 

[KBennett]

Electrical problems are the hardest to locate but you always need to start at one end of the circuit and eliminate components until you find the problem.



I don't have a wiring diagram of your truck but in your case the power probably comes from the battery, through a fuse panel(where that pesky circuit breaker may be) then through the light switch and on to the bulb. At each point along the way there are lots of connections that need to be tested as well. Also, check to see if you have any fusible links in the circuit.



I wish I was still in the area to give you a hand. I lived in Glen Ellyn until 3 years ago and I miss Portillos! But I don't miss the Chicago winters.