Engine/Transmission (1994 - 1998) winter is a comin

[edgeman]

you know what that means COLD weather. Last year i put a post on here about my truck not starting and was never able to figure it out, once it got warmer the truck started fine. So since i havnt got it fixed i probably should start looking at it right now. Im thinking that it is a grid heater problem but am not sure. im wondering where the grid heater relay is (im guessing it has one) and other things i can do to trouble shoot. just to let you know what the truck is doing when cranking, blowing white smoke, smells like fuel, and fires then dies or kinda sputtering. Any help would be great. thanks

 

[The patriot]

Mine is a 98 but....

My grid stuff is on the drivers side fender. If you go over the battery then look straight down youre in the area. You should see 2 relays & wires.

 

[fest3er]

I daresay your grid heater ain't workin'. This should get you started on troubleshooting the problem.



In short, get an volt-/ohm-meter and verify the circuits.



In detail, using my '98 wiring as a reference (your wiring may use different colors):

• fuse #9 (side of the dash by the driver's door) should have +12VDC when the key is turned on.
• One of the control posts on each relay should have +12VDC when the key is on. These are LG/BK (light green/black)
• The other control post should be grounded when the PCM activates the relays. These are yellow/black (YL/BK) and orange/black (OR/BK). The PCM might control each relay separately.
• One of the large posts on each relay should always have +12VDC direct from the battery.
• The other large post should have a short circuit to the heater posts on the intake manifold (very nearly zero ohms in practice).
• Each grid heater should show somewhere around 0. 1 to 0. 15 ohms between the manifold lug and ground. Failure is indicated by an open circuit (infinite resistance).
• You should have a short circuit between the engine block and the batteries' negative posts (again very nearly zero ohms).

If things aren't good, you may have to trace the wiring through various junction blocks and connectors.



If all looks good, you can manually operate the relays by connecting the YL/BK or OR/BK control post to ground (negative) and momentarily connecting jumpering the other control lead (LG/BK) to +12VDC. You should hear and feel the relay click if it is working properly, and you should see the battery voltage drop significantly if the heater is working. You can test the heater by using a good jumper cable between the battery's POS post to the heater post on the manifold; use caution to avoid shorts and sparks and to avoid damaging the threads on the manifold post. Connect the volt meter to either battery and look for the voltage to drop significantly when the heater is powered up; you should even get a decent spark when you make the connection.



If the relays are bad, you can replace them with an OEM unit for $150 or so, or you can replace them with better relays; see http://murent.us/dodge-heater-relay/.



Keep us posted.

 

[Vaughn MacKenzie]

I'm just glad I live where I don't need grid heaters. . . unless we get a nasty cold snap and it gets down close to 0

 

[The patriot]

My grids did the opposite last winter. They stayed on.

I disconnected them from the battery.

 

[edgeman]

ya up here in the U. P. it gets cold. i will look for the relays and see what i find thanks for the info so far, its a lot of help.

 

[Skydiver]

Lets talk about grids. I disconnected my grids about 8 years ago and have started my cold soaked engine at 19 degrees F. Is it true that on some apps the Cummins 5. 9 bt does not even have grids? Such as a generator or marine app? I have been told more than once the grids are for polution control because the engine smokes bad for 1 minute when cranked below 45 degrees.

I always press the go pedal 1/2 inch when starting. Diesels need extra fuel for a quick start.

edgeman are you sure the engine is getting plenty of fuel? I know the grids does help mine start faster, but after they stayed on for 4 different time I no more. The grids over tax the alternator.

 

[fest3er]

Seven years now since I replaced the OEM relays with solid Stancor units. They're working as well today as they did when I installed them. Nary a flicker, never a hesitation. Always "tik, tik" when the PCM turns them on and "tuk, tuk" when the PCM turns them off. Compare that with the 6-18 month lifespan for the OEM relays.

I prefer having working relays because the engine warms up faster with them. The faster the engine warms up, the sooner raw fuel stops condensing on the cylinders and washing the oil off.

And 19F is actually rather warm for a Cummins. You get into -10F to -20F temps and you'll wish you had those heaters.

 

[Skydiver]

I do agree fest3er. And 19F is not real cold. Y'all can have it. I heard that as much as 1/2 of a mans paycheck goes to heating the home in the winter.

 

[edgeman]

i am sure now. about 3 weeks ago i changed the rubber hoses behind the manifold because the things were spraying fuel everywhere. so as far as an air leak i dont think that i the issue, i am pretty sure i am getting enough fuel. but what is puzzleing me is when it is 40deg or more the thing starts fine no probs what so ever, now when it get below that it cranks, and cranks and blows white smoke. i am also give it pedal when cranking. just wierd.

 

[CRWilliams]

I agree, it is most likely a grid heater relay. I had a bad one last year and my truck didn't like to stay running after the first fire. It would kick and then die. If it was really cold it might do it 2 or 3 times, but would then run rough with white smoke for a minute or two. I replaced the bad relay and it was much better.

 

[edgeman]

i think my problems have been solved. i will check the relays and replace if nessesary.

 

[nutter3]

https://www.turbodieselregister.com...484-stanco-relay-fix-failed-heater-grids.html

This should get you fixed up. It worked well for me

 

[edgeman]

cool thanks for the website nutter3 i will be checking it out very soon.

 

[edgeman]

on my volt meeter on the truck when i turn the key i don not hear any clicks and the meeter drops slightly in voltage. and when i say slightly i mean maybe a couple volts. deffinetly not what my dads does. this is telling me that maybe one of my relays is working. what should the meeter read when truck is cold and the key is turned.

 

[EKlem]

edgeman, the voltage depends on how your batteries are doing(which is somewhat related to temp) as well as how much load is on them. The best way to check the grids is to use a voltmeter and check each one to ground while the wait to start light is on. You can access them right at the intake horn.

 

[DavidC]

The best way to check is with a amp meter. I forget what the rating if the heaters are but your everyday meter only reads up to 10 amps and will not work. The alternative to a high amp meter is to check the voltage at the heaters then turn everything off and disconnect the wires on the grid and use an ohmmeter to make sure the elements in the grid are not burned out. I think sears carries a good clamp on ohmmeter that goes to 300 or 600 amp DC.



Dave

 

[edgeman]

thanks i think that one of the relays isnt working. i just order two new ones from allied electronics (100amp countinious). i do not have a volt/ohmeter. i dont know how pricey they are but i dont really have a lot extra to spend but will if it is nessecary. being that the grids almost dont go bad i cant think what else it wold be. i know for sure that it is not a fuel leak. I getting ancy because i have a trip to canada next week and it is going to be cold. relays are going to be here tomrw so i will update you all then. as far as the meter i will see what i can do.

 

[edgeman]

well sorry i havnt updated in a while, i was in canada hunting. i put the new relays in and they grid heater works like a charm. thanks everyone for the help it was very helpfull.

 

[Missouri Mule]

The voltage should read at least 12. 5 volts. Engine running volts should be over 14. Engine not running grid heaters on (pre cylce) volts are 8 I belive. Engine running grid heaters on (post cycle) 10 volts.