Dead / Dying Starter?
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Junior User
Joined: Dec 2004
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From: Denver, Colorado
Dead / Dying Starter?
1968 F250 4x4, 390, 4-spd
Just put the front end of the truck back together and ready to start up. Problem is, the starter was cranking VERY slowly and irregularly, AND the pos cable at the relay, the relay istself and the cable from relay to starter are getting warm after just a few seconds of cranking.
I tested the battery (12.4 volts), across the starter relay (12.4 volts), and from the pos terminal on the battery to the engine block (12.5 volts).
I replaced the starter (pain in my A$$ since I have headers installed) and it is still doing the same!
I assume the NEW starter is bad out of the box (remanufactured, actually).
I am missing anything?
Thanks in advance.
-Craig
Just put the front end of the truck back together and ready to start up. Problem is, the starter was cranking VERY slowly and irregularly, AND the pos cable at the relay, the relay istself and the cable from relay to starter are getting warm after just a few seconds of cranking.
I tested the battery (12.4 volts), across the starter relay (12.4 volts), and from the pos terminal on the battery to the engine block (12.5 volts).
I replaced the starter (pain in my A$$ since I have headers installed) and it is still doing the same!
I assume the NEW starter is bad out of the box (remanufactured, actually).
I am missing anything?
Thanks in advance.
-Craig
Fleet Mechanic
Joined: Aug 2007
Posts: 1,836
Likes: 261
From: Piney Woods of East Texas
You need to make sure you have a good engine ground to the Neg battery post. Remove any paint that may be on the block. Remove and clean both battery connections even if they look good. You can not see the thin film of oxide that forms.
For checking the soleniod, you need to measure the voltage across it while cranking. If over 0.4 volts you have a bad soleniod. A good one will have Zero Voltage drop. There are to types of material used in the contacts, AL or Cu. Spend the extra $4 for the Copper.
For checking the soleniod, you need to measure the voltage across it while cranking. If over 0.4 volts you have a bad soleniod. A good one will have Zero Voltage drop. There are to types of material used in the contacts, AL or Cu. Spend the extra $4 for the Copper.
New User
Joined: Jan 2008
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Try having the battery load tested before anything else
Batteries are finicky things and unless they are tested on a machine to find for sure if they car capable of powering a starter may APPEAR fine but bad on the inside where it count.
Also Battery cables can corrode in the wire under the insulation. People can stare and inspect it all day long and never see it until they peel a little bit of insulation back and see the corrosion. The cause of many problems starting.
Batteries are finicky things and unless they are tested on a machine to find for sure if they car capable of powering a starter may APPEAR fine but bad on the inside where it count.
Also Battery cables can corrode in the wire under the insulation. People can stare and inspect it all day long and never see it until they peel a little bit of insulation back and see the corrosion. The cause of many problems starting.
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Junior User
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From: Denver, Colorado
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Fleet Mechanic
Joined: Aug 2007
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From: Piney Woods of East Texas
Have you measured the voltage drop across the solenoid??????
This is not the same as battery voltage.
This is not the same as battery voltage.
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Junior User
Joined: Dec 2004
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From: Denver, Colorado
A quick look at the online parts store...
I have always called it the "Starter Relay", but they (and I think all of you) are calling it the "Solenoid" or "Solenoid Relay Switch"...
Either way, it tests at 12.5 volts dry, and 12.35-ish under cranking load.
I have always called it the "Starter Relay", but they (and I think all of you) are calling it the "Solenoid" or "Solenoid Relay Switch"...
Either way, it tests at 12.5 volts dry, and 12.35-ish under cranking load.
New User
Joined: Jan 2008
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How long has this truck been sitting without being started ?
If for a long time,
Starter Drive and Bendix made be all corroded.
Easiest is to remove the starter and bench test it...... & lubing it to loosen everything up again without a load on it.
If for a long time,
Starter Drive and Bendix made be all corroded.
Easiest is to remove the starter and bench test it...... & lubing it to loosen everything up again without a load on it.
Fleet Mechanic
Joined: Aug 2007
Posts: 1,836
Likes: 261
From: Piney Woods of East Texas
You should have 0 Volts across the relay if good. Other wise it is not transfering the current. Sounds like a bad Solenoid.
Most ford's solenoid are on the rt side finder well support, not on the starter. The Bendix is on the starter motor, no Volts required. 1 wire running to the starter.
Did someone do a bowtie swap??? Or did someone do a gearbox drive (high torque) starter on it.
If the solenoid on the starter, you need to measure from battery to motor, top to bottom on most.
Most ford's solenoid are on the rt side finder well support, not on the starter. The Bendix is on the starter motor, no Volts required. 1 wire running to the starter.
Did someone do a bowtie swap??? Or did someone do a gearbox drive (high torque) starter on it.
If the solenoid on the starter, you need to measure from battery to motor, top to bottom on most.
Last edited by blue68f100; Sep 7, 2007 at 04:15 PM.