1st Gen Intake Manifold Heater Operation And Diagnostics (Grid Heater)
 

This might help a few of y'all!

1st Gen Intake Manifold Heater

nice description:U::U:

there wouldnt happen to be a diagnostics chart in that fancy book ya got there? goin by what this description is tellin me my thermistor is checkin out ok; just no idea why no pre-heat event is occuring. to my knowledge it doesnt pre-heat even when icicles are forming on your nads. i understand the differences in years and i'm not 100% sure which set-up i have but if i wanted for it to pre-heat anyways would a module out of a 93 do the trick?

My 93 does not preheat all the time, only when it's really cold. Doesn't seem to be until the 2nd gens that they preheat no matter what

hmmm i'd like to get it so it does pre-heat anywhere below 54*.... doesnt have to cycle just pre-heat i like the rents grid system much better than mine... until the truck starts to cycle it likes to spit once or twice... its a holy hell when she gets to freezing temps spit sputter rattle... just tryin to make the old girl abit more stable lol

plug it in

wow. great info!

mine have never run for more than 5s or thereabouts so far... but it hasn't even been below 40f yet. then again I still seem to have a dead battery every morning lately :(

dead battery or the contacts on the starter are bad? i know my starter will sound like a dead battery let off the key and turn it again and it turns over like a brand new starter...

looked like a cell went bad.. sealed battery and a cap blew off
replaced with a good one, drives fine all day, let it sit overnight and after the grid runs it's flat *shrug* I must have a draw somewhere but dunno where yet.

it was pretty chilly this morning and the grids ran for about 10sec longest I ever saw em go. it's usually like 2-5sec. regardless. i'll have to read that manual page a bit better, should they still cycle after the motor starts? mine never have but any glow plugged truck I've had continued to cycle after start.

yeah ; it'll cycle for a little while after start-up; as mine doesnt pre-heat but cycles afterwards and from what i'm reading this seems to be normal.

Non-intercooled (89-91) with the wax motor KSB don't bring the heaters on prior to start (wait-to-start dash light) till around freezing. Later intercooled (91.5-93) 1st Gens preheat starting at 50 degrees. This is assuming the sensors are stock for that year and working correctly along with the rest of the system, PCM, relays, etc.

Makes me wonder about mine..

it ALWAYS preheats.. even when it was chillin in 95deg. temps

usually hear it click and have wait to start light for 2-5sec when it's warm and up to 10 so far when it's cold.

where is the temp sensor on a 93IC motor? guessing one of the 2 on the top of the intake?

Put it on a momentary switch in teh dash. Hold teh button for 5 seconds... Start the truck. Being momentary you cant leave it on by accident.

haha no thanks on the switch. when I first got my ford the glow controller was bad and my buddy said dont waste your money.. and added a switch. i proceded to burn them up in about 5sec and went out and bought the controller lol. I like the automatic stuff to work the way it should.

for that system; yes... amperage is way too high to use a plain switch, the cummins grid system uses two high amperage relays or probably better described as solenoids to control the current going to the heater. the momentary switch would just need to be wired to the control side of the relay; i actually thought of doing this with a 2 position switch and a certain value resistor. say switch up is normal operation, switch down signal runs through the resistor and fools the control module into thinking it's atleast 32* out. easy way to find this value would be with an ohm meter and a bowl of ice... let it chill to 32* and measure the resistance then find a resistor of that value... just my thoughts. but this does mean you'd have to flip the switch for normal operation after crank and start up as i assume the grid heater would continue to cycle constantly even at operation temp due to it still thinking the IAT is 32*; so momentary switch may be a slightly better idea and a little less involved

Right, the ford uses a 6v plug running of 12v to heat faster, off a solenoid as well.

I do have a degree in electronics. :U:

I'm gonna figure out which sensor i'm lookin for here and test it out.

sorry bud wasn't sayin ya didnt know anything; you told me that your kinda new to the cummins set-up and are more familiar with the fords. just makin sure there arent any grey areas is all :c:

I learn quick. haha

Alot of cummins run the grid off a momentary switch. Ford glow plugs burn out all teh time on the older trucks.

air heater
 

I have a 2002 5.9L with the air heater. It is drawing 100 amp. the post on one of the relays melted off. I think there is something wrong. Does anyone know what the amp draw should be? :humm:

I know its ALOT but I'm not sure...

After some looking its 110amps @12v, so you are in good shape there...

The load is so high that the belt on the alternator is slipping and making a lot of noise..... that is why I started looking for something wrong.. maybe I should look at the belt area.... Thank you for your help

my wait to start light does not come on at all when its cold but when its warm it does. i replaced the grid heater and still nothing. could it be a sensor? or maybe one of the solenoids? :humm:

Sounds like maybe somebody at some point installed the wrong sensor. They are different between I/C vs. non-I/C. That is the only thing I can imagine that would explain such backwards behavior. I say this because the KSB is electrically opposite in the I/C vs. non-I/C (hot/off) and also activates through one of those sensors.

ok so in the diagram there is are two wires that go into the ECM:
orange/black
yellow/black

I dont have the ECM from a dodge I did an engine swap and am trying to get mine working. can i just hook the two wires i listed above to a switch the links to the battery. and then just have it switched manually? also will it shut off on its own once the grid heater heats up?

You can wire it to a switch, use a momentary switch though so that it cuts off when you release it. I would just wire it straight to the relays.