Starting issue that doesn't make sense..

[sector_ut]

Okay guys I am a long time fan of the site, and have used the board for guidance for a long time. (However, I am just now getting around to becoming a member!)
Here is the issue, and I really need some help on this one.
I have a 69 GMC 1500 SWB that I recently swapped out the engine (rebuilt 68 327 with HEI.) and the electrical (Painless wiring kit.) The solenoid was recently replaced on the starter, the battery has been checked out and is okay at 650 amps, and the alternator works just fine. (tested as well.)

So here is the problem, when I go to turn it over nothing happens, no clicking, nothing... (I do have power, lights, etc.. just nothing from the engine.) However, if I add my charger / jumper to the circuit it starts right up. (grounding on the battery post, not anywhere else on the chasis.)
The engine then runs fine with no problems. As soon as I kill it, the problem returns.
Any ideas on where to start, I am at a loss.

Thanks in advance for any help!

Brian-

[Longhorn Man]

basicly, it'll only start when you give it a jump?

Who tested the battery, and how did they do it?

[tommypic]

if it only starts with a jump . it sounds to me like the battery might have a bad cell . it will have enough power to burn lights but not to crank over a motor . I am with Longhorn Man , Who tested the battery, and how did they do it?

[cdowns]

i'd take both battery cables off clean all 4ends then hook them up and try again

[VetteVet]

WHAT NO OR Well let me be the first.

The statement you made about grounding the jumper on the battery post and not on the chassis is a major clue to me that you have a poor connection on the negative cable. Check that first as well as what CDOWNS said.

It seems to me that even with a weak battery the solenoid should still click. I think you may have a bad solenoid or a poor connection on the S terminal at the solenoid. Either of the above posts may well be your problem though.
If you can, measure the voltage at the S terminal on the solenoid while a
helper turns the key to start. Observe all safety precautions!!!!
If you get 12 volts then try jumping the solenoid S terminal to the large battery terminal on the back of the solenoid. If it starts, this will eliminate all the major players in the circuit , Battery, starter, and cable connections.

[sector_ut]

longhorn and tommypic Autozone tested the battery on their machine.

cdowns I just replaced the starter main cable (2ga) and ground (grounding on the block from the battery 2ga as well.)

vette vet, thanks for the welcome!
I have not checked voltage, or jumping directly on the solenoid will try to do that this weekend....

thanks for the advice guys!

brian

[cdowns]

you need a ground from the engine to the frame also

[sector_ut]

Yah, I have one from the engine to the frame, and from the frame to the cab.

Funny, I found out (before I replaced the primary cable to the starter, that it had been burned through on the headers.) I assume that it was grounding out on it, but find it odd that this would not have blown a fuse. Guess now that I think about it this could have fried the seloniod... (But would that explain the jumper allowing it to start?)

Again, thanks to everyone for their help!

Brian-

[sector_ut]

BTW here is a picture of the truck.
See attached..

[Longhorn Man]

there is no fuse to protect that. The wire woulda melted, or, the battery would have exploded.
I say pull a battery out of another car or something, or go buy a new one. I can't understand how anything other than a dead battery, would do this.

[sector_ut]

No there is no fuse, and yes, it looked like someone had burned then hacked into half of the wire. I think I will try pulling the battery out of my wife's Pilot and give it a try before I try and run a meter down there...

I will let you guys know something soon!

Again thanks for everybody's help!

Brian-

[sector_ut]

Alright, it has been a while since I have got to go in the garage...
Switched out the battery, no dice
Ran a hot wire to the solenoid, started to turn over...
Given all the wiring is new, and there was a major short (negative cable melted off the battery) before ripping all the old frankenstiened wiring out and starting over, my guess is that the ignition switch is at fault...
Anybody willing to confirm as a valid posibility?

[meansting04]

I would think that if it works when you jump it the ignition switch would still be in use and would prove that it works.

[jjk3]

If the ignition switch was bad it still wouldn't start with the charger on there. Take a voltmeter and make sure you have voltage to the starter solenoid while cranking. If you do, then you know the ignition switch is good. Also, put your voltmeter across the battery. While cranking it should not drop below 9.6V or so (I'm a little fuzzy on the exact number).

Take an ohmmeter and test the resistance between the negative battery terminal and the engine block. You should read 0.1 ohms. Generally anything up to 0.5 ohms is acceptable, but the lower the number the better. If you have excessive resistance in the ground circuit, then you just found your problem. My best guess is that you have a grounding issue. Make sure the connections are clean, tight, and free of any paint, etc. Good luck. John

[sector_ut]

Okay, here is a status update and by the way thanks so much for everyones help.

I checked the ground. .01 Ohm across the board. (Cleaned and tightened connections anyway.)

Ran the voltmeter from the wiring block (purple starting wire) and got ~9.3 volts when the key ignition is turned on. Got the same at the selonoid....
Realized that earlier I mentioned that I had replaced the starter.. Not true I had replaced the selonoid. Unless I need more volts at the selonoid to trip the switch, sounds like the selonoid or starter is my problem. (No clicking when I turn the key..)

Can someone confirm?

Thanks in advance!

Brian

[jjk3]

9.3V is too low. Take your ohmmeter and check the resistance between the wire to the solenoid and the ignition switch. I'm guessing you'll have high resistance there, or in the switch itself. That's going to be why your voltage drop is so high.

"Ran a hot wire to the solenoid, started to turn over..."

When you did this, did the engine spin over like it wanted to start? Good luck. John

[Longhorn Man]

did you have that 9.3 when the key was in the on position, or the crank position?

[sector_ut]

Longhorn Man -- the 9.3v was in the crank position.

jjk3-- So should it be around 12v? I had read somewhere that 9.3 was what the old 6v systems ran... So you are saying to check the resistance from the firewall to the solenoid and then around the ignition switch.
And yes, when I jumped the solenoid, it did try to turn over. I went ahead and changed out the ignition switch (I figured it is only $12, might as well eliminate it) , it started to turn over twice, then nothing... dead.

I will check the resistance and get back with you guys.

Brian-

[sector_ut]

Hum.. well I got .00 to .01 ohms on the circuits...
firewall to solenoid.. fuse block through the ignition switch to the neutral saftey switch...
Guessing I have a voltage drop before it is getting to the ignition switch.

Any thoughts on where to start?

[neonlarry]

Start at the +battery post and work your way forward.

[sector_ut]

Okay, so I followed the line from the positive terminal 12.7v to the fuse box, to the ignition switch out of the ignition switch 10.3 to the fuse box engine bay side 9.3-9.7 and down to the solenoid, when I discovered that the I can no longer jump the solenoid. Trying to do so caused a short. Noticed that the bridge connection that goes from the solenoid into the starter motor housing (where the rubber gromment goes around the connection) well the gromment had split and the connection was touching the housing. Pulled the whole unit and tried to bench test the solenoid... nada.
Guess I will be making a trip to autozone.

Would the short at the starter have caused the voltage leak all the way back to the iginition switch?

Brian-

[sector_ut]

Swapped out the starter and it turned right over, unfortunately it didn't stop turrning over when i turned it off. Guess that brings up a new problem...

Thanks for everybody's help!

Brian-

[VetteVet]

Well here is one possibility. When the solenoid is energized it throws out the starter gear engaging the flywheel and at the same time it engages the relay points on the other end to power the starter windings as shown by the red lines in the diagram. If the starter gear is binding in the flexplate gear it will not allow the starter gear to retract and disengage the power to the starter.
This is usually due to the lack of shims between the starter and the block. I would loosen the starter mount bolts and if it disengages then you can properly shim the starter.


-

[sector_ut]

VetteVet-
Nice graphic, yes I believe that you are right. I did not shim it or check for clearance, so my thought is that is most likely the culprit, especially after doing some research on the board and net.

Thanks for the feedback!

Brian-

[Longhorn Man]

loosen the two mounting bolts, let the starter drop down, then bump the key over and see if it spins over.