Engine/Transmission (1994 - 1998) How do I wire the fuel shutoff solenoid?

[DPinkston]

The fuel shutoff solenoid has 3 wires running to it. If memory serves, they are red, white, and black or blue. What do each do? If there were just two it would be no brainer, but the third one kinda throws a kink in it.

Thanks,

Danny

 

[BCaldwell]

Hi Danny, If I am not mistaken one wire is ground(black)? one wire is to open the solenoid for starting the third wire keeps it open to run position. The sart position takes 12 volts or there abouts and the run position takes a lower voltage to keep the solenoid open. If you have a volt ohm meter then you can ckeck the leads to see which is which.

Hope this helps.

Bill

 

[Joe G.]

Both "hot" wires are 12 volts. The small colored wire is the run position and goes directly to the run position on the ignition switch. The large white wire is the start wire. It is high current so you need a relay. Get a 70 amp relay. An electronics store should have it or can get it for you. Radio Shack does not have a 12 volt relay with more than 30 amp capacity. Make sure that this circuit is fused and directly from the battery. The trigger for the relay is from the start terminal on the ignition switch. Use #10 wire for the white and the ground.



Some people use a pull cable instead of wiring it.

 

[WBlackburn]

I have heard that if this goes bad the engine shuts down because no fuel is getting to the injector pump. If this happens in aa most inconvient place is there a way to get it started so you can get home. Seems like I seen a post that alows this. /

 

[Joe G.]

The hold circuit is a very rare failure. In fact, the fuel solenoid pull on circuit seldom fails. It can get dirty and stick. When it appears to fail it is most likely a relay or fuseable link problem. A stuck starter contact can burn it up.



If it does fail you can tie it up with a piece of wire or a tie wrap.

 

[DPinkston]

The large white wire is the start wire. It is high current so you need a relay. Get a 70 amp relay.

The white wire is no larger than the other wires. It doesn't look heavy enough to draw that many amps. Why is there a different input needed for run and start? Is start a richer setting? The shut off lever on my diesel tractor has a spot where you are supposed to set it during cranking in cold weather. I guess this serves the same purpose?

Danny

 

[Bloomy]

JoeG

Where is the relay located? On mine when I turn the key it just turns over. I reach my hand in there and engage the selenoid and then it will start. Is this just a relay problem?



thomas

 

[Joe G.]

Danny,



You can use a 30 amp relay, but it won't last as long. The solenoid has two circuits. Pull on and hold. The hold does not require a lot of current so it just connects to the run on the ignition switch. The pull on requires more current than the ignition switch can handle so a relay is necessary.



Thomas,



The relay is the large one on the firewall near the master cylinder. Your problem could be a relay problem. That is most common for this symptom. The other is the blue wire from the positive battery terminal. That is a fusable link and is prone to failing. If both the relay and the blue wire are ok, then the linkage from the solenoid to the pump lever may be dirty and sticking. Also check the rubber boot on the bottom of the solenoid. It can be in bad shape so dirt gets in the works. The boot can be replaced with a piece of bicycle tube and some tie wraps. Just take your time and check things. This problem is not hard to find and fix.

 

[DPinkston]

Now I understand. Thanks for the replies.

Danny

 

[Bloomy]

Thanks Joe



It ended up that when I looked around to start testing things the nut on the positive battery terminal where the blue fusable link is attached was half-way off. Cleaned it up, tightened it and it works now. Thanks



Thomas