Topic: Starter question?

[BLACKDOG]

My starter decided to go out on me this weekend.   I had an extra one that came with the engine I just put in my truck.  I had to go get some other stuff, so I took the starters down to Autozone to be tested.  The starter that was in my truck when hooked up to power turned, but too slowly to start anything.  The one that I had layin around however, fvired up and spun like it should IMO.  But the guy at Autozone said that it was bad as well   He said the max output or input (dunno which) for my trucks starter is 114 amps??  And it was crankin out 140 amps.  He said I would get a few starts out of it, but that was it.  So I put that one in my truck (dont have $120 to spend right now) and so far it has started fine.  Was the guy tryin to make a sale?  or am I doing something that is gonna hurt my truck?  or is this starter really gonna go out after a few starts?  Can someone explain this to me?

Thanks

[reklund5]

BD-

Don't you know better than to buy anything from Autozone?  Dude was just trying to make a sale.  Chances are that all your old starter needs is $20 worth of contacts from Toyota and it'll go another 100k miles...  Leave the new one in there, be sure your connections are clean and tight and don't worry about it.  Put a set of contacts in your old starter and save it for when you need it.

Ryan

[BLACKDOG [OP]]

BD-

Don't you know better than to buy anything from Autozone?  Dude was just trying to make a sale.  Chances are that all your old starter needs is $20 worth of contacts from Toyota and it'll go another 100k miles...  Leave the new one in there, be sure your connections are clean and tight and don't worry about it.  Put a set of contacts in your old starter and save it for when you need it.

Ryan

Thats what I was figuring.  I'm gonna rebuild the old one too.  I wasnt going to pay the 125 with exchange he was askin either, I would have gone to kragen and gotten their autolite for 109.99
I would have just taken my parents car, and rebuilt one of them this week. 

Thanks Ryan

[Prismo]

I seem to remember you can flip the contacts over to get a clean surface. Am I wrong?

[BLACKDOG [OP]]

So what is the deal with the Amperage? or is that complete :bull crap: ?

[reklund5]

He's talking about the amperage DRAW of that particular starter.  If your charging system is in good order and the battery is fine, I wouldn't worry about it.  Basically, if it draws rediculously high amps it's because the winding in the starter motor is all fawked up.  I've personally never seen a Toyota starter fail due to bad windings or excessive amperage draw.  Just about the only thing that ever goes out is the contacts and plunger.  If you install the new contacts nice and straight and polish the contact surface of the plunger, it'll be fine.

 

I seem to remember you can flip the contacts over to get a clean surface. Am I wrong?

No, you can't flip the contacs as they only go in one way and they're "L" shaped.  They only really wear on one side, but can't be flipped.

Ryan

[BLACKDOG [OP]]

Cool, thats kinda what I was figuring, as long as my truck puts out enough, it'll crank the starter right?  Is 140 compared to 114 ridiculously high?  Sorry, I'm trying to understand this electrical thing.

[reklund5]

No, 140A draw isn't that high- and that reading is only as good as the machine that they have over at Autozone.  I'd be willing to bet that it's not calibrated properly anyway and gives a false (tho probably unintentional) reading. 

Amperage is the "current" or electrical flow moving through a wire ( in your case, the windings of the starter motor require 140A to flow electricty through the winding.  Voltage is the force that pushes the current through the wire.  Voltage can also be viewed as pressure "pushing" the electricity down any given wire. 

Does any of this make any sense?

Ryan

[BLACKDOG [OP]]

So amperage measures the flow, and voltage measures the force pushing the flow?  Is that right?

[reklund5]

yeah, exactly.  You can think of it like water in pipes.  A 1/4" copper tube at 25psi doesn't output as much water in say one minute as a 1/2" pipe at 25psi in the same minute.  You can raise the pressure (voltage) of the smaller pipe and still not get much more water out of the pipe, BUT if you raise the size of the pipe (amperage) you get more water.  Thats why a 12V starter at 140A has more power than a 120V motor at say 2A (a typical electric drill motor)

I'm trying to remember back to the basic electrical course I took a while back...so forgive me if I confuse you.  I even had to go dig the book out and look this up...

Ryan

[BLACKDOG [OP]]

Gotcha. The waterthing really helps. Never thought of it that way.  Thanks Ryan

So that is why fuses blow when you overpower stuff in your truck, is because the radio forexample draws too much for the trucks electircal system to work, and the fuse is a safety measure to protect the truck?  I'm tryng to relate this to smething else, so I know I understand

[robinhood4x4]

Specifically, fuses protect the wiring, not the electronics.  So you should design an electrical system so that the fuse amperage is lower than what the wire is rated for.  Otherwise, the wires will burn up, start a fire and you can make smores on the side of the road. 

BTW, 4crawler has those contacts for sale too.

[mr4x42u]

never buy a starter from kragen or schucks,,just a fyi..replacing the brushes will alomost always fix a toy starter,,and will last longer than anything aftermarket,,IMO.

I would not worry about the draw of your starter..I think a normal starter should pull around 100 amp,,140-150 seems normal to me with wear..most bad starters I see pull over 200-250 amps before they go bad..Run what ya got and just replace the brushes,,,should be just fine..maybe use a little 320 grit sand paper and lightly clean the surface the brush rides on..

[brainlessfool]

140 amps is not bad.  Heck I've got a starter at work that pulls over 600amps.  it's truning a cummings. 

[reklund5]

Blackdog-

Exactly.  Fuses are there as a safety measure (as robinhood said) to protect the wiring.  Excessive amperage draw causes excessive heat.  The fuses basically melt apart to protect the wiring in the event of a short or an overloaded circuit.  Ever look at a dim light bulb real close?  The filament in there lights up because so much current is running thru such a small wire, causing it to glow intensely.  A light bulb is basically a vacuum chamber with a filament inside it.  In a vacuum, it won't burn thru until a much hotter temperature, allowing the light bulb to glow.  A fuse, on the other hand, burns quickly and blows apart.

Capiche?

Ryan

[BLACKDOG [OP]]

capiche ( I think )

Thanks Ryan