Starter Motor Sparking?!

[ascott430]

Hey Guys,
So a couple weeks ago I removed a starter which was sparking from the main post to the body of the starter. The nut was fused onto the starter (I assume from the continuous sparks) and was very corroded. I bought a reconditioned starter and installed it andd...still a spark. I attached both black and red wires to the main post and the blk/yel wire to the smaller post as the per the wiring diagram. Any idea what causes this spark?

[T77911S]

you have something else shorting to ground. sounds like something is drawing a lot of current that may not be fused.
the first thing i would do is remove the pos cable from the back of the alternator and try it again.
you may have some shorted diodes. if that does not fix it, let me know, we will go from there.

[ascott430]

So I disconnected the positive terminal from the alternator and there was still a spark when starting. Does that mean that the wire may be grounded between the battery and the starter?

Alex

[thejlevie]

Sparks at the main power terminal of the starter will be a loose connection or a fault in the lug of the battery cable.

[T77911S]

i dont see a cable like that partially shorted to ground to where it was only causing a slight problem, btu after 20 some years as an electronics tech and even longer working on cars, i have learned ANYTHING can be possible.
long story short (too late) remove the cable to the alt at the starter to check what you asked about. if it still sparks, its something with the starter, if not, trace the wire or ohm it to ground

[ascott430]

Okay awesome. I tried to remove the alternator cable at the starter and still an arc.

Also, Figured it was worth mentioning that it only sparks at the initial turn of the key. After the spark the starter runs normally.

Would the battery lug need to be replaced even if it looks fairly clean and corrosion free?

And what are the chances that this would happen with both starters?

Just to make sure it is wired correctly...I have the 2 main leads from the battery and to the alternator connected to the large post and then the ignition control leading to the smaller post. The starter signal switch is a little hard to see but it is on the lower stud. There is one other small post on top on the cellenoid which is left open which I believe is for the unloader relay not present in my car. (We bought this starter refurbished from the s14 motor) Is this correct? Here is a picture:

DSCN0438 by ascott430, on Flickr


This is the last problem I am trying to tackle before the car becomes operational so I really want to fix this problem.

Thanks!
Alex

[T77911S]

now i am confused. maybe i have misunderstood what your problem is.
with ALL the cables connected, it sparks when you start it? i thought it was just when you connected the cable you had a big spark. reading your original post, again and again, it is sparking from the main post to the body?

you "tried" to remove the alt cable at the starter? with the alt cable removed at the starter, does it spark?

"ignition control" on the smaller post? what is that

is it sparking from the braided wire on the large inner most post? the on next to the body?

did you clean all the corrosion off all connections

[ascott430]

Sorry for the confusion. Here is a recap.

When we bought the car we noticed that the starter motor was sparking from the main stud (where bat and alt connect) to somewhere either on the body of the starter or to the braided wire. It was hard to tell where exactly it was arcing to since it was so quick. The spark only happens ONCE when we first turn the key to start but then stops while to starter continues to turn the engine over.

The terminal was very corroded and the starter seemed like it was on its way out so we bought a refurbished starter from an s14 motor.

We then bolted it on with no luck...still sparking. We then took the alternator lead off of the starter (per your suggestion) but it did not help our situation.

So I suppose this narrows it down to a problem with the battery terminal, battery lead to the apt, a ground, or starter (hopefully not).

Does that make more sense?

P.S. Ignition control is the solenoid control signal from the ignition switch.

Alex

[thejlevie]

Your update just reinforces what I said. Go back and re-read my post.

[ascott430]

Ok. Should I replace both pos and neg lugs if I can't find any loose connections?

[thejlevie]

Replace the one where the sparks are.

[T77911S]

ah, if he had a lot of corrosion the cable may be corroded in the connector. i can see where it looks like it has been hot. i see i seee said the blind man.

i am not a big fan of a connector like that for a battery cable, but that may be all you have to go with.

[ascott430]

Replace the one where the sparks are.

The sparks are at the main post of the starter, not the battery itself. I'm a little confused now. Should I replace the lug at the battery or at the starter? There are both brand new ring terminals at the starter. I thought you meant I have to replace this part.


Thanks Guys

[thejlevie]

The lug on the main cable at the starter looks like a crimp on lug. Those seldom work for that application. There is a crimp type lug that will work used for welding cable, but it requires a hydraulic tool for crimping. A soldered lug is the best choice. I'd suggest that you remove that cable and take to a welding shop and have them install a lug.

[ascott430]

Okay, I will go ahead and reinstall all new soldered lugs.

Also, I was curious if a corroded ground wire could be a possible cause. I read that the ground from the oil pan to the frame rail can often look alright but won't perform properly leading to starter issues.

Any ideas?

[thejlevie]

A bad engine to body ground strap will cause problems, but not sparking at the starter. If the ground strap is bad, the starter may work poorly or not at all, it can also interfer with operation of the alternator.