Lights Dimming

[RGRAT1618]

When the engine is cold and for the first 10 15 mins it sound like my a/c compressor is kicking on and off repetedly. every ting it kicks on all my lights dim. This is happening with the a/c shut off. Any ideas of possible problems. Has been heard of before.





Rob

 

[Bob Wagner]

its getting chilly

its your grid heater cycling

 

[GBall]

My rig does the same thing but for about five mins. What does your volt gage say? I will show down to 12 volts then back up to 14 V keep changing every little bit. I think it is charging the battery back up after start up and heaters were on. Rember we have alot of amps going out for the start and heat mode. So we have got to get the juice back to the batterys fast. That is my 2c worth. But It does it every morning more so when it get cold outside.

 

[RGRAT1618]

MY VOLTAGE DROPS JUST BELOW 12 VOLTS AND COMES UP TO A LITTLE ABOVE 14VOLTS.

 

[redneckdr]

mine did that for the first time this am. also the first time i had to wait for it to heat --temp of 50 degrees. then the grid heaters cycle on and off for awhile while the engine warms up. that will cause the voltage to drop while they are on. should stop after the engine warms up some. nothing to worry about, unless continues after the engine has warmed up.

 

[HC]

Ah, the seasons are changing, winter is on the way...

(and with winter comes the grid heater posts)

10 to 15 minutes sounds like a long time - suggest you look for this in your owner's manual and actually time it to be sure your unit is functioning as described. I'd look it up for you, but different years may have slightly different features - for example, I know my grid heater shuts off above a certain speed...

 

[Bigsaint]

If you want to really see them in action, wire up a set of LED's to the grid heater terminals. Not my idea, D. Dressler passed the info (and the LED's, thanks again David !!!) to me. When you key on and the wait to start light is on, both grid heaters are on. Once the wait to start light is out and you fire her up, both grid heaters are then acitvated for a moment then they alternate back and forth to each other until you either drive beyond 18-20 MPH (guessing at the exact speed here) or the temp. comes up. Those heaters draw some amps. , even drag the Mallory down about 1 psi when they are on. Like I stated, mine were given to me, but I would imagine that you could pick a set of LED's up pretty cheap at any electronics store, inexpensive BOMB that fun to watch. You will see them on whenever the outside temps. drop below 60F and the truck has been sitting cold for a while.



Scott W.

 

[redneckdr]

owner's manual

my owner's manual for my 01. 5 says the grid heaters cycle for ONLY 180 seconds. it doesn't say anything about speed. also, it says to let the truck run 3 minutes (180 sec), at fast idle, before starting to drive. guess i might get the flash for high idle speed after all. i hadn't planned to mess with it here in georgia. i started driving soon after starting--my driveway is 1 mile long, downhill--and the grids cycled for about the right time, then stopped.

herb

 

[JMoglia]

IT don't get real cold around here but when it does I just plug my heater into a coffee pot timer and set it for about 2hrs. before I get up, they do really work well,

just my . 02 JDM JOE

 

[illflem]

Herb, not sure on a 24 valve but on a 12 the grid heaters shut off if you exceed 15mph.

 

[mbrolin]

Redneckdr,the heater grids will stay on for up to 180 seconds depending on the ambient air temp. They will also cycle on and off during the initial engine startup and will shutoff above 18 mph. They can also cycle on and off while sitting at a stop light or driveup window even after the engine is warm. This only occurs in areas with extremely low temps. Guess I better get my timer setup for my block heater. Winter is coming.