Voltage dropping intermittently

[CaseyJones]

I drive home at night and notice the voltage dropping every little while. Everything dims and the needle sits on the red. It will return to normal for a minute or two, then back down........up........down......up.....down every minute or so.

I found a thread in the archives that described same symptoms and cured by cleaning up alternator terminals. I did that to no avail. Any other ideas what this might be?? Im stumped!

Might this have anything to do w/glowplug controller? Cold starts are a ***** and I have 8 motorcraft/Beru plugs coming monday at which time I will immediatly swap them out (hoping for no problems there as previos owner had SOME of the glowplugs replaced--not sure or brand or why only some).

89 F250 7.3, Banks, 5sp. AC, CC, 4x4, GV overdrive.

 

[OkieGringo]

Even after you install the new Motorcraft GPs , I'd highly recommend that you check the headlight switch and the wires going to it from the fuse block under the dash. The wiring is a known MAJOR problem which VERY often results in melted wires and FIRE. Go to this website and do the mod before it's too late. OkieGringo



http://www.ford-trucks.com/articles/delanty/brighter_lights.html

 

[gabbyr100rs]

Amen to what Mr. OG just posted!!

When I changed out my headlight switch and rewired the plug after losing marker, tail, and dash lights (installed a 20 amp relay, too), the switch and plug were quite melted and deformed--a couple of the wires were just toast from having been WAY to hot!

Good luck!

 

[sassyrel]

and if that dont solve it--replace the voltage reg--when they start to get funky--they do just that--or the brushes in the alt are getting wore--

 

[f-two-fiddy]

I'd suspect the gp controller.

 

[CaseyJones]

I tried to keep an eye on it today while I could drive w/o headlamps and I didnt notice it doing anything but flinching a little here and there but not to the extremes of nighttime driving.

I will pull the headlight mod since its a problem area anyway. Its one less thing Ill have to worry about in the future.

If it is the GP controller, can I unhook the controller before an evening drive to troubleshoot any ill effect it has on the charging system during operation? How to do this?

Thanks

Tony

 

[f-two-fiddy]

Try pulling the firing signal wire off the GP solonoid.

You stated that your burning GP's, that makes me suspect the controller.

 

[highest_vision]

Have you checked your body and engine grounds? You don't say where you live, but this is winter and if you live where the roads are treated, corrosion may have built up enough on a connection that wasn't tight enough or was falling apart. Loose connection, add in some winter corrosion build up, and you will have some electrical fluctuations and gremlins
Good Luck
James

 

[OkieGringo]

I tried to keep an eye on it today while I could drive w/o headlamps and I didnt notice it doing anything but flinching a little here and there but not to the extremes of nighttime driving.
I will pull the headlight mod since its a problem area anyway. Its one less thing Ill have to worry about in the future.
If it is the GP controller, can I unhook the controller before an evening drive to troubleshoot any ill effect it has on the charging system during operation? How to do this? Thanks Tony

You could put in a GP bypass Switch. If you'd like, I could email you a diagram. Is your email address in your Profile? OkieGringo

 

[CaseyJones]

I live in SD but just got the truck over Ebay from NE from original owner. He had some of the glowplugs replaced but not sure why only some. The WTS light works about 3 sec and is hard to start unless warm/plugged in. I have read that this is a symptom of GPs. Somehow I doubt he installed motorcrafts as crapolites are so readily available and cheap. Just checked all visible connections under the hood, all body connections are sound.

I dont know if the truck is eating glow plugs, I have read that if you dont replace them ALL or mix brands that they will quickly eat the good ones or at best not function correctly. The GPs will all 8 be replaced tomorow. The controller clicks and does everythign I have read it should. If I can figure out which wire has to be pulled to disable the GP controller Ill do it and try to eliminate it as the problem.

BTW, would love to have that schematic emailed to me. If I dont use it now I will print it out and keep it w/the truck. I seem to be prone to those situations where such things suddenly become necessary!

Updating my prof w/email info now. THANKS

Tony

 

[OkieGringo]

When I try to send you email the site gives me this message...

Sorry! That user has specified that they do not wish to receive emails. If you still wish to send an email to this user, please contact the administrator and they may be able to help.

You need to change the "preference" for this to work.

You can add a wire to the GP Controller terminal that has the small white wire terminal and run it to a momentary switch on dash and then ground the other side of the switch. This will allow you to push the button to activate the GP Controller or let it work automatically once everything is fixed. Just don't push the button tooooooo long. On really cold mornings I let the Controller do it's thing then push button a few seconds longer and it seems to help. OkieGringo

 

[Mikes91]

AMEN. DOUBLY. To what Okie posted.

I nearly lost my truck last month. I was THIS close to a cab fire.

I'd been having trouble with the voltage gauge briefly dropping to zero while driving, then back up to normal. Voltage regulator didn't fix it.

Checked the alternator, off the truck, and it was fine.

Headlight switch next step. Removed it. Burnt on the back of the socket. Pigtail wires burnt, and SEVERAL were melted TOGETHER. Copper wires touching. Kinda explains the flickering light problem I was having.

There could have been a cab fire at ANY time. I was lucky. The *********/red wire was melted, and the electrical tape over the connection was crispy from the heat being built up on the bad connection on that wire. Ford had redone those wires in 2004 after a meltdown on the road caused my A/C, cruise control, overdrive, etc. to stop working while pulling 10,000 pounds of horses. Wow.

Ford's terrible design.

My advice to you is to disconnect BOTH batteries AS SOON AS YOU READ THIS. Get a new pigtail, new headlight switch, and do the repairs like I did last month. Search on "headlight switch" and you'll see the posts where I learned how to do the repair the RIGHT way (not the Ford shop way). Do the parking light mod as soon as you can if you pull trailers so that you can get the load OFF the headlight switch, and do the headlight mod as soon as you can.

The fact that Ford put together such a poorly designed circuit amazes me. They knew people would be pulling with these trucks. I'm surprised that this crap flew. ONE PULL with my trailer, plus ONE PULL across country with a u-haul car trailer after the repair was enough to melt the connector. I doubt my headlights alone are sapping the system so much... probably also due to the Ford shop's fix last time this happened. They' twisted the wires together and covered with electrical tape instead of using butt connectors to get good, TIGHT, connections.

I'd be disconnecting those batteries about right now...

 

[Agnem]

Run with a voltmeter connected directly to both terminals of one of the batteries, to see if this voltage loss is real, or just in the wiring.

 

[CaseyJones]

I can see the voltage loss to be real because everything dims when the gauge drops almost to the red. I changed my checkbox to allow users to email me. not sure why it didnt work

thomas_4 yahoo com

hehehehe I hope this doesnt bend any forum rules

Im currently moving but in the next day or two I will locate my rather large box of VW/Saab/BMW relays and do the HI/LOW and now parklamp relay mods. I cant have any issues w/this truck because the only other cage I have is a street legal Manx dune buggy. Not good for this time of year!

Thanks all for the help. I plan to address all these weak areas in the very near future. Right now Im fretting the GP removal more than anything else. I hope sure as hell that they all come out nicely. After I get them in, if the GP controller is anything other than perfect I will immdeiatly do the mod, nobody else is allowed to touch my truck but me, the GP switch will be stached under the seat. hehehe

THANKS ALL

 

[OkieGringo]

There are acoulpe of ways to do this.

ONE: I added a wire from the WHITE wire terminal on the GPC and ran it to a momentary switch on the dash. Then ran a wire from the other side of the momentary switch to groung. This way I can push the button after the Wait To Start light goes out for a few more seconds to heat the GPs some more before I start. It'll still work automatically.

TWO: Take the WHITE wire OFF the GP Controller(GPC), and insulate it with tape. ADD a wire from where the white wire had come off, and run it to a Momentary Switch on the dash near the Wait To Start light,
from the other side of the Momentary Switch to a good ground.
Also cut the Blue/White wire going to the GPC and connect
that to the terminal on the GPC where the white wire was attached(you’ll now have 2 wires on that terminal), that will make the Wait To Start light come on when you press the button to glow up the plugs for however long you hold the Momentary Switch. If you don’t have Motorcraft Glow Plugs, I don’t recommend this procedure.

THREE: Go to www.webshots.com plug in my username (bajajeeper) and look at the uploads I have there. You'll find what you need.