Figuring out heater grid cycling...?

[dieselcruiserhead]

For those of us doing swaps, I don't have a Dodge so never learned how the heater grid works and the cycles it operates at...



On the 12 valves, I guess this is controlled by its own little box. Should I source this box or should I wire it up with a simple 12 volts and a push button and play by ear. . Also these are 4BTs, so they had no cold start assistance originally. . I did have to use ether a couple times and it, even with caution, it lead to head gasket failure...



The pump itself is a Bosch VE pump with an air temp sensor in the intake that will retard (I believe) the timing to assist with cold start. But that is it. Do early 6BTs have this too so are the cold air grid heaters compatible?



Thanks, if I get poor response I'll post in the Gen 1 section...









This is from the FAQ on the TDR page, that generally talks about the heater grid cycling...

We’re going to make an assumption that the lights dim/flutter shortly after start up of the truck. Or, you can get the flutter at a stop light when it is really cold outside (hence cold air into the engine). Having made those assumptions, the problem can be described as “normal. ” Do not spend efforts at the dealership to correct a “normal” truck characteristic. Thanks to writer, John Holmes, for the explanation (Issue 20, page 25). The following is the reasoning:



The Cummins uses a grid type intake air heater. Think of the intake manifold air heater as a powerful hair dryer grid. By design, the Diesel engine is a “heat” engine. For cold weather operation, the Cummins uses the grid heaters to warm the initial charge of air tot he cylinders. Never use starting fluid/ether to “help” your Cummins start. Use of such is asking for an explosion in your intake manifold. Ether has a flash point of 360o.

There are two cycles: the pre-heat and the post-heat cycles. When you turn the ignition switch on, and the temperature is 59o or below, the toasters come on for 10 seconds (down to 15o). If it is between 0o and 15o the “wait to start” light will stay on 15 seconds. If it is below zero, thereby freezing portions of a brass monkey, you will have to sit there for a full 30 seconds while the intake manifold rubs its hands and stomps its feet.



After the engine has been started, the post-heat cycle takes over. If the temperature is below 59o, the heaters are cycled on and off depending on air temperature and how quickly the Cummins gets toasty. You will notice the voltmeter acting like a windshield wiper as the heaters are cycled. Like man, they draw 120 amps! Thus, the light flutter as the battery is working to supply current to all circuits. This condition is normal. It occurs on all trucks manufactured from ’94 to current.

 

[DogDiesel]

Never hooked it up

My heater grid has never been hooked up on my 6BT chevy conversion. While in MD, on the Chesepeak Bay, it'd get into the minus Fah, and Oh, I'd have to plug it in overnight, but after that, it'd start fine all day.

If I did hook it up, I'd just use a manual switch to relay.

Also, I have a 6. 5 Marine Glow plug timer I bought from Peninsular Diesel that is adjustable from 8-60 seconds (@ $88. 00). Too easy to install. I could use that if I need a heater grid, too. Until the engine gets a little wear, it is not needed, mine starts fine.



IMHO: A lot of the 4BT starting problems are ring wear, and spiking starters drawing the ignition low and giving voltage droop. Heater grids would only be a band-aid till the real problem is fixed.

Wayne

 

[dieselcruiserhead]

this one starts and runs fine. Very little wear but in fact I am considering rebuilding it anyway while I have the motor out...



problem is, it gets real cold up here sometimes in northern utah in winter. . Sometimes even -16 to -20 below. Honestly the 4BT always did great with all of this even pretty cold temps, but at a certain point you need starting aid. Unfortunately, more often than not, I am in a place where I cant plug it in, so thats the problem. Also once in a while, I'll need to hop in it and go right away for a last minute appointment. . Had to sell my old benz because it was embarrassing sometimes because I couldn't make it sometimes because it wouldn't start "car trouble. "



Anyway, even if I did use the computer, I would probably still rig it so it only came on with a push button for cold mornings.



Also I am pretty good with wiring but am a little confused as to the unit itself and how to wire it up. It is from a '04 24 valve. What is the ground, the short cable that goes to the motor? Then there are two wires for looks like each grid, are they powered seperately for staggered cyling or more heat at some times versus less?

 

[DogDiesel]

Thick Oil

I normally run 15W-40 in my diesels, but when I live in cold winter temps, I drop to 10W-30 till spring.



Once, with one of my diesels I had 15W-40 that would not start at -8*F. Pulled the dipstick, and it was like grease. I drained the oil and put in 10W-30 and it started right up.



Wayne

 

[JLEONARD]

Should I source this box or should I wire it up with a simple 12 volts and a push button and play by ear. .

Do early 6BTs have this too so are the cold air grid heaters compatible?

This is what I would do. You'll need a big relay of course as these things draw a lot of juice. And you won't hurt the engine at all by using the grid heater... it simply warms the air going into the engine.

When the temps are above +20 F I don't bother waiting for the grids to cycle, I just crank over. Below +10 F the grids are pretty much necessary... yes my truck will start, but it's downright rude and takes a lot of cranking.

I would use about 10 seconds on the grids below +20 F, two cycles below 0, and judge the others temp ranges as you see fit.

Make sure you turn the grids OFF while turning the starter as you'll need the full power that's left for the starter.



And yes the older 6BTs have BOTH the grids and the KSB (timing advance) on the pump.

Hope this helps.

Jay





BTW... . I have an 89 "donor" truck ... if you need the relays or whatever send me a PM and we can "talk".

 

[dieselcruiserhead]

great thanks J. . Appreciated. . I may contact you about this. I do not doing the wiring /relays etc, and don't need stock, but if there is rhyme or reason to it then I may contact you for those parts...





I am going to do some more research on it. . As far as I can tell, there is a common ground that grounds via the motor. Fine enough. Then there are two hot 12 volt leads, one that is directly grounded that I figure get hotter quicker, and then there is one that appears to ground through the aluminum housing (probably at a measured resistance or some sort of lowered longer cooler rate) for post heating while driving??



If anyone has tips on this let me know. .



Thanks, Andre

 

[dieselcruiserhead]

here are some photos of the grid heater, you'll see what I mean about wiring and the two grounds...

 

[THeske]

It's the same ground

here are some photos of the grid heater, you'll see what I mean about wiring and the two grounds...

Don't confuse yourself about the ground, It's the same, the 2nd connection just isn't being used,

I'll run you throgh this if you want, I have a Cummins in my ford and I like the manual button for my grid heaters, The automatic cycling of the heaters are a pain in the butt anyway, ( harder on battery/alternator life ) after the motor is running the heaters cycle why tax the alternator/battery for no reason,

Anyway put the ground wire from the heaters to a good ground on the intake, The hot wires run to a heavy duty relay, or two ralays, (mine has just one ) A starter solenoid from a ford works just fine, Then run a hot wire from the battery to the relay/relays (use a min 4 gauge wire) from the relay signal terminal run a wire to a momentary switch in the cab ( 18/20 gauge wire ) from the other side of the momentary switch run a wire to a ignition controlled hot at the fuse panel (this is preffered but not nessary) Or just find a constant hot termination/ wire under the dash

Make sure you use a momentary switch or you run the risk of burning your heaters out if you forget it on

 

[KZimmermann]

I was thinking about using my Ford glow plug relay, it should be up to the task, right?

 

[Forrest Nearing]

if you've got good batteries, you shouln't need grids... if push comes to shove, a SMALL shot of ether should get you going. if I was doing a conversion, I'd just put them on a push button... try to start, if it doesn't light off, hold for 5 seconds, it should start



they're an emissions thing



I leave mine disconnected 99% of the time

 

[mazdarotary]

Hey guys,



I am looking into buying an 83 crew cab dodge with a cummins allready under the bonnet,and I have questions regarding the grid heaters. In my 92 D250 the heaters worked great,and I know this truck has the heaters,but the guy who has the truck,and did the conversion never bothered to hook them up(he lives in south Texas). I live in the North East,and would like them to work,but I don't have a donor truck to swap over the controls,and such. Can these be wired up easily with a little thought,or would I be best to find a donor at a bone yard,and swap the wiring over to this truck?By the way the donor was a 92 W250 from what I was told.



Chris

 

[dieselcruiserhead]

Yes I know they share the same ground. . My logic is that one has a good direct ground and the other has a 'via aluminum' ground similar to glow plugs that are wired with a metal band that provides resistance. Longer heating at lower voltage than 12 V. There are two bands of wires with two separate 12 volt feeds for something. I will use a momentary switch definitely and probably not start most of the time. .



What I am trying to figure out is which tab is which and for what. should I hook them both up at the same time for high, or does one cycle separate from the other for one reason or another? Will it burn out if they are both cranking away on high at the same time (seems like not?)



Also, I have used ether quite a bit with several different diesels. Also always very carefully, small busts, just enough to get the engine started, yet it still lead to power loss and eventually head gasket failure in the middle of a 28 hour trip with my B series... The old mercedes seemed fine with it though, glow plugs and all. . So, I will not ever use ether again and don't recommend it to anyone at all. .