Community Forums

hrcincdonald · 05-10-2018, 05:46 PM

can someone please tell me where the relay is for the fuel shut off switch it , It has 3 wires going to it , only have power to the red wire ,I have traced the wires around the Cummins 300 8.3 engine and the white and black and red wires are going to the front of the Motorhome bus , it is a 96 Allegro bus with Freightline chassic , I found 7 relays in the dash but none of them go to the fuel shutoff , it does not have power in the white wire to engage the shutoff valve, thanks for the help Donald

NHRA225 · 05-11-2018, 06:22 PM

Donald- Please tell Us what problem your having 1st of all, and I'm sure others will chime in.

Skip426 · 05-11-2018, 06:30 PM

Does your fuel shut off solenoid , look like the one in this picture?

If so the white wire from the relay is only powered up while the starter is engaged cranking the engine.

hrcincdonald · 05-12-2018, 06:23 PM

yes Skip426 it looks like that one , but the relay is not like that one , I do not think , I contact freightliner and they sent me a diagram of the wiring for the chassic , I been looking for the relay , but do not know if I am looking at the right places and if I am looking for the right thing , I found 2 Ford starter solenoid , like you find on the Ford Trucks , from the wiring diagram that is what controls the solenoid to engage , but when I bought 2 of them to replace them , the motor would not fire up and the engine just kept turning over and had to disconnect the battery cables to stop it , the key switch would not stop the engine so I had to take the battery cables loose ,

any help would be thankful Donald

Skip426 · 05-13-2018, 09:58 AM

Donald , did Freightliner send you wiring diagrams or schematics , or both ?

The diagrams , are marked with measurements from point to point and if you can locate the relay's multiple connector in the diagram the measurements can help narrow down the location , by giving you the length of harness between the connector and a known point in the harness.
If your having trouble with the diagram , send me a PM and we can arrange for you to send me the pdf of the diagram so I can go over it .

EDIT: To send me a PM ( Personal Message ) click on my user name in the top left corner of this post and select , personal message , from the drop box.

hrcincdonald · 05-13-2018, 02:47 PM

they only sent the schematics to me , that is why it so hard to find the relays I have include the 2 files they sent me I hope you can get them , I have a hard time getting around this site

Skip426 · 05-13-2018, 03:58 PM

Files didn't post .
Call Freightliner back and get wiring diagrams sent to you . Much easier to follow and locate parts.

I've sent you a PM .
and this link will take you to the forums learning center , I had so much trouble posting photos when I started here , I printed pages of instructions out , so I could re-read instructions while attempting to post. But then my computer skills are marginal to say the least , when I was in school we weren't allowed to carry those new calculators had to work with a slide rule.
Wan't to scare a kid these days ... hand them a slide rule and tell them they'll need it when the internet, and all computers go down.

http://www.irv2.com/forums/f62/forum...ics-49134.html

NHRA225 · 05-13-2018, 06:26 PM

Once again- Tell us what problem your having !!

hrcincdonald · 05-14-2018, 06:41 PM

the problem is can not fire the engine up , the fuel shutoff is not getting power to engage the shutoff valve, trying to find out where the relays are for the shutoff solenoid ,

it will fire up if someone push the shutoff solenoid up when turning the key to crank I found 2 solenoid like the old Ford trucks have on the fender and changed them , but when I changed them and try to crank it , once it start turning over to crank it hangs up and have to pull battery cables off to get it to stop , the key will not turn it off ,

trying to figure out if they is another relay somewhere else holding it in

I put the old relays back in and the motor was back to normal , but will not pull the fuel solenoid engage so the motor will fire up

NHRA225 · 05-14-2018, 08:10 PM

Here's a schematic of the early to late 90's typical set up.
Mine has a dedicated remote relay/Solenoid on the frame rail near the engine.
Yours may differ.
Yo may want to look at the Starter Solenoid mounted on your Starter.
Fuel solenoid 101- carry wire ties in your tool box, if it fails while traveling just wire tie it open to continue driving.