How to test Starter motor

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Model T Ford Forum: Forum 2013: How to test Starter motor
Top of pagePrevious messageNext messageBottom of page Link to this message  By jim kosten on Monday, June 03, 2013 - 03:15 pm:

The skinny:Started 1919 roadster drove it to work.
started up O.K.
Took a few people around the neighborhood for a drive...no problem .Then did not start back up ..
turn key to battery -coils buzz-push the ignition foot switch and the coils stop buzzing and the starter motor is DEAD quiet.No clicks or revolutions whatsoever Checked lotza other posts on possible problems /solutions ..checked the current while pressing the switch down and the starter @ the terminal is getting 6v..so i think it is a problem with the starter..
Basically the starter is pulled and I want to know the correct method for hooking it up straight to the battery to test it with jumpercables...can someone please walk me through the procedure as I have either got a bad starter or i am performing the test wrong ,,,thanks JK


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mike Stitt-Southern Oregon on Monday, June 03, 2013 - 03:46 pm:

If you want to test the starter one cable to starter body one to the post on the starter. Polarity doesn't matter.
Starters typically do not just fail or go open. What you wrote suggest the starer may or may not be the culprit.
When you pushed down the switch and the coils stopped buzzing suggest the starter is shorted (I doubt that) or when you push the button a high current demand by the starter cause the voltage to fall off. Ether a connection or a ground problem or battery.
What do your headlights do? Years ago a simple test was to turn your headlights on and try to start the car. Even with a shorted starter they would go dim, with an open starter they would just shine.


Top of pagePrevious messageNext messageBottom of page Link to this message  By jim kosten on Monday, June 03, 2013 - 03:54 pm:

I did turn the lights on to see if the battery was dead ..but did not leave them on while trying to start it up to see if the went dim...the lights seemed good but will try that as well once i get the starter back in..one more question maybe pertaining to there being a short somewhere..on the volt meter i get readings of 6.18v on the starter body? is that supposed to happen?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mike Stitt-Southern Oregon on Monday, June 03, 2013 - 04:15 pm:

From B+ to body yes.


Top of pagePrevious messageNext messageBottom of page Link to this message  By jim kosten on Monday, June 03, 2013 - 04:29 pm:

well just did the test and hooked battery + to starter terminal and the (-) to starter body ..got some sparks at the body when i connected it..and thought i heard some sizzle sounds coming from the battery..no action on the starter motor and quickly disconnected the battery....as far as the volt meter readings from the body of the starter motor.I got 6.18v when the (+)cable was hooked up to the starter terminal not the body..is that still normal?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Peter Borland. Bathurst. NSW. Australia. on Monday, June 03, 2013 - 07:44 pm:

Sounds like a dead short in the starter motor if what you heard was correct. Any smoke?

Peter


Top of pagePrevious messageNext messageBottom of page Link to this message  By JohnH on Monday, June 03, 2013 - 07:49 pm:

If you have 6V right on the starter motor terminal, then the starter is not drawing current. Something is open circuit inside; eg. connection to the terminal inside, brushes, etc.
The voltage at the starter motor (when loaded down by engine compression and cold oil) will always be less than the battery voltage because of the high current draw under load; 4.5 to 5V is typical.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mike Stitt-Southern Oregon on Monday, June 03, 2013 - 08:54 pm:

Well if it's shorted you will get a huge spark. It may be open but if that so your coils should not have stopped buzzing. Put it in a vice and tie battery to the vice. Clamp the other end to the stud and it should spark unless John has it right(open). The spark should be temporary till the motor spins.
If nothing happens then it may be open.
John is right re the terminal. If the field leads have become unsoldered or cracked you could see a spark as the current ramps up and the connection goes open.
If the field coils leads are open solder them.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Michael Pawelek Brookshire, Texas on Monday, June 03, 2013 - 09:03 pm:

Jim, Did you try the alternate back up starter when this happened? :-)


Top of pagePrevious messageNext messageBottom of page Link to this message  By jim kosten on Monday, June 03, 2013 - 11:26 pm:

No smoke came from the starter ..but also did not leave the battery hooked up too long because these sizzle sounds seemed to be coming from the battery end of things

MIke stitt sorry for my ignorance but when you say the field coil leads you are refering to the wires that connect to the pair of brushes right? They show some bare wire where the are held in place under the curled lip..Also the terminal post looks like it has been soldered before maybe this is the problem..but it is not loose and while maybe not good in the long run seems to be holding everything in place proper..

I have never been able to get it to start with the handcrank ...I definetly tried alot that afternoon but no success yet...GRRR

I will post some pics of the inside condition and maybe there will be something obvious to one of ya'll that i'm not seeing...thanks for everyone's input..JK


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mike Stitt-Southern Oregon on Tuesday, June 04, 2013 - 12:30 am:

I mean the big leads attached to the stud.
Jim the sound you hear at the battery may be no more than a connection especially using jumper cables.
Here's a thought, put the starter in a vice as I mentioned. with one cable attached to the vice. Lift the two power brushes off the armature. Pull them up and the spring will push the side of the brush and hold it. Now touch the stud, you should see no spark. A good indicator the fields are OK.
If it does spark pull the brushes out of the holder and retry. If the spark goes away check the brush holder for shorts.
As to the big field leads on the studs use a screw driver a pry them up, you do not want to peel them off but a gentle prying and watch for flex and the solder giving. Hope this helps.


Top of pagePrevious messageNext messageBottom of page Link to this message  By jim kosten on Tuesday, June 04, 2013 - 01:01 am:

Yes I will give the brush removal test a go in the morning.....

What people's take on using a 12v battery just to test my 6v starter a couple times just to confirm its not a bad battery,,I hear people say a lot that the battery charged/&or tested good but was in fact bad . Could this cause serious damage to the starter or fry anything.only asking cause I don,t have or know anyone with a 6v battery . Suppose I could get the battery tested at shop huh?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Roger Karlsson, southern Sweden on Tuesday, June 04, 2013 - 04:50 am:

I bet you can try the starter with a 12 v battery many times without any trouble - many change their T's to 12v without altering the starter, but many also get broken bendix springs after some use, so there are drawbacks in the long run.

Measure the voltage from your 6 volt battery when it has a load, like with the headlamps on and a coil buzzing - if it's shot or need charging you'll get a low voltage reading.

You should be able to start the car with the hand crank - if not, something is out of whack - or you haven't learned the proper routine for choke, priming, carb adjustment etc, this particular T needs yet?
They're all a little different after 80 some years..


Top of pagePrevious messageNext messageBottom of page Link to this message  By Anthonie Boer on Tuesday, June 04, 2013 - 01:29 pm:

Jim : The best way to test a starter is with a bench tester . 90 Percent of the starter problem is a bad connection between the field coils and the terminal post. On a bench tester the starter has to lift ad least 11 ft pound.
167R
Toon


Top of pagePrevious messageNext messageBottom of page Link to this message  By Roger Karlsson, southern Sweden on Tuesday, June 04, 2013 - 02:26 pm:

When you decide to pull the starter for disassembly or testing, remember to pull the bendix off first before removing the starter from the engine - you can't get the bendix out forwards, it'll damage the coils. Good luck :-)


Top of pagePrevious messageNext messageBottom of page Link to this message  By jim kosten on Tuesday, June 04, 2013 - 04:19 pm:

Ahh,yes Roger ..Wish I had used the forum before diving in head first ....before i posted for help I did attempt to take the starter off the car ...and wondered why it would not come out...after some(light to medium aggressive) wiggling and jiggling left it alone and then the next day removed the bendix cover to get a glimpse of what was holding the starter in there..thats when I met Mr. Bendix and I'm pretty sure I heard him laughing at me in there until I exposed him and removed his cover...so is it almost certain that I damaged the magneto ring/and if so what do i look for(damage wise) to check this...This thread should have been titled HOW NOT TO TEST YOUR STARTER!


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