Very Strange Electrical Problem

[jtfannin]

I have a 93 XLT with 64,500 miles. Battery is 6 months old, never had any problems with it. Recently, I have noticed that the lights inside and out flicker with the engine rpm fluctuations while idling- but not all the time. This morning when I went to start it up, absolutely nothing happenned. I turned the key on and off a few times, and after about three times, it started like nothing was wrong. On the way to work, I noticed that whenever I tapped the brake, the voltage gauge would bounce down and then back up, and when I was cruising at a constant speed, the gauge would dance very slightly. When I got to work, I shut it off, and it took two or three key on and offs to start it again. Also, sometimes when I turn the key from off to accessory, it takes a couple of seconds for the clock and other electrical stuff to come on. Usually they come right on. I'm stumped. Any ideas???

 

[aldive]

I would check both the battery as well as the alternator.

Good luck.....

 

[jtfannin]

An addendum to my earlier post - I just took it out and now the voltage needle is all over the place, and when I pulled out and my antilock motor kicked on, the engine almost died. Then when I shut it off, no start until three or four tries.

 

[dogfriend]

I second Al's suggestion. When you have a bad cell in a battery, it will drop the voltage because that cell no longer contributes anything (but resistence in the circuit). If you drop below about 10 volts, you don't have enough voltage to supply the PCM, so it won't crank or do anything. This happened to me a couple of times on my 89 Ranger. It used to eat batteries.

Also look for loose connections or corroded battery cables.

 

[aldive]

Further, put a REAL voltmeter on the alt output.

 

[BuPa]

Alternator

My 92 did that, I had the battery checked and it was OK, so I drove to my local auto electric shop and they pulled the alternator. The regulator was bad and so was the stator, one phase burnt out. The also put in a new brush holder assembly and new bearings. The regulator they put on was Motorcraft and the total bill was $79.00, we have no sales tax in Oregon.
Hope this helps.
BU

 

[Rkan121]

I currently have the same problem except mine wont start on its own at all. I have to carry an extra battery and jumpers just to start. I suspect it is the alternator possible the battery or terminal/wiring. I just put a new starter and cleaned the termals.

 

[Opera House]

Loosen and retighten

the connections of the starter solenoid on the fender. This is where the main power takeoff for the car is. A bad connection there can cause this. Another common problem is the ground connection from the engine to the car frame. Remember the engine electrically floats and without this, the only grounding is through bearings. It is not uncommon for electrical problems at the end connections of battery cables at this age.

 

[Pendarus]

Mine did that about 6 months ago. Turned out to be a bad cell in the battery combined with a bad starter solenoid. (Or so they told me, I think the battery was OK but they "Recycled" it before I could get it back and test it)

It would take 3 or 4 tries of the key to get the truck started, or I could leave the key on for 10-15 seconds and wait till the radio came on then start it. After a while I could not even jump start it any more.

 

[jtfannin]

Another strange experience - I had the alternator and battery checked last night - both OK. I had to replaced the starter solenoid - I broke a stud off tightening up the connections. Ran good after that. This morning, I took it out, and after running about 15 minutes, shut it off. Wouldn't restart for about another fifteen. I did notice that I had a very weak battery when the key was in accesory position, then lost all voltage when I turned the key past off into start. I checked all connections at the battery and solenoid, and noticed that the positive battery wire cinnection (not the battery terminal - just the clamp) was super hot. The negative was OK. Stared at it a little while, got in, and then it started right up. When I got home, the terminal was a decent temp.???????

 

[aldive]

When battery was checked, what did threy do?

What was the output voltage of the alt?

 

[dogfriend]

Originally posted by jtfannin
. I checked all connections at the battery and solenoid, and noticed that the positive battery wire cinnection (not the battery terminal - just the clamp) was super hot. The negative was OK. Stared at it a little while, got in, and then it started right up. When I got home, the terminal was a decent temp.???????

High temperature in electrical wiring means one of two things: Excessive Current or Excessive Resistance.

Either you have a shorted wire or component or you have a high resistance connection

I would first suspect a corroded connection or positive battery cable that is causing very high resistance. If you can, measure the resistance of the battery cable with it disconnected at both ends. It should be low resistance because its a large diameter cable.

 

[Opera House]

That could be dangerous!!!!!!!

Obviously the problem is a corroded post or a bad crimp on the wire. An experience I had with my 92 also indicates this is a safety issue.

My battery clamp cracked and causes an intermitant connection. Every time the connection opened up, a spike was created, the computer would signal to the IAC to open up and the rpm would jump to 2K. This is quite a shock when your foot is lightly on the brake at a stop and the car lurches forward. Evidently the computer resets, thinks you are starting the vehicle, and opens the IAC.

 

[Brandons]

I checked all connections at the battery and solenoid, and noticed that the positive battery wire cinnection (not the battery terminal - just the clamp) was super hot. The negative was OK. Stared at it a little while, got in, and then it started right up. When I got home, the terminal was a decent temp.???????

How tight is the clamp thing for the positive on the battery post? Cause if its really loose, could be arcing, which would make it friggin hot.

And im having almost the same problem except i can start the truck just fine without problem. When i switch to accesesory the clock takes about 3 seconds to turn on, and when its idling the lights will flicker, and when i step on it the lights brighten. Also my CD Changer wont start unless the truck is on, acessory just makes it turn off then on, then off then on, and off again. I think that is because its not getting enough voltage to start the changer. Course its also 9 years old.. . would this probably mean my battery is toast? should i steal the one out of the other car and give it a test shot?

the connections of the starter solenoid on the fender. This is where the main power takeoff for the car is. A bad connection there can cause this. Another common problem is the ground connection from the engine to the car frame. Remember the engine electrically floats and without this, the only grounding is through bearings.

And could you go a bit more in depth about how to tell how well your engine is grounded? this might also be a problem for me, considering i live in canada were in the winter, things rust away.

 

[dogfriend]

Originally posted by Brandons




And could you go a bit more in depth about how to tell how well your engine is grounded? this might also be a problem for me, considering i live in canada were in the winter, things rust away.

As a first test, measure the resistance between the neg terminal and the engine. There should be very low resistance between them (the engine should be at ground).

If is looks corroded, it probably is

 

[Brandons]

hmm thanks! il give it a shot, or wait till it messes up either way

 

[01EB5.0]

me too

I too have a strange electrical issue. While on vacation last week in the Upper Peninsula of Michigan, i had to travel about 100 miles total on gravel or sand roads. the gravel was washboard in many places and thus was vibrating the truck like crazy. In the morning I drove the gravel road to get out of the park (about 25 miles total) then drove back south. i was on the road for a good 300 miles and I notice my battery gauge is creeping higher and higher. Eventually it is nearly to the top of the "normal" band and then my battery light comes on. When I would stop at a stoplight, the battery needle would fall to the lower 1/3 of the normal range (this is where it normally hangs out) and the light would go off, then I hit the gas the gauge shoots up and th elight comes on. I don;t know if the gravel roads have anything to do with this problem, but it is the only thing i can figure. the truck only has 64,000 miles and the battery was replaced about a year ago with a new motorcraft battery. Everything seems normal except for that high charge indication. Because of that, we stopped at a hotel for the night and I took it to a ford dealer in MI the next morning. Sure enough, the light was not on that morning, but the guy still hooked up his hand-held charge system tester. He said the battery was good and the charging system was good. He said the voltage reading was between 15.5 and 16.5 Volts, which he did say was a little higher then what he normally sees, but he said it should not cause any issues unless it gets a lot higher. i have an appointment to bring it to my local ford dealer Monday, but if the light is not on I don; tknow if they will do anything. Anyone else ever had this high charge rate on ther explorer?

 

[Skeets'91EB]

Okay this is a lot, but its the best explanation I can give, please read!

I have a srange problem as well. I put a new throttle body on my X last night, and in order to do so, the stock air tube has to be removed from the stock tb. I removed it and moved it away from the engine, and the tube was moving electrical wires and the kkm hit the power distribution box a few times. I dont think this could've hurt the wires that much though.

When I was all done installing, I reconnected the stock tube and reconnected the ground terminal. I started the car to let it idle so the computer could relearn air/fuel requirements. I was going to take the X out for a spin to test out my new tb. I turned on the headlights and I noticed the volt gauge danced around a bit. It was very sensitive to any electrical fluctuations. I put on the brakes and the headlights flickered, and the engine rpm dipped a bit. I then put the X in Reverse, and then, the engine and the electrical system ENTIRELY shut down . (The garage was dark and it was night outside so when everything went down, it was really dark, it was as if the power went out in a city .) I turned the key again...nothing. Anyways, I opened the hood and wiggled the negative terminal, just slightly. There were a few sparks (like when you reconnect it) and the power came back on. I tightened it down just to be sure.

Next, I took a drive (everything was fine and normal), stopped by a friends house for a bit, and when I came home, the problem arrose again. The volt gauge was extremely sensitive and responded to any electrical demand (brakes, shifting, headlights, steering, stereo).

A few months ago, I was having a problem with the alarm and electrical system acting up on me, but it wasnt quite like this. I just cleaned off a lot of corrosion and it was fine.
This time however, there isnt a lot of corrosion on the terminal, and I even installed some of those anti-corrosion spacers a few weeks ago. I just dont understand why it started messing up like this right after and not earlier that day before I had installed the new tb . However, I'm 95% sure its gotta be a bad negative terminal, so I'm off to buy a new one...

 

[Billy177]

check your grounds and try wiggling your battery cables

 

[01EB5.0]

SOunds like your battery cable is bad..they are notorius gettng corroded on the inside and failing on the early explorers