Voltage Spikes
Thread Starter
|
Elder User
Joined: Jul 2003
Posts: 997
Likes: 0
From: Weston, Nebraska
Voltage Spikes
I have a voltmeter and ammeter in my truck and lately here my truck will start running really crappy, and u look at the ammeter and it's jumpin, and the voltmeter is buried at 18volts, and if i turn on even just the park lights or any other lights on my truck, that little load puts it back down to 14volts and sometimes u turn em off and the volts will stay down, other times no, most of the time it's when i first start it up, the batterys fine, but the extreme voltage is fryin my igntion system. Is my voltage reg. going to hell? I can't really think of anything else, the underhood area has been seein a lot of water here lately, so i'm wondering if it screwed up the alt. I have my voltmeter hooked right to the coil plug in, that way the custom guages only turn on when the ignition is on, so I'm wondering if the voltage spikes are only going to the ignition system, cuz u think that would blow all my fuses.
It's an 86 F-150 4x4 w/ a 300
It's an 86 F-150 4x4 w/ a 300
New User
Joined: Aug 2004
Posts: 20
Likes: 0
I have to agree with 5_labsownus. I just replaced mine on my 86 F250. Problem gone. Good luck. My regulator was on alternator so I just replaced the whole damn thing. Get this I think it was the original alternator. The brushes were shot too but still showed good when I tested it. I was amazed actually. but hope you get it fixed
James
James
FTE Chapter Leader
Joined: May 2002
Posts: 42,687
Likes: 3,153
From: Fraziers Bottom, WV
I've seen both styles of alternator run for months to years with no brushes Just the spring and the contact cable. What gets most old and weak alternators is spinnind only a half turn backwards or water!
Thread Starter
|
Elder User
Joined: Jul 2003
Posts: 997
Likes: 0
From: Weston, Nebraska
Yeah this is still the original alternator and has quite the workout at nite, I have running and clearence lights everywhere and like 6 offroad lights and the stereo, subs and amp, plus the head lights, I'd say it does pretty good. It really cranks that guage and if those double belts ain't extremely tight the'll squeal. But man I've had no luck w/ rebuilt starters and alternators, it's hard to get a good one even if they are lifetime warrenty. Right now I'm in Automotive Tech School and next week were going over rebuilding starters and alternators, right now were tearing manual trannys apart, so maybe I'll wait and see if I can just put in a voltage reg. myself, but if I get it apart and it's wore out, well... new one I guess. I kinda thought it was a voltage reg. but it's always better to ask cause sometimes it's something stupid.
Trending Topics
Elder User
Joined: Oct 2004
Posts: 984
Likes: 0
From: Winnipeg, Manitoba
You say you've seen a lot of water lately. I had an interesting problem a few years ago that was causing all kinds of grief in regards to taking out batteries, ignition, and a few other parts. Ended up being corrosion on the little white plug that connects to the alternator. Remove it, and clean the terminals on both the alternator, and the plug. See if this cures it. Coat the end of the plug with a bit of di-electric grease to regain water proof connection afterwards.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Top 10 Fords at 2026 Carlisle Ford Nationals
Joe Kucinski
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Thread Starter
|
Elder User
Joined: Jul 2003
Posts: 997
Likes: 0
From: Weston, Nebraska
Yeah, I think I'll try that. I didn't really think that could be a problem, since I'm gettin more voltage, you think that if it was shorted, corroded or grounded you would get less or none, but I'll fiddle around with some of that wiring and see if I can find anything.
Elder User
Joined: Oct 2004
Posts: 984
Likes: 0
From: Winnipeg, Manitoba
Overcharge will show with a simple bad ground, or a battery that is on it's way out. The extra voltage has to go somewhere, and in reality, DC current runs ground to positive, not the other way around, as is commonly thought. If you're serious about the load you put on your alternator with extra lights, add a relay and circuit breaker to each of them, and ground them directly to the alternator casing, as this will make for reduced draw on both battery and alternator, and free up some juice for other electrical devices.(Theory is used in fact on fiberglass body vehicals such as fiberglass body jeeps, etc, aftermarket stuff mostly) No grounding points on a fiberglass body, except the frame, or the alternator case itself) One thing as well, to check. Is there a ground wire from the engine block to the body? If not, add one, you'll amaze yourself as to what that addition alone can do.
Thread Starter
|
Elder User
Joined: Jul 2003
Posts: 997
Likes: 0
From: Weston, Nebraska
Relays are used to reduce a load on a switch, they still draw the same, a circut breaker will just break the circut if the load becomes to much and save your fuse is all, still draws the same. But that's not the problem, I was just saying the alternator does a good job keepin up, even now. Also it has never been discovered which way current actually flows, it proves to be efficent eithier way. Ford is actually switching back to positive ground (the electron theory) on it's bran new trucks, that'll make a mess of everything. But wirings all fine, just need to get the alt. toned down so it doesn't ruin my ignition system.
Elder User
Joined: Oct 2004
Posts: 984
Likes: 0
From: Winnipeg, Manitoba
Curious, have you put a volt meter to your battery while the engine is at idle, and then had someone rev it to, say 1200 - 1500 rpm? It should max out at no more than 13.5 to 14 volts at 1500 rpm, where the voltage regulator should cut it off. If it goes past this, your reg's gone south, and needs replacing. You might also simply have a bad internal(to the alternator) rectifier, which is basically the internal part that your wires connect to, inside the alternator. It ends up being a smallish white plasitc part with electrical connections inside of it, and not to hard to change if you're brave enough to take the alternator apart. To give it a short term test, there's a hole on the back side of your alternator,near the top where the plug is. You can stick roughly an 8 gauge bared hard wire through it, and full field your alternator briefly. If this settles the voltages down, it's your problem. I wouldn't recommend running the truck this way long...it's an "it'll get you home" type fix, but needs to be looked at ASAP!
Edit: More here.
http://smccd.net/accounts/mcafee/Lab...nosisWork.html
Edit: More here.
http://smccd.net/accounts/mcafee/Lab...nosisWork.html
Last edited by RR4E; Dec 3, 2004 at 06:48 AM.