Solenoid Wiring

Okay, apparently I'm an idiot... I just realized tonight that I don't know how to wire an external solenoid. All the Jeeps I've worked on have had the updated starter with the integrated solenoid. On this '74, it's external, and I've apparently got something wrong. I've ended up with two wires unattached, both terminating at the solenoid. I have a large hot wire from the battery + to one side, and another heavy gauge going to the starter (pretty basic - I get that part!). As for the small terminals, I have one wire going to the coil, and the other going off to never-never land, somewhere to the altenator, I think. These two loose wires both have large ring terminals, so I think one or both go to the larger studs on the solenoid (but one *might go to the battery +, I'm not 100% sure yet - but I have managed to burn up my red jumper wire in the process! R) ). The other (blue) comes from the ammeter. Would it matter which side it goes to?

I'm getting juice to both sides of the coil (as evidenced with the test light) with the key in the "on" position, but the engine won't crank over.

Thoughts? Suggestions? Flamefest? Schematic of solenoid wiring?

 

you might try painless wiring. i downloaded a manual for a jeep wiring kit . it covered all combos of jeep with gm and jeep with ford and before and after certain years. and its free. good luck.

 

It sounds like the wire from the ignition is not on the solenoid. Unless you have the key in the start position you shouldn't have power on both sides of the solenoid. You should have constant power run from the battery and in order for it to send juice across to the side that powers your starter you have to activate it with the s-terminal. On a two post solenoid this is usually the post opposite the battery post. You should be able to figure out if this is true on your solenoid by touching a wire between the top posts and the hot post and seeing which activates the starter. Make sure the base of the solenoid is grounded or you won't get anything. Somebody feel free to correct me if I'm wrong. Hope this helps

 

I agree with Steve's post.



Check out this wiring diagram on the Internet. It will probably help you see how it works. http://www.novaresource.org/starter.htm

Be sure your solenoid is grounded. In other words, just tighten it good to where it attaches to your jeep. If it is freshly painted, or the bolts holding are not real tight, you might not have a good ground. It needs a ground to work.

When the key is turned on the starter switch to start position, it sends 12 volts to the smaller terminal on your starter solenoid. This in turns activates the magnet inside the solenoid to close the (it will make a clicking sound) switch and allow the current to flow directly from the + side o the battery to the starter.

One of the smaller side terminals should have a wire that goes from the starter switch under your dash. It should be marked S. It will have power when you turn the key to the start position. And as soon as you let off of it, it will go off.

 

It depends on the alternator setup you have, but one wire from the hot (starter) side of the solenoid should go to the + side of the coil, (to provide a full 12 volts vs 9 when cranking, bypassing the ballast resistor) and one should go to the alternator to excite it to charge. Hope this helps

 

Tim, there's a '72 manual online at www.c104.net ... the wiring diagram should be similar to the '74.

Very slow download, so just pick the section that you need.

hth

 

So.... the solenoid sitting on top of the tire b/c the fender isn't on yet won't work?

I think I might have found the problem!!!

Thanks guys!!!

 

That might have something to do with it!

 

Ground the solenoid to something and she will come alive!!!!

Just be sure she is out of gear before you try it. Many of us have had close calls with a jeep nearly running over our foot when trying to get the starter to work while standing out side of the jeep. We know :>O

 

That manual is SWEET!!!!!! The wiring diagrams are going to really help out. Thanks a million Tim!

BTW: A jumper wire from the base of the solenoid to the (-) post on the battery fixed the problem.

Thanks for all the help!