1991Truck

I have a 1991 F150, 5.0L Short Bed, 4WD XLT that I have had since new and just changed the Starter Solenoid because the starter would stay engaged every now and then and I would have to pull the battery cable to stop the starter engagement.

I should have marked the wires but it seemed to simple! So I pulled off the old starter solenoid from Advance Auto, it had been on about two years and got a warranty replacement. I have the positive battery cable going to the "B" post on the solenoid and that is all that is on that post. On "M" post, I have 3 separate yellow wires, one green that is a Fuse-able Link, and the heavier black wire that goes down to the starter I'm assuming. There is also the small push on wire on the S terminal. I'm thinking one of the wires on the "M" post should be on the "B" post? The battery is good, showing about 12.3V or so but no power seems to be going to anything except the starter solenoid. I have no ignition, no headlight, no dome lights, etc. If someone had a picture of a 1991 F150 solenoid it would help.

HELP. My truck is dead and I'm pretty frustrated at this point.

Thanks in advance.

Chris_1

iTrader: (1)

Perhaps you have them on the wrong posts ? One side should provide power from the battery to the solenoid and to the truck and everything related to it. It will serve to provide power to the solenoid and also be a junction block for providing power to the truck itself.
The other large terminal only gets power when the solenoid is activated by the small wire going to the 's' post. The only thing attached to that 2nd large post is the wire that goes to the starter.

1991Truck

It's possible. The Advance Auto Solenoid has the typical 4 posts, B, M, I, and S. The I isn't used. I only have one cable on the B, the positive cable from the battery, the rest or the wires are on the other post, M.

I still have the original FoMoCo solenoid on a shelf that I took off in 2014 and on it the closest big post to the battery is the B post. The opposite M post was on the opposite side towards the firewall. On the replacement aftermarket solenoid the B and M posts are reversed so it makes you stretch the wires from their original OEM configuration.

Yes, I disconnected the battery last night before I pulled off the solenoid. Just before I pulled the solenoid I had been driving the truck, shut it down, and then started it back up to back into the garage. So it as working then!

I'm kicking myself for not taking a picture but I thought I had it in my mind which wires went where.

1991Truck

Picture of solenoid.

Chris_1

iTrader: (1)

Well the positive cable from the battery will provide power to the solenoid and to the truck so they would all go on the one post. The other post only gets power when you activate the solenoid (by turning the key, which sends power through the wire to the 's' post - except you probably don't have any power going to the truck so the key can't send any power).
When the solenoid is activated (by turning the key) power will go through the solenoid to the other big post and activate the starter. The only wire that should be on that side is the one that goes to the starter.
Clear as mud ?

1991Truck

Picture with post B and M labeled. I thought I just answered this but I guess not.

So Chris the only cable on the M post should be the black one going to the starter? All of the rest of the wires, (Battery positive cable, 3 yellow wires, and the green fuse-link go on the B terminal?

Chris_1

iTrader: (1)

This is on a 95. Slightly different wires but the same idea. The wire on the left on this one is the wire that goes down to the starter. It's the only wire on that post.
The wire on the far right is the one that comes from the + post on the battery. All the other wires are on that post. Yours should be the same idea.

1991Truck

Thanks Chris. I'll jump back on this tomorrow AM. Thanks for your help. I hope that is all there is to correct it. Have a good night!

1991Truck

SUCCESS!! Chris your expert advice worked and saved my bacon. I really screwed up when I took this apart and/or must have been half asleep!

I was so focused on what was happening and so sure I had put the wires back on the right terminals that I didn't step back and think a little harder. I definitely should have taken a picture first, it would have saved a lot of heartache.

So Chris thanks again and I am going to post a picture here, at least for my truck because there seems to be lots of questions about pictures.

This is for a 1991 Ford F150, A/T, 5.0L, 4WD, Extended cab. Two pictures show the wiring hopefully.

Chris_1

iTrader: (1)

Glad you got it sorted out. My wife was trying to figure out what the he** I was doing taking pictures under my hood at 9:00 at night. Some girls don't understand.