Help!!! with a re-wiring problem!!!

[electraman]

Here's my problem...I just rewired my 78 CJ7 , AMC 304 , 3 speed. I used a NOS still sealed under dash harness. The reason that I replaced it was because the fuse block was broken in half. I used an NOS so it would be plug and play.
This is what is going on... everything works, but when I start it, nothing, the only that happens id the volt meter goes to zero. I have checked the battery and it test good. I have put a new ignition switch on too ( one over the column). I put a new solenoid on as well...Nothing... I have put a jumper on each side of the solenoid I the motor turns over. I have ran a ground wire to the solenoid as well...
Any suggestions?

 

[cerrajero]

if the motor turns over and runs after you "jumper" the solenoid the usual thing to suspect is the solenoid........
that is the only interruption from starting right?
the chance that you got a bad solenoid is still possible

the solenoid is waiting for at least 12.2 volts to create the magnetic field to get the plunger to make contact with the 2 contacts
if no voltage is coming out of the solenoid then the magnetic field was not created

so checking the voltage of battery is needed as well as the input bolt of the solenoid
make sure the battery does not drop below 9.3 volts once the ignition is turned to start
grounding of the solenoid comes from the mounting bracket itself
another place to check
so if you get 12.5 at the solenoid you should get 12.5 out
but there is also the possible loose bolt or nut simple as it sounds its still a possibility

 

[electraman]

Thanks, I will give it a try and post if everything checks out!

 

[BusaDave9]

everything works, but when I start it, nothing, the only that happens id the volt meter goes to zero.

Ok, so the starter motor won't turn the engine over. If that is right either your starter is not getting 12 volts or it's bad. Don't replace the starter yet. Lets check some voltages. A test light is good enough.


Remove the 2 smaller wires from the starter solenoid but notice where they were connected. Turn the key to ON. The small red wire should have 12 volts. If not you have a wiring problem.

Next ask someone to turn the key to Start. Check the voltage of the small blue wire. You should have voltage there only when the key is turned to start.

You can also test the starting system by jumpering the solenoid.
Turn the key to run. Remove the blue wire from the starter soleinoid and use a wire to jumper 12 volts from the battery to the post on the solenoid. That bypasses the key switch and turns on the starter.

Or with the key to run jumper 12 volts to the big cable to the starter. It's the big black cable in the above pic. Use a jumper cable for this since it will be drawing lots of current.

 

[cerrajero]

X2 agree with busa

Morning dave

 

[electraman]

Ok, I have tried this. First the battery is only showing 11.94 volts at the terminal. I ran a ground wire from the battery to ths solenoid bracket. I did put my meter on eash side of the solenoid terminals and had the key turned to start. no voltage to the starter. I did put a jumper wire to the post on the solenoid and the started didturn the motor over. Starter is fine.

Dave I will try your test later today when I have some help!

Thanks for everyones help!

Shaun

 

[BusaDave9]

Morning dave

Morning Greg

I did put a jumper wire to the post on the solenoid and the started didturn the motor over. Starter is fine.

Where on the solenoid did you jumper 12 volts? If you put your jumper where the big cable goes to the starter then you only tested the starter but that's good.
If you jumper the post where the small blue wire goes and the starter turned then you are also testing the starter solenoid.

EDIT: if you've been doing wiring changes verify that the small wires on the starter solenoid match with the picture above.

 

[electraman]

Ok Dave, here is what I did...Since i have no one here to help right now, I put a jumper wire from the batter postive terminal to the solenoid blue connection. The Jeep started right up and I drove it 5 or 6 miles. Every thing worked great! I take that back, the gas gage I installed dtill doesn't work... sounds more like a solenoid or a broken connection in a wire some where...

 

[electraman]

The wires are in the correct place, I only did the under dash harness since thats where the mess was and the boken fuse panel.

Shaun

 

[BusaDave9]

I put a jumper wire from the batter postive terminal to the solenoid blue connection. The Jeep started right up

Ok, you have tested most of the starting system. You put 12 volts on the starter solenoid and that activated the solenoid. The solenoid then powered the starter motor and the jeep started.
The starter is good.
The solenoid is good.
The key switch is not delivering 12 volts to the solenoid. You said you installed a new ignition switch so it must be good. When in the run position you are supplying voltage to many electrical parts. Even the ignition gets power and runs the engine.
That blue wire should go through the firewall at the big connector and on to the ignition switch in the steering column carrying 12 volts all the way from the ignition switch.
I am thinking the switch isn't turning far enough. Maybe binding somehow.... unless that blue wire is broken or disconnected.

 

[cerrajero]

in that case
get back in the seat turn on the radio,the fan, flip the turn signal (either way right or left )and the wipers, then turn the key all the way to start.....
does everything come on?
then we have ignition connection problems or wiring
do you feel the key springing back at the starting position?
if no spring back.....then the ignition is in the wrong position

 

[cerrajero]

you said you ran a wire from the positive on the Battery to the solenoid?
then it started fine?
double check the connections on the ignition as well


i pulled this pic from a thread from early this year

 

[tarry99]

Ok Dave, here is what I did...Since i have no one here to help right now, I put a jumper wire from the batter postive terminal to the solenoid blue connection. The Jeep started right up and I drove it 5 or 6 miles. Every thing worked great! I take that back, the gas gage I installed dtill doesn't work... sounds more like a solenoid or a broken connection in a wire some where...

There should be only one wire from the Ignition switch to the solenoid to excite the starter and turn it over, if you can jump around the ignition switch and it starts the vehicle.......then the wire coming from the switch is either dead ( with two people you can run that test) or the switch is bad.........normally that wire is un-fused but in other vehicles some have a fusable link.......also later models sometimes have a clutch or neutral switch that has to have the clutch fully depressed or tranny out of gear in order to start..........If your wiring harness covers many years there is a chance that the harness was built that way and a jumper on that circuit needs to be added to fool the harness into thinking there is a switch.

 

[stljeep]

You seem to be one of the kings of the mountain around here so....
Bought and brought home my 86 CJ7 last night. No mirrors so is this the standard bolt pattern for cj mirrors that I can buy anywhere? And can you help me figure out what size steering wheel I have. From center of bolt to center of next bolt is 1 1/2 inches. And in the world of electrical....when my hazards are on, all the interior lights blink.....what the hell?

 

[stljeep]

Sorry, I can't upload photos.....site won't give me the option. Not sure why.

 

[BusaDave9]

You seem to be one of the kings of the mountain around here so....
Bought and brought home my 86 CJ7 last night. No mirrors so is this the standard bolt pattern for cj mirrors that I can buy anywhere? And can you help me figure out what size steering wheel I have. From center of bolt to center of next bolt is 1 1/2 inches. And in the world of electrical....when my hazards are on, all the interior lights blink.....what the hell?

You should start a new thread. Actually start a separate thread for each question. But as for mirrors, you can buy any CJ mirror and it will fit.

Sorry, I can't upload photos.....site won't give me the option. Not sure why.

Check out this link:http://www.jeep-cj.com/forums/f16/how-attach-images-post-1270/

 

[electraman]

Well Duh is all I can say... Thanks for all the help!!! After taking a week long business trip and a week away from the jeep, I found the problem. Note to self, when taking out the old harness and installing a new one, Make sure you swap out all the jumpers. I forgot the jumper on the blue ignition wires under the dash...Jeep is running and starting great!!!

 

[tarry99]

Well Duh is all I can say... Thanks for all the help!!! After taking a week long business trip and a week away from the jeep, I found the problem. Note to self, when taking out the old harness and installing a new one, Make sure you swap out all the jumpers. I forgot the jumper on the blue ignition wires under the dash...Jeep is running and starting great!!!

Jumpers!............see that wasn't that hard was it?