grid heater by i.s.x.

[KOYOTE]

http://forum.mopar1973man.com/showthread.php/1278-Switched-Grid-Heater?highlight=switch+grid+heater that is sweet and i was curious if anybody ever did try it on 2000-02 and if it threw the check engine light. i really have no need for the grid heater in my neck of the woods and my remote start system waits for the wait to start light to turn off so this modification might be right up my alley. thanks.

[ISX]

I *think* I looked and there isn't even an error code for it on the 24V. I only have 20 error codes to choose from so I knew I wouldn't have an issue lol. Mike takes the leads off the grid heater itself and I don't think he gets any codes doing that. Quick way to check is just go out and pull the little wires off of them and see what happens, worst that could happen is it throws a code.. If it doesn't throw a code and it's under 60F then you should notice that the volt gauge doesn't drop since the grids won't turn on.

[Mopar1973Man]

If you remove the positive lead from the battery your fine... But if you disconnect the solenoids (smaller wires) then it will toss a error code (P0380 and P0382)

[ISX]

Hmm, well there you go. Wonder why it throws a code. Gotta be a simple way to get around that.

[KOYOTE]

sounds like a winner to me, ill ****** the leads off tommorrow and see. i dont really see a need for the grid heater in mississippi although my buddy has a powerstroke and his MUST be plugged in in the winter down here and i use every opportunity i can to make fun of his ive even went as far as to mail him a glow plug when he calls and complains. thats money well spent!!!

[ISX]

Mississippi? Take the whole grid heater out Or just take the leads off like Mike does. Not sure what he does with them, wrap them in black tape maybe, or take them off from there and the relay and throw them in the garage

[Mopar1973Man]

I just unhook then and roll it over against the battery no tape or nothing... It only 2 heavy black lead on the postivie cable. Then you don't have to wait for the light just fire it up and run. I run my truck down to 30*F without grid heaters...

[LiveOak]

I see the grid heates in a different light. They are there to aid in the start and warm up of the engine in cold ambient temps. as well as aid in the cleaner combustion of the fuel until full operating temp is reached. If the constant cycling of the grid heaters is an issue on cold starts in the mornings, do like I do and plug the block heater in a few hours prior to start. I put the extension cord into an electric timer rated at 1850 watts and set it for 4 hours before the wife takes off for work. This warms the engine up enough so the IAT sensor senses above 60 degrees and no grid heaters. If you don't have outside power, then that is a personal preference call. The Cummins engineer designed the grid heaters into the ISB for a reason. They are not just for a cold start aid. They continue to cycle on and off until the IAT sensor senses above 60 degrees. This is what I have been doing with my truck and I am STILL running on the ORIGINAL OEM batteries. (knocking on wood)

[Mopar1973Man]

Well there is a catch to grid heaters too... Remember with them hitting on a cold morning they draw more than the alternator can use. So like this morning low is 55*F and if I was to have a fire call like I use to then I would fire up and drive 3/4 of mile and shut down... This is not enough time to recharge the batteries. So I've had a few weak starts... Like I know there is no reason or need for a gridheater on 55*F morning but the ECM is going to cycle it... Another flaw found... It not all based on IAT temp for grid heaters either. Its also based off the battery temp sensor too. So lets say 20*F you wait for the light fire up and cruise the to town say 20 miles engine is completely warmed up and 195*F worth of coolant. Now you stop at a local stoe to grab a pepsi or something and dart back out. The grid will run again even though the IAT is like 120*F from heat soak but the battery sensor is much lower... So since I live is a area where I bounce back and forth across the grid heater boundary I tend to just unplug them. Also if you do a lot of short trips 1-5 miles your batteries just won't charge up after being drawn down for 190 Amps...

[LiveOak]

Well there is a catch to grid heaters too... Remember with them hitting on a cold morning they draw more than the alternator can use. So like this morning low is 55*F and if I was to have a fire call like I use to then I would fire up and drive 3/4 of mile and shut down... This is not enough time to recharge the batteries. So I've had a few weak starts... Like I know there is no reason or need for a gridheater on 55*F morning but the ECM is going to cycle it...

Another flaw found... It not all based on IAT temp for grid heaters either. Its also based off the battery temp sensor too. So lets say 20*F you wait for the light fire up and cruise the to town say 20 miles engine is completely warmed up and 195*F worth of coolant. Now you stop at a local stoe to grab a pepsi or something and dart back out. The grid will run again even though the IAT is like 120*F from heat soak but the battery sensor is much lower...

So since I live is a area where I bounce back and forth across the grid heater boundary I tend to just unplug them. Also if you do a lot of short trips 1-5 miles your batteries just won't charge up after being drawn down for 190 Amps...

I am gonna have to research it to be sure as my memory SUCKS......but I think the grid heaters are also tied in the CTM relay that sets the STUPID door locks and also locks out the grid heater above a predetermined speed. The exact speed, I am not sure just yet but I believe is it approx. 13-15 mph.

I am gonna have to look this up and get back to you. I still think it is a bad idea to disconnect the grid heaters.

--- Update to the previous post...

The link below covers what my crappy memory was getting at:

http://dodgeram.org/tech/dsl/troubleshooting/Maniford_htr.htm

So the grid heaters are not working all the time even if the IAT senses below 60 degrees. Once you begin driving and exceed approx. 15 mph. The grid heaters are disabled.

[ISX]

Mine drops the grids at 20mph. As for disconnecting them, I turn them back on under 60F for the same reason LiveOak mentioned, they are there to help. Mike doesn't use his down to 30F because it starts right up, but let me tell you all a story.When I got my truck and went through the first winter, it would start up on the first crank with no smoke at 0F WITHOUT waiting for the grids. So why have the grids hooked up at all! The reason is that the engine is battling the cold and it is very hard on it. A year later, I had to use the grids on the same 0F day to get it to fire up the first [or even straying onto the second] crank. Moral of the story, use them! The main reason I put a switch in there was that at drive through windows or anything that didn't require much time, the grids would cycle again, which was not necessary since the whole thing is 190F. It does help the batteries out too. As for them being a battery killer, I doubt it hurts them at all. They charge back up when your driving and the big load from the grids knocks all the crap off the plates in the battery. LiveOak having OEM batteries is a testament to this. Short trips are what kills batteries, though it would have to be continuous short trips without EVER having a long trip. I drive across the street 4 times a day all week, and my batteries never notice it. The only time they recharge is on my 90 mile drive home. I do have 4 batteries though. They say 100% charge is 12.65V and after the residual voltage wears off, my batteries sit right at 12.65. To make it even more interesting, I even have 2 lead acids of different brands and capacities, and 2 dry cell optima red tops, all hooked into each other. Everyone says you can't do that, but I have yet to see a problem after it being like this for 2 years. The only issues are when one battery is dead, as it will kill all the others.

[Mopar1973Man]

I must be the only odd duck in the group that ditches the grid heater for the summer months... Typically I do hook them back up in the fall of the year when morning temps are as low as 40*F then I hook them up.. But while back I was doing alot of short trips and sometimes now I still do...

I'm also got my stock batteries as well and they are getting weaker... Sitting at 12.5 V after sitting all night.. I might sqeak 9 years out of them but I think this winter is going to be the end of them...

--- Update to the previous post...

Ummm...

Feeling so guilty about this I hooked mine back up..

[KOYOTE]

i dont suffer from guilt issues i pulled mine off today and hit remote start and she fired right up no waiting on wait to start, no codes either mine will stay off unless i have to head north but i dont see that for happening anytime soon

[jncornett]

I must be the only odd duck in the group that ditches the grid heater for the summer months... Typically I do hook them back up in the fall of the year when morning temps are as low as 40*F then I hook them up.. But while back I was doing alot of short trips and sometimes now I still do...

I'm also got my stock batteries as well and they are getting weaker... Sitting at 12.5 V after sitting all night.. I might sqeak 9 years out of them but I think this winter is going to be the end of them...

--- Update to the previous post...

Ummm...

Feeling so guilty about this I hooked mine back up..

Lol mine have been unhooked since i got the truck on the road last feb... grid relays are sticking on...and i still havnt replaced them or decided if im gonna hookem up... I thought i might just wait and see what happens.. mild winters here usually in the 20's some days in the upper teens but not many...

[Mopar1973Man]

Funny part in the last few day our morning temps have fell down to 40-45*F in the morning... (Can you say fall is here!?!?)

[AH64ID]

Yeah we have had some cool mornings too.. Really makes me love my little Man Wagon Jetta, with an alum 4-cyl and heated seats!! I can be sweating in the Jetta 4 miles before I stop shivering in the Dodge.As a gadget geek I am doing some reading on how to hook this up in my 3rd gen without a light. I really don't know when I would use the "ON" position, but I would use the "OFF" position quite a bit. Figure it will save wear and tear on the heater, alternator, and batteries.

[jncornett]

Yeah we have had some cool mornings too.. Really makes me love my little Man Wagon Jetta, with an alum 4-cyl and heated seats!! I can be sweating in the Jetta 4 miles before I stop shivering in the Dodge. As a gadget geek I am doing some reading on how to hook this up in my 3rd gen without a light. I really don't know when I would use the "ON" position, but I would use the "OFF" position quite a bit. Figure it will save wear and tear on the heater, alternator, and batteries.

I guess if all else fails you could run a switched relay and use resistors to mimic the grid heater coil load for the ecm ... run the factory signal wire through n/c contacts and use supply voltage on one side of a n/o contact and a resistor and the signal wire going back to the ecm on the other and let the ecm operate as it would normally... the wait to start would still come on but not actuate the grid relay..unless the switch was off... Feel free to correct my thought process if ive missed something

[AH64ID]

That's essentially what I am thinking. I am reading on the deletes, and will incorporate that logic.