grid heater reprogramming

[AH64ID]

This sounds like one is trying to fix a problem that doesn't exist. There are possibly millions of trucks running around with grid heaters turning on when the ECM thinks they should.

Yes there are lots of trucks running 100% stock grid heaters.

I look at it another way. The stock programming does work fine but it does run the grids excessively. Cummins states the ISB doesn't need any starting aids above 10°F and considers the grid heater on the Ram to be a starting aid. So why does it work up to 66°F IAT? Emissions.

While it is easy enough to just bypass the grid heater with the key or button I have access to the pre-heat table in tuning so I adjust it. I stop all grid pre-heat above freezing and really don't put any decent time into it until around 15°F. I also disable the heat while cranking that's active in the stock tune, this does cause faster cranking in the cold.

It's not something that is worth spending any extra money on, but if you're getting a tune already may as well reduce the unnecessary strain on the batteries and alternator.

 

[Prairie Dog]

Grids arent just a starting aid. They help with emissions and creating a more complete burn - which is better for your cold eng.

 

[AH64ID]

Grids arent just a starting aid. They help with emissions and creating a more complete burn - which is better for your cold eng.

IMO, Above 20°F it’s just emissions.

Almost all of the cold engine combustion aid is the post-heat cycle, which I’m not able to edit so it still works stock. I would likely kill it above 30° thou, it’s a lot of strain on the alternator..especially the 136A that is on the 3rd gen trucks. I’ve ran without a great heater for a couple winters and above 20° I couldn’t see any difference without it. It would start a hair quicker with it below 20° and a lot quicker below 0°. The idle started to get rough below -10°F without the post-heat cycle. It did start and idle at -25°F one morning without the grid heater but she really didn’t like that.

I saw zero performance gains with the grid heater removed so after a couple summers of testing, and one winter, it stayed in year round.

 

[Axekicker]

First question how do you know the grid heater was actually cycling? 60 degrees is on the borderline that it might cycle once or twice but as soon as you exceed 15 mph the grid heaters cut out. If it was actually cycling driving there is another issue somewhere.

Cerb: I know it's the 'grids' cycling because I have two volt-meters atop my steering column...one wired direct to each Cat battery. When the grids kick-on it pulls both meters down from 14.8 volts to 11.5 volts...then when the grids turn 'off' both meters go back up to 14.8 (and the cab lights dim...and the gauge cluster volt-meter mirrors what the other 2 meters do etc etc...)

 

[Axekicker]

With UDC Pro tuning on a Touch or MM3 the grid heater can be adjusted. I do it on every custom tune I write.

AAaaahhhhh! That's the answer I was looking for. Rob is writing/editing my MM3 'tunes' so I'll have him move the grid-cycle temps down. Thanks AH64ID !!!!

 

[KATOOM]

Just curious why you have two volt gauges... Batteries which are tied together will always read exactly the same even if one is bad. And the weaker battery will always win what the voltage level is too. One gauge will tell you everything you need to know.

 

[Axekicker]

Just curious why you have two volt gauges... Batteries which are tied together will always read exactly the same even if one is bad. And the weaker battery will always win what the voltage level is too. One gauge will tell you everything you need to know.

In 'theory' that is correct...but I do see 'small' voltage differences between the two in 'real-time' when the truck is running. I just put in two new 'Cat' batteries to replace the 2 year old Costco's that were causing problems because one developed a dead-cell. I saw wider voltage differences between the good Costco battery and the bad one, prior to the swap-out. It's also why I carry 3 different voltage-analyzers at work (inspector). I never trust 'one' gauge, tester, analyzer or meter. Redundancy is a time-saver and in some instances....expedites problem-solving.

 

[brods]

A couple decades or so ago there was a guy by the name of Harold or Harvey (cant remember) who built in his garage, and sold through the diesel forums, a wiring device he called the "grid heater saver", which disabled the grid heaters when the engine coolant was above set coolant temperature. It prevented the constant re-cycling of the grid heaters when you're making frequent stops around town driving where you're shutting the motor off and re-start the engine.
I've tried to find out if anyone has one to possibly replicate, because the Harold/Harvey guy is nowhere to be found anymore...

There had to be more to it that ECT. The grids fire based on intake manifold temp. On a warm engine the IAT goes up when you shut it off running errands, not down. That makes the grids less likely to be used for in town driving, even in cold cold weather.

Edited to stop hidden quote, stoopid new forum software...

There had to be more to it that ECT. The grids fire based on intake manifold temp. On a warm engine the IAT goes up when you shut it off running errands, not down. That makes the grids less likely to be used for in town driving, even in cold cold weather.

Why not just block them based on ECT? I notice the same issue Katoom describes at drive up windows in the winter. If I stop for coffee on the way in to work, the truck is warm, it gets shut down during the order and restarted to pull forward. The grid heaters cycle which causes the engine to load up so it sounds like I'm impatiently blipping the throttle. It is annoying and, as you point out, it is needlessly and wastefully putting a load on parts.

 

[AH64ID]

Edited to stop hidden quote, stoopid new forum software... Why not just block them based on ECT? I notice the same issue Katoom describes at drive up windows in the winter. If I stop for coffee on the way in to work, the truck is warm, it gets shut down during the order and restarted to pull forward. The grid heaters cycle which causes the engine to load up so it sounds like I'm impatiently blipping the throttle. It is annoying and, as you point out, it is needlessly and wastefully putting a load on parts.

That’s the post-heat cycle and it uses other info that the pre-heat, but I don’t ever recall it working on a warm engine.

 

[KATOOM]

That’s the post-heat cycle and it uses other info that the pre-heat, but I don’t ever recall it working on a warm engine.

Yes, thats exactly what it does and is why that guy created the "grid heater saver". As you pointed out, in theory the grid heater shouldn't cycle when a restarted engine is still within the normal range of coolant heat, but it does. The grids obviously dont cycle nearly as long either because everything is warm and toasty already, (or until you hit 17mph) but its just stupid and annoying and places an unnecessary load on the entire charging system.

 

[brods]

Even with the high tech cardboard winter front and coolant gauge reading just below 200F it cycles the grids after starting. It kept cycling them, with the resultant blip to the throttle when the alternator loads the engine, until I pulled away from the drive up. OAT was around 34F. If they stopped cycling at 15 mph or kept going for a while there would be no way to hear. The stock volt gauge is a joke, so no help there. (If it is even real, it is severely dampened which makes its usefulness questionable).

A coolant temp switch blocking all grid heater function unless the coolant is cold sure sounds like the way to go. If my truck wasn't the next minor failure away from the scrap yard, I'd consider doing something about it....

 

[BigPapa]

That’s the post-heat cycle and it uses other info that the pre-heat, but I don’t ever recall it working on a warm engine.

My '98 does it, too. Every morning I get off the interstate from a 30 mile run, definitely warmed up, stop at the drive thru for a sausage and biscuit, and until I pull away and hit 15mph they cycle. I'd say the cycle is basically the same amount of time as a cold start.

 

[Axekicker]

.......If they stopped cycling at 15 mph or kept going for a while there would be no way to hear. The stock volt gauge is a joke, so no help there. (If it is even real, it is severely dampened which makes its usefulness questionable).....

That's another reason I like the two real-time volt-meters installed atop my steering column (see photo above). They stay right with the alternator even when the dash volt-gauge doesn't move. The MM3 I run, also shows real-time voltage at the ECM. That gives me a four point reference for system voltage (1=dash gauge cluster volt meter, 2+3=dual volt meters on steering column 4=MM3 box reading ECM voltage).

 

[Axekicker]

Here's a couple of youtube videos showing the heater-grids pulling voltage down during a cold-start.
and

 

[Mhennessy]

AAaaahhhhh! That's the answer I was looking for. Rob is writing/editing my MM3 'tunes' so I'll have him move the grid-cycle temps down. Thanks AH64ID !!!!

Update bump.
Was Rob able to write tunes to lower the grid heater activation temp down?
Thanks.

 

[Axekicker]

He said he did, but I saw no difference 'operationally'. Since my last post, my GH fusible-links melted one day while I was driving around town and the smoke started to roll out from under the hood, so I pulled over, grabbed my bull-nose nippers and cut both cables off at the battery connections and down by the relays. Problem solved. I don't get any codes and the grid-heater doesn't operate any more. Since it never gets that cold in Vegas, I just run without it. No more 'cycling' issues...at any temperature...hasn't affected morning start-ups...and it's not throwing any codes that show up on my MM3. AH64ID sent me a tune but I have not installed it yet...and he's got the lower GH set-point in his tune, but since my grid-heaters are DOA, I won't be able to comment on how well it works, until/unless I decide to reconnect them with new fusible-links.

 

[Mhennessy]

Thanks for the reply good sir.
How are you liking Robs tunes? I like them but do notice a bit of possibly "timing rattle" when running them. It is the worst on the MPG tune. I have not hit him up about it and maybe its normal with the tunes but it just sound like marbles in the 1600-1900 RPM range.
My truck is down due to a blown diff (hit debris on the freeway) when its back together I will touch base with him about it.

 

[Axekicker]

Rob's Cummins-tunes work well but I especially like his transmission-tunes. Rob is great to work with and if you tell him what issues you're having he'll tweak it for you. The 'rattle' is not normal in my experience. I used to get that on the high HP tune when I ran a Quadzilla box many years ago. I don't get any 'rattle' with any of Rob's tunes.

 

[AH64ID]

I strive for no rattle in my tunes too.

Wanna talk about rattle, stock 05 tune with 03 pistons and BBI stage 1’s... yikes!

Generally rattle can be fixed by reducing timing and/or rail pressure, usually pressure.

 

[Mhennessy]

AxleKicker,
I am running a similar set up as you with the 04.5 year BBI .5 and MM3 tuning. The only thing that may be different is that my sticks are the early 144 pattern and not the late 124 patter. Interesting you do not have any rattle.

AH64ID,
Interesting about the stock tune and stage 1's. Can you shed light on why that is? too much fuel?
When I run the stock tune on my 04.5 and .5 there is no rattle but when I hit the tunes I get it. Worse on the MPG and less on the street tune. I would think it would be the other way around on the tunes but that shows my lack of knowledge in that area.

Thanks guys and sorry to highjack this old thread.