A few quick wiring questions!

A few quick questions. I have purchased new battery cables, starter solenoid, starter cable and ground cable for the engine to body. I suck with electrical so please try not to laugh

1) Does the fender under the starter solenoid need to be cleaned down to bare metal for it to ground?

2)For the body to engine ground is it ok to take it from anywhere on the firewall to anywhere on the block?

3) With a battery connected and the wires above mentioned all connected and grounds cleaned should I be able to at least engage the starter and turn over the engine?

Mike

 

1. The mounting bolts for the solenoid will supply an adequate ground.

2. Mine gets a ground from the right side engine mount bolt, where it is attached to the block, across the mount to one of the bolts that mounts the engine rubber mount to the frame. It's a heavy wire that has enough slack in it to allow for engine motion at the mount.

3.You have to have the rest of the solenoid wires connected as well, to pass the 12v to the starter, in order to get it to turn over. You have to have your neg. battery cable going to the block, as you can't use a body ground to carry the required starting current

I hope I'm not misunderstanding your question and stating information that you already realize.

 

Hi Rick,
I have the body to engine ground run to the bolt under the coil bracket. Is that going to work? I also tested to see if i had power coming off the solenoid and I do. I have power up to the connector for the harness on the pass side of the engine and I am about to test for power on the ignition switch. I have all the harness connected and don't even have power to the lights.

Here are couple of pics.

Starter solenoid




Body to engine ground



Neg battery cable



Unknown wires. Any ideas on these?



Mike

 

The red one looks like a power supply to the dash area, see if you can find the other end (inside the harness, maybe?). Is the other wire grey, or green? If grey, could it be for the Ammeter?

 

The wires in question look like they are for the altenator. The red one looks like it would go to the output post on the alt and the other could be for the field or reg terminal on the alt. I can't really tell from what I'm seeing in those pics. I'd hate to misread the pictures and give bum advice.
It looks like your neg bat terminal is connected to the front of the block, which would be OK. Your body ground, which is certainly large, is ok.
If you just want to see if the engine cranks over, short the small terminal on the solenoid to the terminal with the cable coming from the bat +. It would be the small terminal that is next to the bat cable connection on the solenoid. That would be step one anyway. If you had 12v to the key side of the coil, then the engine would run, providing everything else is correct.

 

So the large red wire needed to go to the starter solenoid. Now that I have connected it the solenoid and at least it makes a clicking noise now. Also, I pulled off all the electrical tape to make sure the wires were not broken and so far they were all ok. Also is there only 1 wire to the starter?

Mike

 

At least the clicking tells you that the solenoid is pulling in. Now if you have 12v on one large connector and the other large going to the starter, it should turn the engine over when the solenoid clicks, provided you have your neg to the block.

 

It appears to have 12 volts on both sides, but still not turning over.

Mike

 

Then make sure you have a good neg connection at the bat and the block. Then you must have good metal to metal concact at your starter motor. Usually the starter mounting bolts take care of this. Chech for 12v at the starter motor terminal where the big cable connects to it from the solenoid, when you click in the solenoid. If you have 12v there and a good ground, (neg connection), then the starter should turn over, unless that's bad.
I'm going out now, I'll check back here tomorrow to see how your making out. You might have to take this one circuit at a time.

 

but...this can cause a problem if the inside of the hole is covered with paint or the fender has been powder coated.
personally, I would remove the bolts and clean the inside diameter only of those holes; scrape the paint if you have to
To test if this is causing the problem, run an external ground wire by just touching the solenoid bracket to engine ground and then try to start the engine.

 

I truly appreciate all the help. In the morning I will clean the mounting holes for the solenoid (I did paint the fender) and I will check to see if I have 12 volts on the starter.

Mike

 

All grounds should be clean free of rust and paint. The groundside of the circuit is the most over looked. Ground problem most often affect more then one circuit. In you pic. on the fender mounted starter solenoid I only see the battery cable you should also have a wire that feeds your fuse block and a main charge wire off the alt.
I deal with electrical problems on a daily basis and almost half the time the ground is not in good shape but I do work on class 8 trucks and most of them have 1,000,000 miles or more on them.

 

Are you using a meter or a test light to check for 12v. Try grounding your meter/test light on the starter, this will verify your ground. Your starter solenoid on your fender has to ground to work also, could have firewall grounded but new painted fender/tub might not be grounding were they meet.
One more thing, I am sure you already have checked, is your battery charged up or your sure it is a good battery, could say 12v but has no amps to crank starter. Put your meter on the battery, try cranking engine while reading meter, if it is below 10v your battery is bad.
Your project is coming along pretty fast, Looking good!

 

Thanks for all the assistance guys. I am hoping to have a few hours to spend on the jeep this afternoon so I'll go over everything mentioned here.

Mike

 

Well...it looks like you've picked up quite a bit of help that has good knowledge base about your specific questions. Although you have obvious circuits not hooked up, it seemed to me that you'll probably have to attack them one at a time. Trying to get everything running at the same time, without an understanding of electrical systems, could be overwhelming. Hopefully you have a diagram to go by. It would be worth the time to get somewhat familiar with it.
Good luck with this part of you rebuild, what I see so far looks like you're doing it right!

 

I have a 73 FSM but it appears there may have been some changes between 73 and 74. Hooking up the connectors is going ok but some of the loose wires are a little less straigh forward. And it looks like 1 circuit at a time is the way I am going toi be doing this. I'll keep posting questions and pics as I go. Thanks again for all the help!

Mike

 

I just picked up a 74 FSM from ebay. I am sure it'll help out a lot.

Still working on cleaning the grounds.

Mike

 

It turns over. Cleaned all the grounds and muddled my way through the wiring schematic in the Haynes manual and now it is turning over. Haven't checked for spark but will probably get to that tomorrow.

Thanks for all the help so far!

Mike

 

Just to let you know...I was having a good bit of trouble with my 74 Cj5 electrically, getting the engine to turn over, etc. Turns out that I needed to replace the starter. It was drawing way to many amps, and would wear down a battery pretty quick. And yes, there is just one wire to the starter. Take a look at that if it will turn over, but won't start.
Good luck!

 

Quick update to all those that helped out. It starts and runs. I fired it up last night but only let it run for 15 seconds or so as I had no rad.

Thanks again for the help.

Mike