Go Back   The Ford Barn > General Discussion > Early V8 (1932-53)

Sponsored Links (Register now to hide all advertisements)

Reply
 
Thread Tools Display Modes
Old 04-13-2017, 02:16 PM   #1
cordbob
Member
 
Join Date: Oct 2014
Posts: 74
Default Need somebody smarter than me

Friend of mine has a 48 Mercury stock engine, drive only a mile or so when it warms up go to restart it starter relay clicks starter is drawing amperage does not rotate engine at all.Checked cables and ground connections.Jumped power directly to starter terminal , installed new starter same result.If the car sits for couple hours fires right up.Load tested battery reads o.k I'm stumped engine runs fine drives great?
cordbob is offline   Reply With Quote
Old 04-13-2017, 03:19 PM   #2
Art Newland
Senior Member
 
Art Newland's Avatar
 
Join Date: Mar 2016
Location: Lynden, WA
Posts: 1,556
Default Re: Need somebody smarter than me

Try tapping on the starter lightly? Maybe brushes are sticking?
Art Newland is offline   Reply With Quote
Sponsored Links (Register now to hide all advertisements)
Old 04-13-2017, 04:03 PM   #3
Bruce Lancaster
Senior Member
 
Join Date: May 2010
Location: Madison, NJ
Posts: 5,230
Default Re: Need somebody smarter than me

Sounds like you did check bypassing the solenoid...but I fought a similar problem for a long time. Then I touched the solenoid, and smelled burning bacon and heard screaming. I realized that I had discovered RESISTANCE!
Bruce Lancaster is offline   Reply With Quote
Old 04-13-2017, 04:07 PM   #4
jimTN
Senior Member
 
Join Date: May 2010
Location: Powell, TN
Posts: 2,202
Default Re: Need somebody smarter than me

May have a dead spot in the armature and looses contact on that spot. Not unusual.
jimTN is offline   Reply With Quote
Old 04-13-2017, 04:34 PM   #5
cordbob
Member
 
Join Date: Oct 2014
Posts: 74
Default Re: Need somebody smarter than me

Replaced the starter with a new one , the flywheel and gear on old one was good . Didn't think it might be some kind of alignment issue since it only does it when it gets hot .Both starters have the same problem, do you ever shim starters in flatheads?Jump starting it didn't help so thought battery wasn't the problem.
cordbob is offline   Reply With Quote
Old 04-13-2017, 04:36 PM   #6
Lanny
Senior Member
 
Lanny's Avatar
 
Join Date: May 2010
Location: Mn
Posts: 1,997
Default Re: Need somebody smarter than me

Sponsored Links (Register now to hide all advertisements)
Just curious, have you got a good ground cable from battery to engine,
and from engine to body & from body to frame ?







.
__________________
My Dear, I love to see your hair blowing in the wind....
Ok ok, stop crying, I'll chase after it & get it back for you.

Last edited by Lanny; 04-15-2017 at 10:12 AM.
Lanny is offline   Reply With Quote
Old 04-13-2017, 04:40 PM   #7
flathead48
Senior Member
 
Join Date: May 2010
Location: Upstate,NY
Posts: 872
Default Re: Need somebody smarter than me

Cordbob, do you have heavy enough cables ? I use 2/0, may seem like over kill but my 48 starts when hot, you could also have a weak coil. Just some thoughts.
flathead48 is offline   Reply With Quote
Old 04-13-2017, 05:02 PM   #8
cordbob
Member
 
Join Date: Oct 2014
Posts: 74
Default Re: Need somebody smarter than me

Battery is grounded to the intake of the motor, all cables are stock .Ignition is not an issue the motor does not rotate at all, fires right up when it does.
cordbob is offline   Reply With Quote
Old 04-13-2017, 05:07 PM   #9
JSeery
Senior Member
 
JSeery's Avatar
 
Join Date: Nov 2012
Location: Wichita KS
Posts: 16,109
Default Re: Need somebody smarter than me

Quote:
Originally Posted by cordbob View Post
Battery is grounded to the intake of the motor, all cables are stock .Ignition is not an issue the motor does not rotate at all, fires right up when it does.
I hear you, but grounds are always the place to start.
JSeery is offline   Reply With Quote
Old 04-13-2017, 05:24 PM   #10
flatheadmurre
Senior Member
 
flatheadmurre's Avatar
 
Join Date: Apr 2015
Location: Sweden
Posts: 3,045
Default Re: Need somebody smarter than me

What you got is lack of current...warm motor with higher compression needs more power to turn over.
So either cables/solenoid have resistance or the battery doesnīt have enough cranking amps.
I would take a volt meter and measure the voltage at starter and battery while cranking first.
If itīs good at battery and low at starter follow the cables backwards until you find the voltage drop.
flatheadmurre is offline   Reply With Quote
Old 04-13-2017, 05:26 PM   #11
cordbob
Member
 
Join Date: Oct 2014
Posts: 74
Default Re: Need somebody smarter than me

Thanks for the info .This car is a 100% stock Dearborn winner , owner wants to keep it original I'll try big ground and power ccables to trouble shoot it .Never seen a battery act up when it gets hot but I'm leaning toward that being the problem. Keep you posted on the outcome.
cordbob is offline   Reply With Quote
Old 04-13-2017, 05:31 PM   #12
cordbob
Member
 
Join Date: Oct 2014
Posts: 74
Default Re: Need somebody smarter than me

Battery voltage was 6.43 , dropped to I think it was 4.5 or so.Thanks Flatheadmurre I will try that.
cordbob is offline   Reply With Quote
Old 04-13-2017, 05:31 PM   #13
Fredb_
Senior Member
 
Fredb_'s Avatar
 
Join Date: May 2013
Location: Coos Bay, OR
Posts: 547
Default Re: Need somebody smarter than me

I've got three grounds on mine and used heavy cable with soldered ends. No problems cranking motor. Good place to start.
Fredb_ is offline   Reply With Quote
Old 04-13-2017, 05:51 PM   #14
JSeery
Senior Member
 
JSeery's Avatar
 
Join Date: Nov 2012
Location: Wichita KS
Posts: 16,109
Default Re: Need somebody smarter than me

Quote:
Originally Posted by cordbob View Post
Thanks for the info .This car is a 100% stock Dearborn winner , owner wants to keep it original.
The original car had the proper sized cables. But even if the existing cables look good that does not mean they are carrying the required current. This is both the "+" & "-" side! Are all the connections clean? Like has already been said, if the starter is not turning over (and it is a good battery and starter) then there is a current problem somewhere. Have you tried bypassing the starter solenoid with a jumper cable when it is in this hot/no start condition?
JSeery is offline   Reply With Quote
Old 04-13-2017, 07:07 PM   #15
fortyfords
Senior Member
 
fortyfords's Avatar
 
Join Date: Mar 2011
Location: faucett, mo
Posts: 370
Default Re: Need somebody smarter than me

Not turning over means that you don't have enough voltage to push enough current through a resistance; its one of those three.
fortyfords is offline   Reply With Quote
Old 04-13-2017, 07:16 PM   #16
40FordStd
Junior Member
 
Join Date: Mar 2013
Posts: 4
Default Re: Need somebody smarter than me

From what I remember when I had my starter rebuilt - the rebuilder said that there is alignment bumps in the starter pieces (male & female). Make sure they are aligned perfectly or it will cock the rear bearing resulting in binding and no starting when hot. When it's cold, there's enough armature clearance and it will start. Just something to check since you have two starters doing the same.
40FordStd is offline   Reply With Quote
Old 04-14-2017, 12:55 AM   #17
Alaska Jim
Senior Member
 
Alaska Jim's Avatar
 
Join Date: May 2010
Location: Palmer, Alaska
Posts: 1,421
Default Re: Need somebody smarter than me

Ck your cables closely, they could be corroded under the insulation where you cannot see it. this will cause high resistance, especially when warm, and cause the problem you describe. good grounds , and more than one, cannot be stressed enough on a 6 volt system, along with the proper gauge wire as others have mentioned.
Alaska Jim is offline   Reply With Quote
Old 04-14-2017, 02:06 AM   #18
Paul Bennett
Senior Member
 
Join Date: Sep 2016
Posts: 628
Default Re: Need somebody smarter than me

If the 6.43v good battery voltage drops to 4.5v under attempted warm start and the original and replacement starter don't turn the engine as well as jump starting not turn the engine, you have a mechanical issue, not an electrical issue.

Can a cylinder be filling with fluid temporarily, increasing the torque needed to crank an incompressible cylinder, and that fluid be released from a hot engine as vapor or ??
In any case, forget the grounding and cables and direct your search to the engine loading the starter(s) down.

You initial thread stated incoherently "drives only a mile or so" perhaps a water leak quickly overheating ?? don't understand but I'm thinking that may be related.
Paul Bennett is offline   Reply With Quote
Old 04-14-2017, 02:55 AM   #19
flatheadmurre
Senior Member
 
flatheadmurre's Avatar
 
Join Date: Apr 2015
Location: Sweden
Posts: 3,045
Default Re: Need somebody smarter than me

Starting from the battery...a battery is designed to deliver a maximum amount of instant amps (cranking amps) this is set by the surface area of the battery plates.
If you are trying to draw more current out of the battery then itīs designed to deliver you will have a voltage drop...this doesnīt mean the battery is bad...itīs just to small for you aplication !!
So if the battery voltage drops to much cranking it may just be to small.
So when we have a correct size battery that will deliver the needed current itīs time to make sure it gets to the starter.
This is when ohms law will work against us.
Power of a starter is voltage x current thats why truck starters has become 24V to limit the needs for current and giant cable areas.
With only 6V available we will need twice the current of a 12v starter to achive the same power.
Now we measure over the starter (between case and cable bolt) while cranking, the ideal would be to have the same voltage as from battery but resistance will keep that from happening.
So we got an unwanted voltage drop on the way from battery to starter...how do we identify the problem ?
Grounding issues...measure from battery +(positive ground) to starter case while cranking.
Solenoid issues...measure between solenoid input and output while cranking.
Feed cables...measure between battery - and solenoid input or solenoid output and starter while cranking.
Take notes of the voltage readings and you will find the place where the voltage drops.
Taking it step by step will identify the problem.
flatheadmurre is offline   Reply With Quote
Old 04-14-2017, 04:12 AM   #20
JWL
Senior Member
 
Join Date: May 2010
Location: Fitzgerald, Georgia
Posts: 2,148
Default Re: Need somebody smarter than me

The first thing I would do when the warm engine failed to crank is to put a socket on the crankshaft pulley and see how easily my 1/2" drive ratchet can rotate things.
JWL is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Sponsored Links (Register now to hide all advertisements)


All times are GMT -5. The time now is 05:10 AM.