Jeep CJ7 won't start/crank, CO just abuses vehicles

The dilemma was that first my CJ& would not get power at all when the key was in the ACC position, I had the steering column rebuilt and reinstalled everything. The voltmeter reads 12 volts from the battery which I had tested and recharged today.

When I turn the key to start the jeep I do not hear anything except crickets.

I am new to troubleshooting jeeps and picked up a voltmeter today. All the fuses looked god when I checked them.

Also my jeep is fuel injected if that makes a difference and I can hear the fuel pump turn on when I push in the clutch.

Any help and suggestions would be much appreciated.

Thanks, Rob

Reply to
rcawrse
Loading thread data ...

Have you bridged the starter solenoid with a big screwdriver to see if the starter motor spools up? If it does, you've likely got a bad battery cable or bad ground. This will also tell if you the battery has enough amps to turn the starter. Another possibility is the ignition switch. On my Cherokee, this is on the steering column. I know this because I have to replace it every 12 months or so, as it seems to melt about that often.

S.

Reply to
fraserwag

Your steering column has nothing to do with the ignition switch, it's not inside there. The switch sits on top of the column way down at the bottom and a rod goes from the switch to the key. Now the connecting rod might have been sloppy, but...

The switches do get out of adjustment from wear on the linkage rods so it has a sliding adjustment on the switch.

I would start down there.

I really don't understand how the fuel pump can come on when you push the clutch. CJ's don't have any clutch switches in them that I know of.

On a normal CJ, I would say check the connections on the starter solenoid on the fender for a bad connection.

One of the best 'inexpensive' books for your CJ7 is the Haynes manual. It is spot on for wiring diagrams.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail > The dilemma was that first my CJ& would not get power at all when the
Reply to
Mike Romain

Measured where and how? You can get a reading of 12V from a cable that only has one wire the size of a human hair connected, but you can't push any reasonable sort of load through that.

My guess is that when you removed the column you bunged up a safety switch on the clutch. I'd check that out before taking anything else apart.

This is based on the 1976-82 I6 models, but its an off-the-shelf Ford system should be close enough for your purposes. I don't know about the V8 and I4 model starters.

The heavy cable from the [+] side of the battery goes to the starter relay. A smaller gage wire should run from the same post on the relay to feed the ignition key switch and all accessories. There should always be [+] present at the back of the ignition key switch, even while off.

Looking at the relay with the battery cable to your left (and the heavy cable to the starter to your right) there are two smaller terminals on the relay side facing you. The one to the left is the "I" terminal, it feeds full battery power to the [+] terminal on the coil during cranking. The small terminal to your right is the "S" terminal, it is fed power from the key switch when you turn it to the "Start" position. If you have doubts, trace the wire from the "I" terminal back to the resistor and/or coil.

With the Jeep in neutral and the wheels chocked (and without your hair and tie dangling in the belts and fan), remove both of those smaller wires, noting which goes where. Run a jumper from the [+] terminal of the battery to the "S" terminal. The relay should pull in -- loudly -- and the starter should engage. If the relay doesn't pull in there's either a bad cable connection or the relay is junk. If the relay does pull in then your problem is someplace between the connection at the battery side of the relay, the ignition switch and whatever safety switch you may have.

That doesn't make sense to me. You'd think that the fuel pump would be dependent on the keyswitch, not the safety switch. If your fuel pump _only_ runs when you have the switch on and the clutch pedal depressed, I'd seriously look for a bunged up safety switch.

Reply to
Lee Ayrton

I will check my Haynes manual and start with the safety switch assuming I can find it, I have tried both the old and a new ignition switch with no luck, I will look at the ignition switch again as well but it seemed to be installed correctly. I cleaned all the connections on the solenoid already and used the AC range set at 750 to check voltage? is that right, anyway the battery read 26 as did the positive side of the solenoid and the black I assume negative cable from the solenoid to the starter.

Reply to
rcawrse

How does the sliding adjustment on the ignition switch work just in case I can't figure it out?

Thanks, Rob

Reply to
rcawrse

What does a safety switch look like and where could it possibly be on an 85 CJ7 Laredo?

Thanks, Rob

Reply to
rcawrse

You need your meter set to 20 V DC. The 'power' or positive wire to the starter from the solenoid only sees 12 volts when the key is switch to 'start'.

There is no safety switch in a 'stock' CJ7 with a standard tranny. An automatic has a neutral safety switch so it only starts in neutral or park.

There are no switches on the clutch or brake that affect starting in a 'stock' CJ7.

A CJ7 does 'not' have an electric fuel pump stock, it is mechanical.

They did not put Fuel Injection into a 'Stock' CJ7.

Just what engine is in that thing anyway?

When you turn the key on, do any lights on the dash light up?

Mike

Reply to
Mike Romain

The key cylinder is tied to the ignition switch via a thin metal rod that travels down the shaft of the steering column. On my Cherokee, this rod takes a 90 degree turn at the lower end, which then goes into the switch. This rod pushes or pulls the sliding portion of the ignition switch. There are a number of different positions the sliding portion of the ignition switch can engage. These positions control the flow of current through the various different spade connectors that make up the switch. The metal "arm" that ties the key to the switch moves the selector back and forth, and thus determines where the current is flowing, START, RUN, OFF, Accessory, etc.

It is possible for the new switch's sliding selector to not be in the correct position when you install it. Thus, when you turn the key, the right connections are not made. I've had to monkey with this a couple of times when I've replaced my switch, manually moving the selector before installing it to ensure it works properly. I've usually determined where the Accessory position is, and the moved the slider to the OFF position before installing the switch onto the column.

On the cherokee, there is another metal rod that also runs along the steering column, used to actuate the headlight dimmer. I tape this one in place before removing the old ignition switch, as if you don't, on the cherokee it can fall right out when the ignition switch is removed, and is a real pain to reinstall.

Reply to
fraserwag

How does the sliding adjustment on the ignition switch work just in case I can't figure it out?

Thanks, Rob

Reply to
SupermanHughesFighter of POSs 24Wimp & SWimp

I figured out the voltmeter and was getting 12 volts from the battery, solenoid connection, and starter connection when the key is in the start position. It is a manual transmission and is fuel injected with a 6 cylinder, I beleive it is a 4.2L. Yes when I turn the key to the on position the dsah lights up and the headlights work well. Thanks for the heads up on th neutral safety switch one less thing to worry about/check. There was a plug type of connection mounted to the engine block a few inches above the starter. I took this apart and it was pretty corroded. I cleaned it as best I could, any ideas what it is and should I just replace it. What are my next steps? Probably working on the ignition switch further and the replacing the solenoid and starter? Anything else to check with the voltmeter and if so please explain how. Your guys help is greatly appreciated.

Rob

Reply to
rcawrse

I was guessing about CJs later than 1980. His statement about hearing the fuel pump when he presses the clutch was what lead me down that path.

Reply to
Lee Ayrton

I am almost wondering if he has a CJ7 or maybe something else? Even the first of the YJ Wranglers had a carb 258 engine up 'til 91.

If he has a custom job like it is sounding, then 'ouch' I wish him luck.

Mike

Reply to
Mike Romain

Lots of useful images here:

formatting link
This one shows the starter solenoid installed:
formatting link
And one taken apart to show how it works:
formatting link
When you turn the key to START you should see +12V at all the terminals, and since this is essentially a big relay, you should hear a solid thunk when it pulls in. But earlier you said that you heard nothing when you turn the key to START. I'd give a hairy eyeball to the solenoid. Just because it shows 12V doesn't mean it can carry the current.

Starter diagram:

formatting link

Is this your motor, seen from the passenger side?

formatting link
If the connector you cleaned was just above and behind the oil filter cannister then it was the sender for your oil pressure gauge.

Check the negative battery cable at the block, clean all faces and retighten.

Reply to
Lee Ayrton

here:

formatting link

installed:

formatting link

works:

formatting link

diagram:

formatting link

side?

formatting link

First, be sure you're battery is delivering enough amps to turn the starter motor. Get it checked at a parts shop if you have any doubt. Once you've done that, performs Lee's step above and clean the negative battery cable at the block. If the cable looks fishy/ corroded, replace it.

With the key in the ON position, put the jeep in Neutral, hand brake on, block the wheels. Put a jumper across the terminals on the Solenoid (or bridge with a big screwdriver), and see if it tries to crank. If it does, its probably the ignition switch that's giving you your problems. If it doesn't, then it likely Starter or Solenoid (assuming you've performed Lee's recommendation above and eliminated the possibility of a bad ground/ground battery cable).

Good luck.

S.

Reply to
fraserwag

here:

formatting link
>

installed:

formatting link
>

works:

formatting link
>

diagram:

formatting link
>

side?

formatting link
>

There's an even quicker (but less precise) field test for the battery: The headlights.

Turn the headlights on. Turn the key to START. If the headlights go out either the battery is bad or there's a corroded connection at one end of a battery cable, one that can carry enough current for the lights but not the 100-odd amps needed to crank the engine. Check the cables (both ends) and try again.

I'd leave the key OFF, since I'm only testing the starter, I'm unsure of what I'm doing and I don't want the engine to grab my tie. I wouldn't try bridging a Ford solenoid with a screw driver, the high-current terminals are on opposite sides and the frame for the part is grounded. Spitzensparken. If it were me I'd clamp a jump-start cable to the + Battery terminal and make contact with the starter side of the solenoid. If the starter engages and runs it is good, if not it is time to pull it out.

Reply to
Lee Ayrton

com/tech/jeep/Motor4.jpg

So here's an update on the issue, I bridged the solenoid with the key in the power/on position with a screwdriver and it engaged the starter. I replaced the solenoid and the starter(as the old starter was smoking and not disengaging the flywheel. Now I have two issues. The first is that the newvstarter , still is not disengaging from the flywheel but is it maybe b/c of the ignition switch, I set the ignition switch as instructed by the Haynes manual and when I turn the key to power position(you know to power the dash etc..) on my jeep it starts the jeep. I am thinking I need to take the ignition switch down one notch. Would proper ignition switch engagement disengage the starter or is there a worse problem here?

What happens if you cross your two solenoid terminal wires???

Lastly, and your not gonna beleive this one but when I was screwing the ignition switch back on the screw snapped off, lucky me anyone know a quick fix or good way to fix this?

Again thanks for all the helpful feedback,

Rob

Reply to
Rob

Ouch.

Your ignition switch when set wrong can easily burn up your starter by leaving it in the 'start' position or cause any other positions not to be right..

At least it isn't 'too' hard to drop your steering column out to get at that broken screw. A serious pain in the butt though. I don't know of any other way to fix that besides drilling it out and maybe tapping the hole for a larger bolt if you kill the threads.

Have you ever figured out what engine is in that thing?

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 'New' frame in the works for '08. Some Canadian Bush Trip and Build Photos:
formatting link
Reply to
Mike Romain

Well that's not good.

Before you do anything else, go to an auto parts store and get a battery disconnect switch. It doesn't have to be fancy, just one of the kind you attach to the battery post that has either a thumb screw that you tighten or a knife switch that you close. Do this so you can disconnect the battery quickly, before you burn up another starter, set fire to your jeep or hurt yourself. Batteries /do/ explode if loaded too heavily.

Which terminals? The solenoid has four terminals, two large high current and two smaller low current. One low-current terminal takes a signal from the START position on the ignition switch to pull in the solenoid. The other low-current terminal feeds straight battery power to the coil during starting.

If there's enough of the screw proud of the hole you might be able to cut a slot in it with the edge of a file or a fine blade and back it out with a screw driver.

Reply to
Lee Ayrton

UPDATE - Well guys, I think I figured out the setting on the ignition switch so that the starter will disengage, but just to be sure I am gonna get a second set of ears. I am going to attempt to drill out both holes for the ignition switch and remount it without pulling the steering column, mainly b/c reconnecting the lower steering shaft was a pain in the ass last time.

I still think the engie is a straight 6cyl 258 4.2L.

Rob

Reply to
Rob

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.