Im finishing an engine that has been out of commision for a few years and thought I would test the starter before dropping it in. I wired it direct to the battery with the guidance of THIS thread. Using the following diagram this is how I have it wired:



The positive terminal goes to the S1 location and the S4 location and the negative to the S2 location. Upon trying to connect it to the battery I get one hell of a light show and it seems the starter pops the gear out but does not spin. Mind you maybe it will spin if I hold the jumper to the battery longer but something about the sparks flying tells me im doing something wrong. Please fill me in.

EDIT: Almost forgot 85' 32V US Auto

 

First...........anchor that starter; it develops much torque. I fly RC helicopters which have large starters that are hard to hold on to.

Second, if your not using a switch attach the negative terminal last.

Are the sparks coming from the starter itself?

 

The sparks come from where the final connection is made which is at the battery. I must admit I have been making that last connection at the positive terminal of the battery. Will connecting the negative last make a major difference? I have the starter weighted down so it doesnt spin out of control.

 

Ground goes to the case, not to a terminal. Attach a jumper cable to one of the mounting ears. Positive cable goes to the one big lug that you loosened to remove the + cable. Not too sure about S3 & S4 offhand, but apply +12V to the correct terminal on the solenoid after hooking up the big cables. The two big lugs are shorted directly together when you have power on s3(or is it S4).

 

Applying the negative cable second is standard practice electronics..............almost all modern electrical devices are negative ground.............except for the prince of darkness.

 

I thought that diagram looked familiar!

http://www.928oc.org/tip/hotstart.jpg

What Dave said!

Positive to S1 and negative to the metal starter case - not a contact point.

 

I also have an '85 and I know there is not a ground cable connected to any of the terminals. As Sharkskin says the case is ground. In your diagram S1 is the positive battery cable, the negative batter cable is connected to the housing of the starter, nothing should happen until you connect the S4 terminal to ground. The ground connection of the S4 terminal is like turning the key.

The light show was due to a direct short between the S1 and S2 terminals inside the starter, hopefully nothing fried internally.

 

The current taken by the starter is huge (hundreds of amps!) and will indeed make a huge spark if you use a terminal to make the connection - you'd really need at least a huge switch to do it that way. Ground the case via a bolt hole.

Frankly I woudn't test the starter this way - just too hard on the eyes!

Make the main starter power connection and then just switch the solenoid connection (that normally comes from the starter relay connection - should be labelled '50'). I assume that is connection S4 on your diagram...

The solenoid needs +12v (not gnd) to operate the starter - still high current but nowhere near the starter motor current...

Alan

 

Thanks guys. I grounded thru the bolt hole on the casing now and made the final connection at the S4 terminal like you suggested Alan. Much less spark thank goodness but the gear only popped out and didn’t spin still. I tested the battery and it only has 11.4V so tomorrow Ill pop the hood on the SUV and see what happens with its battery.

Oh and Randy the diagram above was mentioned in the other thread that I referred to above. I just altered it so I don’t have an unnecessarily large picture and can still use the S1, S2, etc designations.

 

If you measured with the solenoid active 11.4v isn't too bad - the starter should certainly run. I think the battery is OK...

So: you need to take the starter in for maintenance - it may be recoverable (perhaps it just needs new brushes?) or just consider a new/good used one?

You might also first try a bit of gentle persuasion with a rubber mallet - move things about a bit - surprisingly sometimes works!

Alan

 

I used the SUV battery and presto! It ran beautifully. The battery in the garage was at 11.4V while unhooked so it needs charging. Thanks again guys. The problem is solved.

 

Sounds to me as if your first attempt had the negative lead going to the switched live that comes from the solenoid into the windings, so should not have damaged the windings, but may have left some nasty scorch marks inside the solenoid housing. Might be worth opening it up and smoothing out any lumps the shorting might have left. Will save the solenoid sticking once you have it back on the car...

 

Good looking out. Will do!