Starter relay wire question?
Thread Starter
|
Posting Guru
Joined: Jun 2002
Posts: 1,203
Likes: 2
From: where the deer and antelo
Starter relay wire question?
On the starter relay there are the two large battery and starter wires, and two smaller wires. One is red with a blue tracer that hooks to the "S" terminal, and energizes the relay when the key is in the start position. The other small wire is brown, and has 12 volts on it when the key is in the run or start position. What is the purpose of the brown wire? I can't see where it does anything, and can't find it any where on my wiring diagrams.
I want to use the brown wire to energize my fuel kill solenoid on my Cummins engine. It works in testing, but if it serves a purpose, I will leave it alone.
I want to use the brown wire to energize my fuel kill solenoid on my Cummins engine. It works in testing, but if it serves a purpose, I will leave it alone.
New User
Joined: Jan 2008
Posts: 0
Likes: 24
It allows for 12 Volts to run to the coil during start up only.
Once the engine is running, the power for the coil runs thru the ignition switch and the resistance wire to make the current at 6-8 volts.
Here is an illustration showing how it works
Once the engine is running, the power for the coil runs thru the ignition switch and the resistance wire to make the current at 6-8 volts.
Here is an illustration showing how it works
Thread Starter
|
Posting Guru
Joined: Jun 2002
Posts: 1,203
Likes: 2
From: where the deer and antelo
The fuel solenoid I am refering to is the one that shuts the diesel off when the key is turned off. I don't believe there is anything in the system that will kill the fuel in a collision on my '89 Cummins.
I had looked at your picture before I posted and it don't show the brown wire giong to the starter relay at all. It is the wire that plugs to the "I" stud on the relay. Using an ohm meter it don't seem to connect to anything inside the relay. My main concern is will I do any dammage to the truck wiring if it has the load of the solenoid when ever the truck is running? I havn't put an amp meter on it but there can't be much of a load.
Edit... If it is to bypass the ballast resister and is connected else where in the harness to the coil, I don't think I will ever use a coil on this truck again!
I had looked at your picture before I posted and it don't show the brown wire giong to the starter relay at all. It is the wire that plugs to the "I" stud on the relay. Using an ohm meter it don't seem to connect to anything inside the relay. My main concern is will I do any dammage to the truck wiring if it has the load of the solenoid when ever the truck is running? I havn't put an amp meter on it but there can't be much of a load.
Edit... If it is to bypass the ballast resister and is connected else where in the harness to the coil, I don't think I will ever use a coil on this truck again!
Last edited by jimlj; Jun 14, 2007 at 08:41 PM.
Thread Starter
|
Posting Guru
Joined: Jun 2002
Posts: 1,203
Likes: 2
From: where the deer and antelo
Thanks Dennis! I still am not quite clear in my pointed little head whats going on. If I'm looking at your drawing correctly I would have about 8 volts on the brown wire when the truck is running. I have a full 12 volts. Also is there any reason it connects to the starter relay?
Thread Starter
|
Posting Guru
Joined: Jun 2002
Posts: 1,203
Likes: 2
From: where the deer and antelo
Oops! I figured it out. When the relay is energized, the "I" terminal has full battery voltage. The brown wire is running at a reduced voltage when the truck is running. I am getting about 10 volts which will keep the solenoid open. Where is the ballast resister located on the truck? I would like to bypass it so I have a full 12 volts.
Trending Topics
New User
Joined: Jan 2008
Posts: 0
Likes: 24
That is the The pink fusible link wire (Marked Ballast Resistor) coming from the ignition switch .as shown in the first illustration
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Top 10 Fords at 2026 Carlisle Ford Nationals
Joe Kucinski
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
