[jonfromhamilton]

Hey all, I am trying to diagnose why my EL, mitsi type alternator is not charging. I had run this for a while on my old sierra and worked fine now not so much.
I have a relocated battery behind the cab (trayback) which is not shorting anywhere I have tested it.
I have gone to the wrecker to get a new alternator and replaced it but that did nothing.
I have had someone run the mutli-meter across + and - while revving the engine still not getting anything more than 12v when the car is running which is what I am getting when the car is turned off.
So with my limited experience I would say BOTH the alternators are faulty because I can't think of anything else it might be.
I would expect to be getting 14ish volts if it was working correctly.

If I trickle charge the battery it stays charged so I am leaning towards it not being the batteries problem.
I have not yet actually taken the alternator to an auto sparky to test it I have just swapped out the new one and then back to the old one when it wasn't working either.

so basically I am getting 12.3v with the car switched off and a bit less than that with the car running.

If there is something I haven't checked for please let me know before I go off to the auto sparky to throw my cash away.

I discovered the issue when I spooled my rope back onto the drum of the winch and drained the battery so that was pretty disappointing.

Cheers

[Brenno]

Have you tested what the two wires are doing that come out of the back of the alternator? One is field voltage (12v reference) the other is the dash light. If it's not getting the reference voltage it won't charge so that'd be my guess.

[jonfromhamilton]

having looked on pirate4x4 there is a diagram and thread saying connect the sense wire to the battery positive but in that diagram there is a main isolation switch so i wonder if being connected to a constant when the car is not running if that will invite evil spirits to poltergeist my car

[jonfromhamilton]

another thread on here said to run it through a relay to ignition then to the battery to alt

[Gwagensteve]

Have you 100% confirmed the field and dash light wires are around the right way?
Have you 100% confirmed there is field voltage at the alternator?

Don't leave the field live when the car is off. The reason to drive the field directly off the positive is to reduce voltage drop at the field, so the charge voltage is correct. If you do this, run it through a relay that's ignition switched. That way the field isn't energised constantly.

I'm unsure if this is killing your alternator(s).

Steve.

[jonfromhamilton]

well im not 100% but it was running fine for a long time. the new(old) alternator was only in the car for 20 minutes while I tested the current then swapped it back

[Gwagensteve]

Despite a reputation for failing due to being filled with power steer fluid, I find Falcon alternators reliable and trouble free.

Are you trying to troubleshoot this without a multimeter that's going to make things really, really hard. Do you at least have a test light?

It sounded like you had this running correctly in your old sierra but not in this one. That being the case, all bets are off.

Are you sure you have connection from the charge lug of the alternator to the +ve terminal of your battery/car loom? I can't see your wiring - do you have an upgraded and fused charge wire from the alternator to your loom? maybe the alternator isn't actually connected to the loom at all.

confirm you have 12V at the field wire at the alternator.

When the car is running the charge light should be on, as you're not charging. Is this the case?

[Blkfxx]

Make sure the battery light (dash) is connected and operational. When Jake and I did the swap on his G16, we didn't have charge voltage despite having the relay setup. Swapped in a spare alt and still same issues until we realised cluster wasn't plugged in.

[Gwagensteve]

Subsequent texts have determined the charge light is not connected and there's all sorts of weird wiring behind the dash.

[jonfromhamilton]

i ran out of time so ill b going out tmrw to put 12v onto the light wire to see if thats it. if i pull the dash out again move the hazard switch because its awful on the steering column

[jonfromhamilton]

I put 12v into the plug at the white/red wire that plugs in to the alternator and got the battery light on the dash show up so the dash is plugged in.
When I plugged the alternator back in and turned each stage of the ignition, I got no battery symbol before the started at any stage
I also found that there was a short somewhere and isolating each circuit lead to finding there was a short between the two battery terminals so idk what is going on with that or if it would even affect the whole alternator exciting, charging thing in the first place.
I might have one problem (A bad battery) or two problems, battery and alternator circuit wiring.
I don't think there should be a short between the two battery posts (continuity with multi-meter) but that is just an assumption based on my no qualification to even own a set of spanners

[jonfromhamilton]

the charge light is connected and I was just joking when I said there was coles bags instead of wiring lol

[jonfromhamilton]

so on start up before i turn the key to engage the starter motor solenoid there is no symbol for the bettery lit up on the dash but if i put 12v into the white red wire [L] it does light up so it is wired and has earth.
I had the alternator out of the car but still wired and plugged in. i put some extension wires between the alternator amd plug spade connecters so i could put a test light on each wire. the Black/White wire [S] is connected into accessories so obvioussly it did light up but the other wire... the [L]light wire only dimly lit the test light so i wonder if there is not enough current to light the battery light in the dash?? and maybe that is effecting the alternator not charging.
Thoughts?

[jono165]

I have had 2 wrecker alternators stop working. I ended up just buying a replacement voltage regulator which was around $60. pulled the alternator apart, soldered it in and it worked fine ever since.

[jonfromhamilton]

ive jumped the light and sense wires swapped pins and everything im next going to take both my alts yo get them tested. pretty sure its thr alt now

[jonfromhamilton]

Jon where did u get urs?
https://www.ebay.com.au/itm/EF-EL-Ford- ... 1452632499
?

[jonfromhamilton]

took both alternators to an auto sparky who tested and discected them and he said they had both just been old and worn out

[fordem]

Does your auto sparky know what he's about?

What wears in an alternator are the bearings & brushes, both of which are replaceable items. There are a number of other ways for an alternator to fail - defective insulation, burned coils, failed regulator and/or rectifiers , physically damage, but old and worn out???

[jonfromhamilton]

yeah i will probably get the brushes replaced i think he just wanted to sell me a new alternator tbh

[jonfromhamilton]

installed a new regulator for $70 genuine mitsubishi one. put the lternator back together and now getting 14.4v