Need help - Mysterious electrical issue?
Thread Starter
|
Elder User
Joined: Jul 2004
Posts: 920
Likes: 0
From: Westminster, Colorado
Need help - Mysterious electrical issue?
This is for a 1967 F-250.....was running fine, then one morning, no power whatsoever....
Checked battery and it read 0.32 volts, disconnected it from the truck and it immediately jumped to about 3.5 volts.
After recharging battery, reconnected it to truck, got a spark as i connected the terminal......noticed, with keys OFF, my aftermarket Tach was showing 2000 RPM and gradually dropping as battery drained.
So, swapped coil - same thing
Disconnected points/tach from the coil - **strange part** - when I reconnected the positive terminal this time, the engine began trying to turn over(ignition off / no key in the switch)....
No burn wires visible.....with everything off, I'm reading at least a 0.5 volt load on the battery.....
Seems I heard before a bad Voltage Regulator would try to make the alternator into a motor.....is this what's happening? How to test?
Any clues?
Checked battery and it read 0.32 volts, disconnected it from the truck and it immediately jumped to about 3.5 volts.
After recharging battery, reconnected it to truck, got a spark as i connected the terminal......noticed, with keys OFF, my aftermarket Tach was showing 2000 RPM and gradually dropping as battery drained.
So, swapped coil - same thing
Disconnected points/tach from the coil - **strange part** - when I reconnected the positive terminal this time, the engine began trying to turn over(ignition off / no key in the switch)....
No burn wires visible.....with everything off, I'm reading at least a 0.5 volt load on the battery.....
Seems I heard before a bad Voltage Regulator would try to make the alternator into a motor.....is this what's happening? How to test?
Any clues?
Thread Starter
|
Elder User
Joined: Jul 2004
Posts: 920
Likes: 0
From: Westminster, Colorado
Well, the only other out of the ordinary thing is my speedometer cable seems to have broken.....but I don't think that could have any electrical interactions....cable casing still intact and all....
The reading 2000 RPM on the tach with engine OFF and the strange engine rotating on it's own feel like they could be symptoms....but I can't find anything good on the Voltage Reg or the alternator other than "swap them out and see if it's fixed"
New User
Joined: Apr 2012
Posts: 7
Likes: 0
Battery discharge.
Lets keep this very simple. Disconnect the negetive terminal from the battery. Then recharge the battery to full charge with the ignition switch off. Then connect a test light between the battery ground post and the vehicle ground cable.If it illuminates you have a electrical draw.You may start a prilimanary search for the source by removing fuses from the fuse box to see if the light goes out. If it does,you have a circuit to trace.
FWIW
Fenceclimber
FWIW
Fenceclimber
Senior User
Joined: Aug 2010
Posts: 419
Likes: 0
From: Sandy Level
Trending Topics
Thread Starter
|
Elder User
Joined: Jul 2004
Posts: 920
Likes: 0
From: Westminster, Colorado
Did the prelims already....still drawing and ruled out starter and alternator.....So, starting with fuses in the morning....
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Cargo Master
Joined: Feb 2006
Posts: 3,008
Likes: 250
From: North Pole, Alaska
Starter relay is definitely bad for it to start with connecting the battery. I had that happen with a 77 F-150 and a 74 AMC Gremlin with a Ford starter. Are very cheap to replace. Luckily the F-150 was in reverse in the garage, as it backed out by itself.
Thread Starter
|
Elder User
Joined: Jul 2004
Posts: 920
Likes: 0
From: Westminster, Colorado
So.....oddly enough, nothing seems to be wrong this morning.....battery charged up overnight, no draws of voltage on any systems, started up and was charging at 14.12-14.16 volts......????? (I hate electrical issues!!!! lol)
Ordered new solenoid and Ignition switch to be sure.....
The only thing I completely disconnected was the car stereo, to rule out any power draw for it's memory.....perhaps it was fried somehow?
Ordered new solenoid and Ignition switch to be sure.....
The only thing I completely disconnected was the car stereo, to rule out any power draw for it's memory.....perhaps it was fried somehow?
Posting Guru
Joined: Mar 2006
Posts: 1,182
Likes: 1
i'm agreeing with the votes for starter solenoid and/or switch. that's the only thing that would make it try to start by itself.
your solenoid (or switch) may just be flaky, and this could re-occur at any time.
your solenoid (or switch) may just be flaky, and this could re-occur at any time.
Lead Driver
Joined: Jan 2003
Posts: 9,893
Likes: 12
From: Ohio
Wondering "IF" the ignition switch was screwed up and actually left power to the points(burnt them) thus causing current to coil and tach. All this mayhem caused the battery drain. Then the bad switch then got worse and caused the solenoid to activate making it try to start.
That switch is the only things that activates/controls all the things that went haywire. That is why I would start there.
My .02
That switch is the only things that activates/controls all the things that went haywire. That is why I would start there.
My .02
Cargo Master
Joined: Oct 2011
Posts: 2,241
Likes: 299
From: Kenner,La.
electrical problem
I must agree wit rusty wheel an freightrain with the solenoid, do you have a good ground between the battery,body ,frame and engine ? I have seen some strange things result from bad grounds. Kenny Nunez
Elder User
Joined: Oct 2011
Posts: 795
Likes: 0
I was having electric issues thought it was all fix, couple of the times the starter did not quite. Friend of suggest checking hooking up correct grounds, have not had a problem since. Did not lreally have a good chassis ground hooked up.
Posting Guru
Joined: Jun 1999
Posts: 1,083
Likes: 1
Grounds would be cheap and easy to check. You have two...one is the neg batt cable that grounds on the passenger front engine block...just follow the cable from the batt to the block. The other should run from a bolt on your throttle linkage mount, driver's side rear of intake, to a small bolt/screw on the firewall...pretty short cable, maybe 10 -12 inches max. I recently replaced my intake to firewall ground and truck is running much better...old cable insulation was toasty and broken in places, with wire showing through. Also check your batt ground cable for corrosion inside the insulation. Took me about 35 minutes to pull both cables, clean connections with a wire brush, and reinstall both cables.