Won't start - think I have a ground problem

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Joined
Jan 14, 2013
Messages
1,547
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Location
Ohio
My Car
1973 Convertible 351c 2V
OK, my starter selenoid buzzes, and teh starter will not crank.

I'm pretty sure I have a ground problem.

1973 351c...

Can anyone tell me where to look for all the usual suspect areas that would cause a ground issue that would cause the above?

And is there a good procedure to check for bad or weak grounds using a multimeter?

 
Set the digital meter to DC volts at a range that will read 12 volts (probably 20 volts). Connect one lead to the battery ground terminal and the other lead to a good (clean) ground on the engine and to the frame of the solenoid. If the ground is good the meter should read zero. Also run this check when trying to crank the engine. If the meter doesn't read zero, the higher the reading the worse the ground is.

 
Bad grounds are the bane of anyone's existence with a classic car, Mustangs included.

On these particular cars, the starter relay/ solenoid is typically a place where poor connections can lead to all sorts of issues, considering how many connections are on just two posts.

Take off all the individual wires and clean thier connectors thoroughly, and clean the posts on the solenoid also.

Remove the solenoid from the inner fender and be sure you have a good clean grounding surface there too, and don't forget to clean the backside of the solenoid mount where it contacts the inner fender. Rust-free mounting bolts are another area to help you a bit.

Also, underneath the car: Remove and clean the starter cable from the starter post and make sure you have a good clean connection there.

While under the car, remove the main ground cable from the engine block and be sure you have a good clean contact area and clean cable and a good tight connection.

This, along with good clean battery cable connections at the battery will help you tremendously.

 
At least yours is 'starter' related. Mine was running at fast idle last weekend (trying to run out the last bit of old gas after I added 5 gallons of Premium) when after about 10 minutes, it stumbled and recovered... then stumbled twice and died. Been unable to start it ever since.

I'm not entirely sure if it's the coil, distributor, or Duraspark module. I did a couple of preliminary tests with the voltmeter, and have voltage to the coil's "+ & -" terminals, but I haven't checked the coil output yet. I'm pretty sure it's missing "spark" because a shot of starter fluid down the throat didn't even get a single 'pop.'

I'll know more this weekend when I track it down for real. Good luck with your starter issue!

 
Ok, I think I ruled out a ground issue... But when I disconnected the positive cable at the selenoid and touched it to the negative terminal on the selenoid, all it did was spark... So I think my starter is toast...

 
You need two key grounds: one from the battery to the engine block, and one from the engine block to the chassis, typically the firewall.

Your starter is grounded through the engine block, so check your grounding cable at both ends. If you see any signs of corrosion, replace it.

 
I just ordered a new hi-torque mini starter. UPS Ground - should be here in a week or so.

Looking forward to swapping it out, and I'm not in any hurry to crawl under the car... Wrenched my back a couple days ago...

 
Hey, i had the same problem. it turned out that the wire from my starter to the solenoid had melted onto my header and was shorting out there. check that.

 
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