Voltage Drops

[JBurghard]

Lately with the on set of colder temps here in Colorado I have been experiencing some wierd Voltage Drops with my 93 CTD...



When she has sat in the cold for awhile where I cant plug in the block heater the Voltage of the truck is almost at the 8 on the display and after about 30 seconds I hear a loud click like a mechanical relay shutting and the Voltage jumps backup to the normal range.....



After this happens while I am driving I will see the Voltage drop then hear the same clicking noise and the voltage will return to normal. It will do this a couple more times until she is warmed up... .



The truck doesnt seem to do this if I have had the block heater pluged in or if its still warm from when I drove it last...



I would appreciate any help you can give...



Thanks



James

 

[BushWakr - RIP]

Hi James,



Go to bed, roll over and don't give it a second thought... .

What you are seeing is the proper functioning of the manifold heater relays and the heater element.

On initial key on, the temp sensor on the intake manifold tells the PCM that it's chilly out. Now, depending on the outside temps the "wait to start" light will come on, and you'll see the alt. gauge do a face plant... . after a bit you'll hear that heavy "clunk" which is the relays lettting go. The the alt. gauge will slowly climb. As soon as you start the truck, the heater will continue to cycle on/off, on/off until the intake air is around 90*F. At that point it should stop cycling. The duration of on time and off time will depend on the temps. . it can range from as little as 5 seconds to as long as 30 seconds under real cold temps.

Hey, bonus, the thing is working as planned... .



Pastor Bob...

 

[JBurghard]

Well thats good to hear... ... .



Usually when you see wierd things start to happen to your truck all you can see are $$$$$$$$$$$$$$$$$$$$... .



Thanks again.



James

 

[Greenleaf]

I have had difficulty in the past convincing my bus drivers that THIS IS NORMAL. Amp needle sweeps up to 15, volts drop to 10 and lights dim. It looks odd, but one of the peculiar aspects of these engines. Come to think of it, I wouldn't want it any other way. Glow plugs????? don't need no stinky glow plugs.



Greenleaf

 

[JLEONARD]

Yep... that is normal operation.

I am considering installing a switch so I can keep the heaters from cycling once I am up and running..... I hate putting all that extra load on the electrical system... ... especially bad when the wipers need to be on.

Any thoughts out there about doing this?

Jay

 

[JBurghard]

Thanks again for all the good input... ... .



First time acctually owning a Diesel so its kinda learn as you go.



Thanks



James

 

[skobylenski]

Well this is the place to learn! I've only been lurking around for short time - compared to some of these guys and gals - and I already know hundreds of new things. This is a great place - and if no one has said it already - WELCOME ABOARD!!



Scott

 

[dpuckett]

Hey, welcome aboard, JBurghard. Just wait till the BOMBing bug hits. I've just replaced my worn out H1C with a PDR HX35, and put a 12 cm housing on the hot side, and I already need MORE POWER. Hit 38 psi on the way home last night; and hauling my grandpa's Trooper to the shop yesterday, I kept getting into the red zone at 2/3 pedal, so intercooler will most likely be next thing.

At least your "wait to start" light comes on; I have to turn the radio off and listen over the buzzer to hear the click. PM me if you have any ideas on that- bulb is good. How's the weather out there? I miss the prairie. Fall is finally here. Was 70 two days ago... . callilng for 28 tonight.



Daniel

 

[BushWakr - RIP]

OH man,,,, I never heard such whining about a bit of cool weather... . heck up here in Canada, when winter comes we buy our fuel in large boxes with precut chunks of fuel in it.

Just pop em in your mouth, warm em up, and spit in the tank... . bunch a wussies... .....

Heck one time wildman Wilson forgot to spit and swallowed... he still aint right... if ya know what I mean...



Pastor Bob

Our Lady Of Acceleration Church.