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starter trouble, which stud is +?

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Old 05-27-2007, 09:07 PM
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Default starter trouble, which stud is +?

ok, this really sucks. my ls1 wrangler project is almost done. tried cranking the engine over today and nothing happend

im using the jeeps starter cables and i was told it doesnt matter which stud you connect the + or ground to.

i checked the fuse and the relay for the starter and all are fine. i put the ohmeter on the signal wire going to the starter and when cranked it showed .02v

is my signal wire not giving enough power to flip it over? if not, what can i do to fix it- seems like everything is fine until it comes out of the relay. and i put a new relay into it, but it still gives out the same .02v

any help would be awesome
Old 05-27-2007, 09:49 PM
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Well...you shouldnt have had to do anything different with the starting circuit in order to have the motor turn over... The battery positive wire goes to the big stud on the back of the starter solenoid. And the "trigger" wire goes to the smaller stud. The starter grounds to the block. I dont recall there being a choice, just a big stud and alittle stud.

In any case, you need a full 12v at the big stud which will be battery voltage. You will need a full 12v at the trigger stud. Thats what it takes to engage the starter. You most likely have the 12v to the big stud. If you dont have 12v to the trigger while the key is in the start position, you need to find out why. Either the starter relay has a problem, or the starter fuse. However you starter system is set up...

Also, make sure you have the negative battery cable going down to the block. It should bolt on right above the starter. I have my neg cable going to there, then another wire from the neg terminal to the chassis. I also have a ground strap on the other side of the motor to chassis.

Use a VOLTmeter to check to make sure you are getting the correct voltage at both terminals. 12v constant on the big one...and 12v on the little one while the key is in crank position. You shouldnt need an ohmeter for anything, unless you are just checking to make sure the actual wires are good. Your mentioned you were getting .02v at the trigger...something is goofey there. Check your grounds real good and make sure none of the wires are shorting out.

The only other thought I have on this... and Im not positive... but is it possible that the jeep starting circuit goes through some other check before allowing the motor to crank? And now that you have a new motor/pcm in the Jeep, its not letting the crank operation take place? Just a thought to check out....I dont think thats the case but your jeep is newer than mine so I dont know.

J.
Old 05-27-2007, 10:55 PM
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Originally Posted by ghettocruiser
Well...you shouldnt have had to do anything different with the starting circuit in order to have the motor turn over... The battery positive wire goes to the big stud on the back of the starter solenoid. And the "trigger" wire goes to the smaller stud. The starter grounds to the block. I dont recall there being a choice, just a big stud and alittle stud.

In any case, you need a full 12v at the big stud which will be battery voltage. You will need a full 12v at the trigger stud. Thats what it takes to engage the starter. You most likely have the 12v to the big stud. If you dont have 12v to the trigger while the key is in the start position, you need to find out why. Either the starter relay has a problem, or the starter fuse. However you starter system is set up...

Also, make sure you have the negative battery cable going down to the block. It should bolt on right above the starter. I have my neg cable going to there, then another wire from the neg terminal to the chassis. I also have a ground strap on the other side of the motor to chassis.

Use a VOLTmeter to check to make sure you are getting the correct voltage at both terminals. 12v constant on the big one...and 12v on the little one while the key is in crank position. You shouldnt need an ohmeter for anything, unless you are just checking to make sure the actual wires are good. Your mentioned you were getting .02v at the trigger...something is goofey there. Check your grounds real good and make sure none of the wires are shorting out.

The only other thought I have on this... and Im not positive... but is it possible that the jeep starting circuit goes through some other check before allowing the motor to crank? And now that you have a new motor/pcm in the Jeep, its not letting the crank operation take place? Just a thought to check out....I dont think thats the case but your jeep is newer than mine so I dont know.

J.
on my ls1 starter, there are 3 studs. should i just not connect anything to the 3rd stud?

i was using a voltmeter, its also an ohmeter and a few other things. i just called it an ohmeter

the jeep before this was a manual, but the guy that had it before me made it to where you dont have to push the clutch in to start it

the fuse and relay for the starter are good

i thought the there was suppose to be a neg. from the battery connected to the body, not the engine

my jeeps starter had 3 studs on it also, and theres a wire coming from the neg. battery that goes on the 3rd stud

thanks for the help, just let me know about the 3rd stud and if my neg bat. should be connected to the engine now the frame(i have a ground strap connecting the body to the engine also, but its on the other side of the engine)
Old 05-27-2007, 11:20 PM
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My LS1 start has two larger studs and one smaller one.

The large outer stud should be a large cable to the Pos + from the battery, The 2nd inner large one should not be used for anything. The smaller stud should be from the ignition/crank to engage the start.

You should have a large ground from the battery to the block and also a smaller one to the body, I would add a few more grounds that connect the frame to engine and body/fireway. A lot of electrical problems can be traced to bad grounds.
Old 05-28-2007, 12:51 AM
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thats exactly how i have it hooked up

neg. batt. to the block, one from the body to the engine and one from the frame to the engine

it doesnt make any sense, its getting power to the small stud on the starter(when cranked) and power from the batt. on the + stud. then ihave batt. ground connected to the block right above the starter
Old 05-28-2007, 01:41 AM
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your jeeps system might have had a ground type.. try running the crank/trigger wire off a jumper pack or jumper cables.. see if it works that way, then you'll know for sure that its your wiring not the starter..
Old 05-28-2007, 01:45 AM
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Have you tried jumping the start with a remove start to see if it will crank (use the large battery stud to the small term, maybe the starter is bad.

Are you sure that the small term/wire is getting 12v while the key is in the start/crank position ?
Old 05-28-2007, 11:37 AM
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Originally Posted by bczee
Have you tried jumping the start with a remove start to see if it will crank (use the large battery stud to the small term, maybe the starter is bad.

Are you sure that the small term/wire is getting 12v while the key is in the start/crank position ?
well the small stud is getting .2v which is what its suppose to be getting i believe

whenever i put 12v to the small trigger stud, sparks fly but it does turn. i dont think its suppose to receive that much voltage
Old 05-28-2007, 01:02 PM
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.2 volts.. I don't thing that would be enough voltage or carry enough amperage to engage the solenoid. Take the Start out and down to the Kragen/Autozone and have them test it, Could be a bad Start Solenoid.
Old 05-28-2007, 07:50 PM
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Yeah thats starting to sound like you have a short issue with the starter....

Can you send us a picture of how you have things hooked up? That might help. We might be loosing something to translation with the "big stud" "little stud" talk.

Justin



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