help with fuel shut off...

[Todd T]

OK the truck has not been pulling up the solenoid at startup. i did a search and started checking some things out last night. here is what i have found can anyone help me out here?



1. cleaned and greased wire terminals(Blue and Orange) at drivers side battery.



2. back probed the fuseable link on blue wire to make sure it was OK- it checked out fine.



3. swapped the fuel shut off relay in the power distribution box on fender with the trailer relay.



4. cleaned and inspected the connector at the solenoid and also greased with dielectric grease.



5. took apart the shut off relay on the firewall and cleaned the burnt terminals. they had some build up of crud on them.



I have a new relay on its way tomorrow. what i found so far is the relay once i had it apart. i could push the contacts together and the solenoid would fire. it took quite a bit of force to get it to make contact and fire the solenoid. I believe the relay is Bad. maybe the coil is open or shorted. every once and while the truck will try to pull up the solenoid and it just squeals, but wont pull up.



I can jumper to it (solenoid) and it fires fast and hard so i dont believe it is bad. if the relay doesnt fix this, what else down the chain could be keeping voltage off the relays coil and not allowing it to work?

 

[Todd T]

boy, you guys are a hard crowd to please I know this is a dead horse subject for most of you, but i have done all the obvious and really need some expert help. PLEASE



I changed the relay out this morning and still nothing. i will pursue this some more this weekend. without tracing schematics all weekend can anyone answer me if the starter contacts have anything to do the the triggering of the fuel shutoff relay?



where does the coil on this relay get energized from? it looks like from the starter motor relay. a brown wire that also energizes teh pull on and hold on coil in the starter. the starter is working fine. no troubles out of it.



it shows a 12g brown wire coming from connector C127 and it is coming from connector S113. anybody know where i can find those? doesnt an "S" mean it's a splice?

 

[illflem]

Sorry Todd, I was figuring someone else would answer. Starter contacts are the next (and probably last) place to look.

 

[barryg41]

Todd said:



it shows a 12g brown wire coming from connector C127 and it is coming from connector S113. anybody know where i can find those? doesnt an "S" mean it's a splice?



The C127 is on the drivers side fire wall. It is grey color. There is three side by side. One is black and two grey connectors. One grey is c126 and the other is c127. Yes, it does connect to S113. It is located by the PDC.



Qouting Todd again:



can anyone answer me if the starter contacts have anything to do the the triggering of the fuel shutoff relay?



I will post what the good book said about the workings of the FSDR.



When the engine starter motor relay energizes, its contacts close and connect circuit A2 from the fuse 2 in to the Power Distribution Center (PDC) to circuit T40. Circuit T40 supplies battery voltage to the engine starter motor solenoid and to the coil side of the fuel shut down relay. Circuit Z12 provides ground for the coil side of the relay.



Circuit A18 from the PDC supplies battery voltage to the contact side of the fuel shut down relay. When voltage is present on circuit on T40, the relay energizes and its contacts close to connect circuits A18 and A123. Circuit A123 supplies power to one of the two coils in the fuel shut down solenoid.



When circuit A123 energizes, the fuel shut down solenoid raises the injection pump shut down lever to the RUN position.



When the ignition switch is released to the RUN position, it connects circuit A1 from fuse 3 in the PDC to circuit A21. Circuit A21 powers circuit F18 through fuse 9 in the fuse block. Circuit F18 supplies battery voltage to the second coil in the fuel shut down lever. When Circuit F18 energizes, the fuel shut down solenoid holds the injection pump shut down lever in the RUN position.



Circuit Z12 provides ground for the fuel shut down solenoid





Todd I got this from a 96' book, but the colors, connector and splice numbers are the same as you have mentioned in your first two posts.



I hope this helps. I really couldnt tell if you had a book in front of your or just getting info off the internet.

 

[Todd T]

Barry,



THANK YOU, THANK YOU, THANK YOU!!



you to, Ilflem



it started out supplying some voltage to the fuel SO relay. the voltage would be there for about 2-5 seconds and then give up.



now i cant get any voltage at any time. it must be a dirty connection or ground somewhere.



should i still look at the starter?



can anyone confirm if the pull up circuit is energized for a bit, at first with the key in the run position. or just in the start position.



like i said, in the run position it would have voltage present for about 2-5 seconds and then give up. even with the key in start position i now and continue to have no voltage on the relay.



AHHH the great misteries in life!!!

 

[barryg41]

From what I can see Todd, you should have power in both RUN and START position of the starter switch. Maybe its the starter switch that is not letting the power get or hold the power to the FSDR.



Just to make sure you dont have one..... Is there a mystery switch on the bypass jumper (manual trans switch for startup) for illegal starts. This can keep power off in the start position. It's a yellow/red 20ga wire right were the clutch arm should be.



Just trying to keep the ball rolling.....

 

[Todd T]

I checked that out Barry i even greased it when i put the jumoer back in.



here is what i have found so far:



i have swapped out both 40A ign. fuses in the PDC also swapped the starter relay with the trailer AND ASD relays. i can leave the shut off relay connected and open connector 127 on the firewall and back probe it with 12v and fire the shut off solenoid. that proves out the new relay, the A18 and A123 circuits. alone with the connector at the sloenoid and shut off relay. I still dont know if it is before or after, the Splice that is to take place out of the Starter relay to the brown wire that is to go to the starter motor. and still does not prove out the starter relay other than i have replaced it with two others. maybe there is a bad connection on the PDC where the relay sits.



I dont see the brown wire that is supposed to go to the starter either. where is it? shouldnt i be able to see it going down there? i of course can find the red feed but no 12G brown wire in site.



I guess i will pull the starter out tonight and clean and inspect the contacts like Illflem said.



hopefully they are the problem and this will all go away!! the hole reason i bought this truck was because it had not been monkeyed with.

 

[barryg41]

I dont see the brown wire that is supposed to go to the starter either. where is it? shouldnt i be able to see it going down there?





Todd, the br T40 wire comes from the engine starter motor relay (in the PDC) and it goes to S113 (between the PDC and the drivers side sender well) splitting to the FSD Relay and the engine starter motor.



Now this might be a stupid question, but is the FSD relay and FSD solenoid in the same case? Or are they seperate? I know you changed the FSDR, but what about the solenoid?

 

[Todd T]

SUCCESS



it was a bad connector on the bottom of the starter relay, inside the bottom half of the PDC. i got it apart and the wire about fell off in my hand.



now that was GOOD one.



Barry, the solenoid is the round thing that actually pulls up and holds up the shut off valve. it is post relay. and i proved it out several times by beeing able to pull it up by applying power to the white wire on it. that is the first thing you should do when you have this type of a problem. if it will pull up by jumpering power to it. there is no need to spend the $270 Cummins wants for one



what did it for me was the solenoid would hold if i pulled it up manually, I figured it was good and proved that it was by applying power to it.



FYI: the t40 circuit is only energized while cranking, the connector 127 is a black connector in the corner of the firewall near the hood hinge. it's the top one of the three there.



thanks Again Barry and Illflem i owe you a tasty beverage of your choice

 

[barryg41]

HEH HEH HEH!!!



Good job!



Matte of fact. . I am drinking my favorite bev... . Day off, helping a TDR bud fix his truck.

Coors Light ... ... ... ..... ^^^

 

[TStetson]

I am having a simular problem. Every once and a while it will start on it's own then i have to go out and pull the solenoid. I have replaced the relay for the fuel shut off. It also every once and a while(it hase been more often now) but the starter seams to be sticking and keeps running. Do you think it is the same as your's if so did you remove the PDS to get the the starter relay conection? Any help would be greatly apriciated. It gets a little old and repeditave when you have to go out and open the hood to start the truck. I need to go buy a manual you guys are talking in Greek.



Thanks

Tony

 

[Todd T]

Tony your poblem sounds more like the starter contacts. you can replace them or sometimes clean them to get a little longer life out of them. but plan to either replace the contacts or the starter.

 

[Joe G.]

Tony,



The manual is a real gotahavit! The one to get is the one from Dodge. The aftermarket manuals just don't do the job. It's such a money saver that it would be cheap at twice the price.

 

[TStetson]

I think i'll stop and get one after work today. Now if i replace them will that take care of my fuel shut off not working or is that just going to fix the starter?

 

[Todd T]

Originally posted by TStetson

I am having a simular problem. Every once and a while it will start on it's own then i have to go out and pull the solenoid. I Q: have replaced the relay for the fuel shut off.



A: this sounds like the shut off relay, or the starter relay.



Q: It also every once and a while(it hase been more often now) but the starter seams to be sticking and keeps running. "



A: this is almost for sure the starter contacts, dont let this problem get any worse it could cause the shutoff solenoid ($270) to short out and fry up, along with the starter motor($240).



Q: Do you think it is the same as your's if so did you remove the PDS to get the the starter relay conection?



A: the starter relay is in the Power Distribution Center, its under the hood on the drivers side (Black box), next to the battery. the relay is labled, you can trade it with another one, the trailer relay is a good one to try.



you may also want to take note of the starter relay and the fuel pump relay positions in there. if the starter ever sticks wide open on you, you can kill it by pulling these two relays. just remember, if those dont stop it. leave the key in the run position and pull the battery cable. this is what happens that causes the solenoid to get burned up.



Tony

 

[TStetson]

Thanks Todd that will help amensly.

Hope to get if fixxed soon it is 9* out side right now.

Have to wait to crawl under the truck.



Thanks Again

Tony Stetson

 

[RJ2]

If the starter locks up and you go to pull the battery terminals,does the key need to be in run position?

 

[Todd T]

Ive heard that if you leave it in the run position the chance of burning up the solenoid is less. I personally have not experienced it (nor do i want to) but i does make sense. in the run position the solenoid is just supposed to hold up, and may release the pull up while all this is going on. (pulling the relays and stuff)



what frys them, is the pull up getting stuck on and it overheats.



you are pretty well SOL if you let the truck get to this condition anyway.



preventative maintenance is where its at... .

 

[QRTRHRS]

Originally posted by RJ2

If the starter locks up and you go to pull the battery terminals,does the key need to be in run position?

I think I read that once. I had left mine off when mine stuck. By the time I got a wrench from my garage which I was right next to, the selenoid had smoked.

 

[Blakers]

Todd, I think I have the exact same problem you did - at least the symptoms are the same. No problem with the starter yet though fortunately. In the last two days my truck has begun to not start reliably. I blamed it on the grid heaters, but then found the shutoff solenoid was not always lifting on its own. It will stay up if manually lifted though. Tomorrow I will check out the connections in the PDC. Where exactly was the bad connection you had? On the relay itself, or in the PDC box?



Thanks to Todd and all who helped him and the rest of us.



BlakeOo.