Yeah, unfortunately, they don't seem to work weekends.......

 

This may sound like a stupid question (and I'm loaded with 'em this weekend) but did this harness come with any schematics, diagrams, or INSTRUCTIONS?

 

Yeah, p#ss poor ones..........

They seem to show the solenoid with four posts - a large S post (at 9 o'clock) that receives power from the + side of the battery and a large I post (at 3 o'clock) that runs to the starter. They don't show the smaller post at the 12 o'clock position.

They do seem to show two other smaller posts - one under the S post where the purple wire I'm talking about runs to and another post sorta under the I post with nothing running to it. Ford solenoids, of course, only have three posts......

Doesn't make any sense to me.....

 

No they don' t they have 4 posts as shown unless you are staying with 6 volt positive ground.

Battery "B;" Starter "S" are the two big ones sticking out at 3 and 9 o'clock. Then at 4:30 and 7:30 are smaller posts marked Ignition "I" and the last marked for Starter Switch "Sw"
(or something similar).

The positive battery cable runs down to the large B post and power distributes off of that. that is also where your power from your alternator will end up eventually. In a Ford vehicle that is where power is distributed as opposed to the positive battery post in a GM.

As you mentioned, the other large post runs a large cable down to the starter.

The small "I" post runs a wire to the "I" post of your ignition switch that also connects to the wire running out to your coil.

The last post has a wire that comes off the "S" Start post of your ingition switch OR from your starter button if you have elected to have one.

Something like this. There are a number of different flow paths for alternators depending on which type you have. This is generic one wire. For now, just look at the solenoid hook-ups. This is with a starter button. If you use the switch for the starter, the wire from the button connects to the back of the ignition switch.



Ps in this case this set up is for an electronic distributor. If you are using regular points, there would be a ballast resistor on the line running to the coil.

Disregard the 6 volt stuff....busses are fuse blocks or whatever you hav eelected to use for power distribution.

 

Just and only for future reference all point type Fords used a four post, with “I” being a full 12v. ign. ballast resistor bypass (boost).

ford solenoid.jpg

 

I appreciate everyone's help here but;

My solenoid has only THREE posts. A big one at 9 o'clock, big one at three o'clock and small one at 12 o'clock.

big means about 3/8 diameter
small means similar to a 10/32 machine screw.

My engine, tranny and the complete original wiring harnes came out of a 1990 Ford F150. I'm using the alternator, solenoid, and other bits and bobs from the donor. When I do a look up on places like O'Reilly or RockAuto I see that 4post solenoid that you'all are talking about.

However, mine looks EXACTLY like Motorcraft part # SW1951C . THREE posts.

I'll try to include a photo of it from my "electrical questions" gallery. (EDIT - couldn't....) It's the last one in that gallery.

I got an answer back from E Z Wire and it's "it connects to the S terminal". That helps not one !@#$%!#$%^ bit! Their " manual/instructions " show the four post ford solenoid. Obviously all he did was look at their instructions and read them back to me (in an email). In spite of my specifying their instructions use a four post and I only have a three post.

ARGHHHHHH!!!!!!!!!!!!!!!!!

 

RMF

I didn't read every bit of the thread and am not certain where you are at. The "I" terminal that is missing on your solenoid may not be needed. It is for the ignition system. It gives your coil extra voltage during crank on older Ford ignitions like mine. (A ballast resistor or resistor wire steps the coil voltage down to the 6-8V range after engine starts and key is returned to run position. A separate wire off the "I' terminal provides the full 12V to the coil + terminal during crank when you want the spark hottest. I'm not so certain your 89 Duraspark uses it. In the event you have to have it, a four terminal solenoid is 10 bucks. There is an "I" terminal circuitry in the alternator/regulator wiring as well. You got the S terminal correct. Thats the standard GM purple wire ignition switch feed wire.

Somebody jump in here if I am leaving out a detail that would help him.

 

It’s all OK. Your three terminal solenoid is the one used with electronic ignition engines and the small terminal is the “S” (starter)term. You don't need the other terminal.

 

but if its only got 3 posts AND it is THE starter solenoid, then the 3rd post MUST BE START.. (power in, power out and connect & release those two on demand, aka 'start')

see, this is why I used the solenoid on the starter.. no confusion with no labels on the parts..

Sam

 

Thank You!

 

Never mind....Donor car parts in wiring. I'm outa here. You guys will NEVER learn.

 

Julie,

I don't want to get into a p#ssing match on this, but other than problems matching a few connections from a GM based harness ( which they all seem to be) to some Ford components, I fail to understand what your issue is.

It seems to me that using the alternator, start, solenoid, etc that came with the drive train makes perfect sense.

What, pray tell, would be the alternative?

 

The Chargers lost. (sorry Julie, couldn’t help myself)

 

Me thinks she misread your post and thought you were using a donor harness. Many "pros" prefer using all new parts when doing wiring, but in the case of a computer controlled engine, it is best to try and use as many of the sensors and components from the vehicle the engine originally resided in. The ECU is programmed to look for specific values from it's sensors and if it doesn't see them may go into limp mode, shut down or worse be damaged, an expensive result. I know a guy who changed the seats in his car and the car wouldn't start afterwards. After many many "colorful" words and hours of chasing what he thought was an ignition or fuel problem since he had a CEL lite, discovered that he had disconnected wiring to a passenger weight sensor in the passenger's seat. When the ECU went thru it's diagnostics check at start up it didn't "see" the switch and shut down. He jumped the switch connection under the seat and it started right up.

 

You're good Robert, that is exactly what you should do when stuffing a "modern" EFI motor in. Even if you had another choice, modern alternators, ignition etc are inarguably better for your situation. You'll have a few issues getting it wired up since electronics is not your strength. After that you will like it.

Make sure you are soldering connections. At the very least, go back later and do it for the important stuff circuits.