So after doing a search I’m left with more questions than I had before.

I have a 2003 Ex V10 4x4, the dealer I purchased my reman OE alternator from said it’s 110amp but I read on another thread where someone said all V10’s have a factory 130amp alternator.

I have had some interesting (not really) power issues.

Most recently, while towing our travel trailer, the truck battery has been completely drained. First day out the trailer batteries (2 6volt) were pretty dry so when I noticed the issue, I replaced both house batteries and the truck battery. I assumed were pulling too much from truck and didn’t notice an issue after replacing the batteries. Then today almost home, abs light would come on when I turned the headlights on, once turned off, abs light went out. As long as RPMs were up truck was fine. Got home, pulled the trailer in and as soon as truck idled, it quit...

Previously the battery had issue when kids had their iPads charging after the lights were left on for a couple hours. After that occurrence, I pulled off, shut as much electrical off as I could and let the engine idle for 30 minutes or so and had no issues since until towing.

So now I’m here doing the research, I know there are wiring issues that can occur so I’ll check charging relays and the wiring from the alternator, but if the alternator is bad, I’d like to look into higher output.

I found this part number in the V10 forum: P/N 4C3Z-10346-BA, it’s a 140 amp, has anyone put this in the Excursion?

Any other suggestions for higher output alternators? Found this one:

https://www.power*******s.com/prodde...310-220-HD36-1

Any help is appreciated.

 

my tactic would be to figure out and resolve the issue and it is not that the alternator is not putting out enough amps. get one if you want but you havent really described anything indicating you need one

verifying the charge circuit wiring would be my first step. both positive and negative side and dont forget the troublesome fusible link as well as the plastic connector at the back of the alternator.

 

Continuity between alternator and this battery connection is good, these fusable links see to be ok.

 

This is my he first time I’ve really ever chased down something like this so bear with me. There is another fusable link on the driver side fender well, how do I check this one?

 

Also checked 2 wire grey plug and there seems to be continuity between the fat orange/green wire and alternator charge wire. Is this normal?

 

what is the voltage drop from the alternator to the battery end of the charge wire?

continuity doesn't indicate it is fine unless you know the resistance.

dont forget all the grounds which if i recall correctly there are 3 in the engine bay on your ex
(check the factory wire manual to verify )

 

@projectSHO89 is the resident electrical guru but not always here. search his post for great tips and hopefully he can chine in here.

 

voltage at the alternator is 13.7/13.8 and 13.5/13.6 at the battery terminals.

i cleaned all the battery connections, but I’m wondering if the alternator should have higher voltage?

 

It’s been running for about 20-30 minutes and voltage at the battery has dropped to 13.3 and 13.5 at the alternator.

 

So after cleaning all the connection points, I think that may have been the issue.

I checked wires from gray plug and grn/red gets 12.9 when the truck is running, org/green only gets voltage when truck is off. Battery is reading 13.3v after running for 30 minutes or so.

So, if the voltage readings are normal I think it was the dirty terminals, if voltage is low, what now? Is the alternator bad?

 

While 12.9 should be adequate, it does seem on the low end to me.

I have gone with DB Electrical for the last decade (can be found on their own website, amazon, or ebay, and maybe elsewhere)

I have not had a problem with a single alternator I have purchased from them, none have failed yet and the oldest one is about 8 years old now.

A decently running alternator should be around 13.6V-14.8V, above that is gonna fry stuff, below that may be to weak to meet running and charging demands.

 

That is abnormal. The orange/light blue wire is the battery voltage sense circuit and should always read battery voltage.

The light green/red wire should be powered when the ignition switch is in RUN or START. With the ignition switch in RUN and the engine not running, you should read 1-3 volts and the battery light int he cluster should be on. With the engine running, you should read 8-9 volts, the battery light should be off, and the analog gauge should show an indication proportional to the actual battery ( plus alternator output) voltage.

Voltage readings assume 1) negative meter lead on battery negative terminal, 2) good ground circuit between alternator case and battery negative terminal, and 3) that the positive meter lead is back-probing the connector pin and everything is connected.

 

thanks for the input guys!

projectSHO89, I’ll double check again based on what you said, I’m not sure I got the meter lead into the orange wire enough to make a good connect.

also, I was hoping you’d comment on the voltage I’m getting and if it seems too low. I have a good ground connection from negative battery cable to the alt case. If everything is functioning what should charging voltage of OE 115amp alternator be?

thanks for you patience!

Hans

 

You've already cleaned the connectors, but make sure you clean them really well (wire brush and/or baking soda & water solution). Apply a small amount of dielectric grease to slow any corrosion building back up.

 

Yes sir, cleaned well with wire brush and added dielectric grease as suggested.