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A. Penland
A. Penland, Ford Senior Master Technician, ASE
Category: Ford
Satisfied Customers: 6641
Experience:  ASE Master Certified, ASE Advanced Gasoline Engine Performance
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91 ford Ranger: alternator..possibel that the battery cables are bad

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I have 91 ford Ranger and the batttery will not charge. I have installed a new battery and a new alternator. Is is possibel that the battery cables are bad. If not where to a go from herrs? I have also checked the power distribution box and all fuses are good.

HelloCustomer

If you have a meter, I can walk you through a simple check to see what the problem is with your Ranger charging system.

Customer: replied 7 years ago.

 

I do have an ohm meter. Would it be better if we talk by phone? I have a cell phone .

The web site will only alow us to talk online on the web site. Phone calls are against website policy. But the test is pretty easy. Does the meter have a voltage setting for DC volts?
Customer: replied 7 years ago.

 

Sure does!!

Ok. Below is the wiring diagram for your chaging system. It you can print it out and take it to the truck with my instructions, you will be able to find the problem.

graphic

Start the truck and with the meter, check for voltage at the battery cable on the back of the alternator. It should read 13.5 volts or close to it.

 

Then with the truck running, check for power on the

ORANGE/LIGHT BLUE striped wire

BLACK/ORANGE striped wire

YELLOW/WHITE striped wire

They should all be around 12 volts.

 

Let me know what you have at each wire.

A. Penland and 3 other Ford Specialists are ready to help you
Customer: replied 7 years ago.

 

I have to install the battery so I can check out your answer This will take a little while. Will you still be available?

I will be on here for a while. Look next to my picture when you are looking at the question. It will say ONLINE or OFFLINE. But I will get an email if you post a response.
Customer: replied 7 years ago.

 

I get 13.volts at the Oraqnge and blue and the Orange and black .Also the same on the yellow and white.

What is the voltage at the battery terminals with the engine running? Also check the voltage at the battery with the AC, high beams and wipers on. It should go no lower than 12.8 volts.
Customer: replied 7 years ago.

 

Let me check....Be right back..

I'll be here.
Customer: replied 7 years ago.

 

The battery stays the same voltage remains constant. This happens as the truck runs on the battery with a full charge and it appears that all is well and then it is just running on the battery. One time the voltage indicator showed what look like it was charging for about two seconds and then dropped back to less that normal. right after that the truck went dead. Not enough charge to start.

I have charged the battery this evening so I have a good charge on it.

It is sounding like you have bad battery cables as you have already guessed. I just wanted to verify it with a simple test that I would do in the shop for the same problem. Poor connections and bad cables under the insulation plus poor grounds will cause all the same problems. Since your Ranger is a 1991, replacing both the negative and positive cables would be the way to fiix your problem. We found that the alternator is charging and it is just not getting the full charge back to the battery. Replacing the cables and cleaning the grounds will fix the problem.
Customer: replied 7 years ago.

The voltage did not go lower than about 12.8 volts with your suggestions.

The battery stays the same voltage remains constant. This happens as the truck runs on the battery with a full charge and it appears that all is well and then it is just running on the battery. One time the voltage indicator showed what look like it was charging for about two seconds and then dropped back to less that normal. right after that the truck went dead. Not enough charge to start.

I have charged the battery this evening so I have a good charge on it.

 

Thanks for al your help. I' get the cables in the morning. Thanks again

You're very welcome. Make sure the ground connections for the cable are clean also.