Hey everybody,
I have noticed that on my 2 ctd's that as it gets colder, when you start them up and the headlights are on, that the voltmeter will momentarily drop a few volts and the headlights will dim. Then the voltmeter will jump back up to normal and the headlights will brighten up.It usually does this for about 5 mins or so. My Dad's 95' and my 04.5' and my 92' all do this same thing. Is it the regulator cycling or what? I was just curious and wondered if anybody else experiences this phenomena?! Thanks!!
ez

 

yeah mine does the same. I think it the heatergird on the intake preheat cycling. It only does it on days when the "wait to start" light comes on.

 

My wait to start light cycles the same amount of time regardless of the weather. Is it supposed to do that?
ez

 

the light only comes on before you start it, and should turn off after the engine starts. the light doesn't cycle, but i think the actual heater grid turning on and off is what dims the voltage. the light should only go on when its below 40 or so, at least thats when mine goes on.

 

That is what mine does. If i don't wait for it to go out and i start the truck, it does go out when it starts. Should you always wait for the WTS light to go out before you start it, does it hurt anything if you don't? Just wondering
ez

 

doesn't hurt anything, just might start a little harder if its real cold.

 

The charge-air heater(s) draw 220 amps when operating. You're stock/OEM alternator puts out 160 amps when at the right engine RPM.

Do the math . . . . ..

I can't recall the exact temperature (60*F ?), but when it's cooler outside, the heaters will cycle till the engine coolant temperature comes up. It's an emissions thing.

Many are concerned about it none the less and feel they must disconnect them. Their trucks run just fine albeit perhaps with a little initial white smoke.

The wait to start lamp allows the aforementioned charge-air heaters a chance to warm up correctly before you hit the starter.

 

Thanks BC. I wondered what was going on. Thanks for the help. And thanks feveree40 for the answer too. later guys
ez

 

Your stock ND alternator should be only 120 amps.
Jim

 

Oops! I must have been thinking of your upgraded alt Jim.