SO here is my problem. I have a 98 f150. I have the 4.6 and i dont have enough power. My battery is only 5 months old. ITs a duralast with 850 CC Amps.

My problem is that My truck wont roll down the windows and play the radio at the same time. It cuts out the radio to roll down the windows. THis is when the truck is off... IE the key turned to Acc. The same happens when i step on the brake pedal. The radio will cut out.

Everything is fine while the truck is running. My windows are slower than others with the same body style but they work and the radio will at the same time. I should say this now. I dont have my radio load or drawing a lot of power. THis happens when its on lowvolume and i dont have a sub.

When i drive long distances at night i can here a high whistle coming from somewhere when i use the power windows. After i have had the lights on for a long period of time.

I tool the truck to autozone and schucks and had them test it. Both say its fine. This has happened before and thats why i had got the new battery. But that didn't fix the problem. It only prolonged the problem.

When i drive my truck on the highway during the day time nothing is wrong.

Im thinking that my altenator isn't putting enough out and my battery cant keep up. But the ALtentors "TESTS" fine. Whatever that means.

What do you guys think. What should i do. Any tests? DOes anyone know of a high output altenator for our trucks?

 

It appears to me that you have a high resistance in a power distribution circuit that is supplying power to the window, brake lights and radio. When the window motor or brake lights draw a relatively large amount of current through the high resistance, the voltage drops and the radio cuts out. I would recommend connecting a voltmeter to the battery terminals while someone lowers the window just to be sure that the battery voltage isn't dropping, but I don't suspect it is since you didn't mention any starting problems. Actually touch the meter to the battery terminals, not to the cable connectors that connect to the battery. Then check a wiring diagram to determine what circuit is common to the radio, brake lights and window and track down your problem with a voltmeter while someone raises and lowers the window. It could be a high resistance fuse box contact, a high resistance relay contact, a corroded wire or a bad ground just to mention a few possibilities.

GOOD LUCK.

 

Have you had your truck in water lately, a lot of rain?
Follow Nkenn's advise and check the battery under load. If you dont have a volt meter autozone will loan you one.

 

Your definitely getting high resistance from somewhere. I would check the power load terminals that set on the firewall behind the plastic cover. You may even consider replacing those fuses; you will have to get them from Ford. I would then judging on your picture pull the wires off of the starter, clean them with a brush and reattach them and then seal them. NAPA sells a spray on sealant that should do the trick. Next to the alternator and clean the red wire and terminal on the alternator. As far as the wire that plug into the Alternator. just spray them with CRC's contact cleaner and put them back on. Where the power distribution blocks are make sure you pull them off and wire brush then also. Those big fuses can be checked for resistance before you have them replaced if you want. If after all of that is done and there is still issues, I would have the alternator checked at an electrical shop that rebuilds alternators and starters. There equipment is much better than a test at Advanced or the like.

You have no heavy current draw during the daylight nothing is on and the engine actually steps down the volts to 6 to run the engine. It is when the loads come on that you start to have the problems.

It wouldn't hurt to install an Amp meter in the truck after you get it fixed. Idiot lights show after affect and volt meters don't show the load, just what the battery has or if the Alt is putting out. Amps is what count

Good luck and let me know what steps you do and how it goes.

wayne

 

how would i go about testing those points. Where are they located. I know a ton about an engine but nothing about electricity.

 

OK
The starter is an easy one. Disconnect all the wires attached to it and clean them with CRC electrical cleaner and wire brush the terminals on the starter. The power distribution block, the main one, is on the fire wall next to the air conditioner evaporator. Pull the plastic cover off and disconnect the wires, spray with CRC electrical cleaner and wire brush any large terminals. The two large fuses are in there. They are screwed in at there terminals. You can loosen them and take them off. Just put a volt meter across them to make sure one is not blown then switch to resistance and see where it comes in at. Let me know the number and I can tell you if it is good. The alternator is easy too. Unfortunately it sits on top of the engine in a well like. Same thing here disconnect the wires clean brush and re-attach.

Let me know how it goes.

Wayne

 

one other thing you might take a look at is you cab ground.this is generally a braided cable bolted on the back of the engine and connected to the firewall.these are bad to rust up especially if your truck is subjected to a lot of mud and water...also check you wiring harness ground located on the battery terminal.if either one of these are losing connection it may cause problems similiar to yours..

 

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I will check these in the morning. Grounds sound like what it could be as you can see it is subject to a little foul play

 

Well....

I spent some time last night under the dash. I found another thing that happens maybe it will help diagnose it. When you open and close the doors there is a relay under the dash(i cant find it so i dont knwo what all its contected to). Every time you open and close a door it clicks several times. Also when you roll the window down and it loses power. The same relay clicks and turns all the power to the radio and windows off.

The problem is at its worse right now. I had everything off and the key out and tried to roll 1 window up and it would only go about 3 inches and then would lose power. I would have to let go of the switch and then push it back down and it would move a couple more inches.

Im just about to take it to ford.

THe starter i just had off. Like less than 5000 miles ago and cleaned the wires so i know there ok. Next to the altenator. The problem is non existant while the truck is running so i would tend to rule out the altenator.

wdibert

Do you have a pic of the fuses. I tried breifly to look for them and couldn't find them. Are they in the main power distrabution box? Maybe i just have to look closer.

I am goign to change and spend some more time on her today. Any more ideas?

The truck isn't even getting enough power to keep that relay closed. WTF

 

Ok..... So i found the fuses. I was looking on the wrong side of the truck. LOL

How do i get them out? I pulled the cap of and there was some foam inside. Pulled the foam off and there was the fuse. But i cant figure out how to pull it.

 

If the alt is bad or about bad it will cause the batt to get drained tryn to keep up.Before you dig in to deep check the basics that are easy to find and test.
Put a volt meter on the batt with the truck off.Then put the volt meter on the batt with the truck running.Write down the readings and post it here.

If the truck is fine when its running I would not think a fuse or relay would be the cause.The same fuses and relays are inuse when the truck is running so if it were those things it would be an issue all the time.I would think the alt is at the cause in some way unless you have a voltage regulator that is separate from the alt.

 

I have had two differnt automotiv shops test the altenator b4. Thats what i thought at first. THey bot hsaid it was good. I will buy a volt meter today and post the results of the test today.

 

I had a 2001 ranger that did the same thing to me.Under the dealer warr I took it in 4 times and they told me it was fine the old no problem found deal.I put a volt meter on the batt with truck off it was 11.4 volts witch is low.With the truck running it was 13.1 witch is low.I picked up an alt off ebay for $100 and when installed I had 12.4 with truck off and 14.4 with it running and never had another problem.

After talking to powermaster and local alt shop it seems that an alt can make good voltage but not produce the correct amount of amps.Both places said the only way to do a good test an alt is to take it off the motor and test it in a machine at the shop.There are simple tests you can do to check the charging system that will tell you alot about what is going on but you need a volt meter.

 

Ok. For craps and giggles i pulled the altenator. Im heading to the wonderful(right?) autozone. GET IN THE ZONE. LOL anyways im guna have them test it and then go from there. I will post my results.

 

Check the ground cable from the battery going to the starter bolt, the frame and the body. The clicking when you open the door is from a weak power source or bad ground. You state that the battery is good so that leaves the grounds. There are also grounds behind both the driver and passenger side kick panels. If they are loose or corroded they will cause the clicking.

JMC