I swear I didn't do a thing to it since I have driven it several times. It did rain pretty heavy but thats all and the engine compartment wasn't wet. I went out last night to crank my truck and it chattered like the solenoid was fizzling out or the battery was low. The cab light and headlights were dim. My solenoid is only a few months old so thinking it might be my battery I checked it and it was fine.

I tapped on the solenoid with my pocket knife and tried again and it fired and cranked and kept on cranking like the solenoid was stuck. I went and got a new solenoid.

Now it won't crank over at all using the ignition key. I jumped the solenoid from the I terminal to the S terminal with the key on and it clicked and cranked right up. I then pulled both the S and I wires off the solenoid and it kept running.

There is a fairly large gauge wire on the large + side of the solenoid where the battery cable is connected. It has a fusible link so I checked on the other side of the link with my dvm and its fine.

Obviously there is something wrong with my S connection but I don't know what. I checked my fuses and they are all good. Is there a fusible link on the S wire back there somewhere? What do I do now?

 

This seems strange, but I'll offer a few thoughts.

If I have it right, ( I just checked a wiring diagram). most Ford solenoids have 3 terminals .
One from the battery (-)
One to the starter (s?)
One from the ignition switch (I?)

It's mpt really a solenoid -- it's a starter relay. Anyway, to activate the relay, you would normally jump the + to the I -- or at least that should work. That would energize the relay, and supply power to the starter. The relay is permanently grounded.

If you actually jumped the S( starter) to the I (ignition), I don't see how that would work because that should only be hot when the key is in start.

That is unless there are moree connections than are shown in the wiring diagram.

Anyway, I suspect that you have a bad ignition switch. You should see 12 v on that point when the key is in start. If you don't the problem goes back towards the switch which goes through either the clutch or the neuteral switch depending on if it's a manual or automatic.

good luck,

ford2go

 

My set up has the battery +, the big cable to the starter, an S terminal and an I terminal. The I terminal goes hot when the key is on. My S terminal is not going hot for some reason. With the key on if I jump I to S the truck cranks but there is some weird back feed because then the S terminal is hot all the time and it continues cranking after I let go of the terminals. My ignition switch is fairly new but it could be that. I think the neutral saftey gadget on the tranny is fried actually. My backup position has never worked since I got the truck going. Thanks for the thoughts.

 

The I terminal supplies power from the Ignition Coil and bypasses the resistance wire from the Ignition switch while the starter solenoid is energized. The power on this wire in the on position is just a back feed from the coil through the resistance wire.

The S terminal gets power from the Ignition switch (ST terminal) in the start position only and then through the safety switch and on to the solenoid. There is not a fuse link in this wire.

 

When it continually cranks, pull the "s" wire off. It should be red/blue depending on the year.

With the "s" wire disconnected, if it is still cranking, then the solenoid is stuck internally. I would go buy another.

If it stops cranking when you pull the "s" wire off, then you are getting power from the "s" all the time, and I would suspect a ignition switch problem or possibly the wires going to the neutral safety switch have gotten against the exhaust, and the power for the reverse lights has melted into the neutral safety switch wires.

 

Are you getting dizzy yet going back and forth from this forum to the 73-79 forum ?

 

I do not know where that "FROM" came from, I know I put a TO there.
It should have read:

The I terminal supplies power TO the Ignition Coil and bypasses the resistance wire from the Ignition switch while the starter solenoid is energized. The power on this wire in the on position is just a back feed from the coil through the resistance wire.

 

I wondered where this post went. I never noticed there was a forum regarding electrical. After I posted it I went back to check and saw that it had disappeared and I had no idea where it went. Occasionally a post will not take or get lost or my computer goes nutso so I posted the question again in the 73-79. Sorry, I didn't know it had been moved. It would be nice to be notified of these maneuvers. Now I don't know how to combine these 2 into 1 if that can be done.

 

Ok y'all. I have isolated my problem down to the duraspark module. There is a 2 connector plug with a white igniton lead and a red/blue. The white powers the box and the red/blue provides a start retard function. This red/blue is crimped to the red/blue start wire in the ignition connector. In the Duraspark this provides a start retard function. In mine its putting out 11.65 volts back to the start lead when the key goes on. The dieelectric is still in the connector so its inside the duraspark module? I'm surprised the thing will even run like this. Has anybody ever come across something like this?

 

Ignition modules are a common cause of start/run with key in certain spots.

Check the other thread in 73-79 forum for other replies

 

I know what my problem is but I have no clue why its doing this. I pulled the connector loose from the duraspark and jumpered the white wire which is the ignition feed. It cranks up and runs fine now. THe red/blue wire from the ignition switch to the duraspark is joined into the Start wire to the solenoid. It should receive juice on start and retard the start up timing. In my case it is putting out voltage any time the key is on. I know its not in the wiring because I have the wiring unplugged at the connector which is like 4 inches from the duraspark box. This has to be ONE of the weirdest problems I've ever had to bug out.

 

I would get another box and try it. You will be fine for now, but when the weather gets hot it's nice to have the start-retard feature to make life easier on the starter.