• Welcome to ClassicBroncos! - You are currently viewing the forums as a GUEST. To take advantage of all the site features, please take a moment to register. It's fast, simple and absolutely free. So please join our community today!
    If you have problems registering or can't log into your account, please contact Admin.

More electrical gremlins...

Bronconaut

Contributor
Jr. Member
Joined
Apr 23, 2006
Messages
79
Went to crank the Bronco the other day, hit the switch and 1 click then nothing. Tried again - this time it cranked, no problem. Didn't think anything more about it til yesterday. Went to crank - hit the switch, nothing. Except this time - never would do anything. So I thought maybe the posts needed cleaning, did that - fired right up. Today, no crank. So I get out the voltmeter - 12.5 volts at the battery. Turn the key to on (not crank) and what?!?!? - the VM shows 6.8 volts. So I start poking around - if the voltmeter positive is on the battery post - 12.5 volts. If anywhere on the cable down to the solenoid - 6.8 volts. Turn the key off - 12.5 volts. I switched out the solenoid with another one - same thing.

Where do I start?

Key off
IMG00543-20120312-1627.jpg


Key on
IMG00544-20120312-1627.jpg
 

BUCKNBRONK

Sr. Member
Joined
Jun 30, 2011
Messages
521
Loc.
fresno
Bad battery. Do a load test. batterys will show 12+ volts under no load but will crap out as soon as it has a current draw.
 

Viperwolf1

Contributor
electron whisperer
Joined
Aug 23, 2007
Messages
24,448
Start by taking the battery clamps off. Clean them and the terminals until they shine. Coat the contact surfaces with dielectric grease and put them back on. Do the same for the ground cable connection on the block. Make sure solenoid is grounded well too.
 

Rustytruck

Bronco Guru
Joined
Feb 24, 2002
Messages
10,872
next time it acts up turn on your headlights have someone key the starter while you loock at the headlights, if the lights dim all the way out the battery is amiss if the lights stay brite and the starter doesnt work it is in the starter circut.
 

Rustytruck

Bronco Guru
Joined
Feb 24, 2002
Messages
10,872
In looking at your picture you also need to pull your solonoid and clean up under the bracket. The solonoid need this good ground.
 

Bronco717274

Bronco Guru
Joined
Jan 27, 2008
Messages
1,199
Loc.
Tremont, Ms.
What is that small red wire under the small red with blue stripe push on wire on front of the solenoid? Thats not supossed to be there. It's only hot when keys in the start position. Unless someone put it on to give 12 volts to coil when starting. If it doesn't go to coil it's in the wrong place. Put a couple of table spoons of baking soda into a big glass of water and stir until desolved, pour on top of battery and both posts. It will help clean off corrosion on top of battery.
 
OP
OP
Bronconaut

Bronconaut

Contributor
Jr. Member
Joined
Apr 23, 2006
Messages
79
Thanks to all who responded. The positive battery cable connection had a burr on it that kept the cable from getting a solid connection all the way around the post. The dremel with a sanding drum took care of that. I had used the wire brush tool and had everything nice and shiny but that wasn't enough. A spark at the post made me take another look there.

BTW - I have ground wires from the negative battery post to the base of the solenoid, voltage regulator as well as the alternator ground post.

The "red wire" is where I ran a replacement wire from the ignition through the neutral safety switch - the old one was hit or miss. I stuck the old one on to cover the post. It doesn't go anywhere anymore.

Thanks again!
 

nate213

Jr. Member
Joined
Mar 13, 2012
Messages
69
Loc.
West jordan, Utah
does the voltage regulator need to be grounded? i have a cut wire on the top bolt that holds my VR on to the inside wall. it was cut when i first bought my 66.
 
Top