Possible TSB 18-037-04 problem

[Cohomojo]

I've been noticing since I had the TSB performed, that my lights will dim for a few seconds, then come back to full strength. This goes on and on while the truck is warming up/idiling. I only notice this when I first start up, but last night after driving for 30 miles or so, when I parked in the driveway and let the truck idle, it was doing it again. It's weird, the lights are kind of surging! Going dim, then bright (normal) back to dim and back to normal.

Called the Dodge dealer this morning and after talking with the service manager, he said that there was another truck in the shop experiencing the same problems. He was glad I mentioned that I had had the TSB 18-037-04 installed because the other guy had just recently had it installed, and their thinking it might have been caused by the TSB???

Who knows, I'm supposed to call back in a couple days after they troubleshoot his truck and figure out what's causing the problem.

I'm wondering if anyone out there has been noticiing this same problem with their trucks after the installed TSB????

 

[sag2]

It is the grid heaters cycling. Your profile does not say where you are from, but if it was cold (very cold) outside, the heaters can still cycle if the engine is warm and you are idling.

 

[Cohomojo]

I guess my question would have to be, 1) why did it continue to surge after 30 miles of driving and the truck was warmed up and 2) it only started after the TSB was performed. It just be a coincedence.

I live in Northwest Washington state and the temp has only been below 32 once in the last 10 months.

 

[RKane]

My 4. 5 3500 does that. I have only had the oil changed, and the door moulding replaced, so I don't think I've had any other TSB's done. My truck does it in Portland, and it has only been at 40 or below in the mornings.

 

[PJ]

Same problem here in Grants Pass Oregon. 30 degrees +-

I would say it is normal as all my other Dodges have done it.

 

[CBrittan]

Is it possible that this 'light dimming' problem could be caused at idle when the engine is warm because the idle speed is less than required to excite the alternator adequately?



I expect the lights to dim when the engine is cold because we all know that the intake air heaters pulll more power than the alternator can produce at cold engine idle speed.

 

[ceaman]

i had that happen on my 03... never found a soulution... never became a problem

 

[SleeStack]

Completely normal. Mine did it before the flash and after.

 

[rotts4u]

My 04. 5 is also doing this both with and without my box in the circuit. Again only when cold. I put a VOM on it and could clearly see the voltage dropping when it hits the low point in the surge.



I guess we could connect a booster/charger to the battery and watch it to see if it is truely the grid heaters pulling so much current to cause the voltage drop.



What I dont know now is wheather the low voltage causes the engine to surge OR the grid heaters pulling away juice and causing it.



Don

 

[bpenrod]

Just watch the volt guage in the dash, when the grid heater turns on the voltage will drop to around 10 or so if I remember right. Thats when the lights dim, when the volt guage heads back up to around 14. 5 the lights will get bright again.

 

[rotts4u]

My volt gauge doesnt move when it happend. The VOM drops down to 13. 2 or so volts at the time of the studder. Then back to 14. 5volts



don

 

[JKing]

The grid heater work off of the ambient air temperature signal and cycle when below a certain speed (18 mph?). It's normal.

 

[lschultz]

Coincedence normal don't worry about it. When them grid heaters come on they pull some volts guage drops. When they go off guage comes back up to normal. There are several things that make them cycle-coolant temp,outside air temp and don't remember the other one. It don't get as cold down here as where you fellows are at but I have been stopped fueling up and they will start to cycle if the temp is cold enough. The older ones use to not do it but they got more sensors and things on these new ones.

 

[macdaddy]

My 99 as well as my 05 do the same thing and at much higher temps(55 degrees and lower) it is normal. I know on the 2nd gens if the temp sensor under the hood are 59. 5 or lower the heating grid will cycle on regardless of the coolant temp. I'm not quite sure of the 3rd gen trucks temp set point is, but it is very close.



05 3500 4X4 Laramie 325/610 6spd 4:10's new 10/30/04

Sold 99 3500 4X4 SLT Laramie ATS trans w/TC,VB comander and a 53 under the hood :{

 

[DGFoster]

This is normal. .

 

[rashwor]

It is normal grid heater cycling.



I will say that on my '05, the volt meter in the dash did not move when the grids were cycling the other morning. It set steady until the cycling finished at about 12 volts and then returned to about 14. 5 volts. In my '92 and '99, the volt gauge in the dash moved up and down corresponding with the cycling of the grid heaters. I wonder on the '05s if DC set the volt meter gauge to "meet customer expectations" like the oil pressure gauge on late second gens and 3rd gens?

 

[Cohomojo]

Thanks for all the replies. I'll ck the gauges tomorrow morning and see what happens. I'll also call the Dodge dealer and let him know about the information I gathered from this post and see what he says.

 

[EEdmondson]

The voltmeter is a fake. It gets it's input from the computer and doesn't follow the battery voltage. I guess the designers don't think that we can handle an erratic reading. It's my understanding, the grid heaters draw a lot more current than the alternator can produce. That's one reason we have 2 big batteries in reserve. This has been discussed before in case anyone wants to search.

 

[TFerring]

I have had the same "surge" problem when my truck is really cold. Headlights, dash lights and the blower motor all seem to surge when the truck has sat and is really cold. Just one more thing I have to have them look at when I take the beast in... .

 

[EEdmondson]

It's Not A Problem!!!!!