87 Ranger V8 swap gauge questions

[Bird76Mojo]

I don't currently have either the bk/o wire or the y/w wire coming from connector c109 hooked to anything, though I did try a few times before.

From c109 it looks like I need the y/w wire hooked to the battery + and the bk/o wire hooked to the alternator but im not sure which wire on the alternator. It's a stock 92 Thunderbird alternator.

 

[Bird76Mojo]

It's looking like the "A" terminal on the alternator will be used?

 

[RonD]

What alternator are you using?

2G alternator should have B+ to battery(fused), this is the big wire, B+ is the stud/nut terminal, 75amp
"A" to battery(fused), 15amp
"S" is the jumper wire back to alternator
"I" is the ON/OFF switch, needs 12volt, but key on ONLY or battery will run down

AMP gauge is not part of this nor does it make alternator work or not work, its not the same as battery light setup

AMP gauge wires are added to the B+ wire, i.e. B+ alternator to battery wire, to monitor direction of voltage on that wire, from Alt to battery is Charge, from battery to Alt is Discharge

From your diagram looks like you need to find the red/orange wire and yellow/light green wire if you want to hook up your AMP meter

These wouldn't be part of a 3rd party wiring harness

 

[Bird76Mojo]

It's the stock 1992 Thunderbird 5.0 alternator.

I've looked over this EVTM diagram until I was blue in the face, and tried a few combinations of testing, but my testing wires may be too small. The alternator is still charging the battery. I know that much for sure. Confirmed via voltmeter.

I'm using a Ron Francis Telorvek wiring harness with their add-on alternator harness.

I should be able to tie this system in to the factory amp gauge. That gauge does indeed show discharge when I have the blower motor turned on, etc.. I juts know I'm over-thinking this or missing something super simple.

 

[RonD]

If AMP gauge moves then its hooked up to something
It has no wires connected in the cab, both should be out in the engine bay

I think 1992 should be 2G

Do your plug-ins look like these so no Stud/nut terminal: https://www.fuelinjectedford.com/public/alternator/2G-ALT_plug.gif

 

[Bird76Mojo]

If AMP gauge moves then its hooked up to something
It has no wires connected in the cab, both should be out in the engine bay

My alternator connector does look like that. Well, close enough. I have the Ron Francis 3G kit.

Alternator Harness for Ford 3G

Complete Alternator wiring kits for when you swap an alternator or simply need to wire up an alternator. Comes with 10 ft of 6 gauge GXL wire and necessary wiring for regulator.

www.ronfrancis.com

My problem is that it will only show discharge. Otherwise it always stays right at zero or slightly below.

So far I been driving it for a couple years with just the following: I have the BK/O wire from C110 (C110 is a single wire connector) coming from the cab hooked directly to the positive terminal on the starter solenoid. That's also where I have the large charge wire coming from my alternator to charge the battery.

I'm hoping by posting these comments, something will eventually click in my brain. lol

 

[RonD]

Wiring kit looks OK but larger red wire replaces Black/Orange wire as the B+ wire

So there should be no black/orange wire unless you didn't use the large Red wire

And there should be a fusible link between starter solenoid(relay) and the black/orange(red) wire

Find the AMP meter wires, red/orange wire and yellow/light green wire


Oh, and look for a Black/blue stripe wire while your at it, that's for Temp gauge, any Ford temp sender will work, just may not have same connector

 

[Bird76Mojo]

Wiring kit looks OK but larger red wire replaces Black/Orange wire as the B+ wire

So there should be no black/orange wire unless you didn't use the large Red wire

And there should be a fusible link between starter solenoid(relay) and the black/orange(red) wire

Find the AMP meter wires, red/orange wire and yellow/light green wire

It's my understanding that the R/O and Y/LG are behind the dash. I should be able to make the connections under the hood without getting behind the cluster at all. The BK/O and Y/W are both under the hood on the drivers side inner fender, and I don't have them hooked to anything currently. I do have the BK/O FROM C110 hooked directly to the + at the starter solenoid, but in connector C109, I'm not using either BK/O or Y/W wires.

So, according to the diagram above, I've got the battery side (left side of diagram) of the circuit connected since the BK/O from C110 (single wire connector) is hooked directly to the solenoid.

It's the middle/right side of the diagram that I'm lacking I think.

It seems like I need to hook the Y/W wire from the cab connector C109 to the alternator AND the BK/O from C109 to the battery + at the starter solenoid..?

I need professional help.

 

[Bird76Mojo]

One thought... If I could convert this gauge to a voltmeter, then that would be acceptable. Though I'd have to have an overlay made for the gauge face. I see they make similar things for the older F-series trucks.


I'm betting that I've removed the shunt when I removed the factory 4cyl alternator wiring, and that's my entire problem. Especially since the gauge does read a discharge condition. I know the old Ford F-series trucks had the shunt in the alternator harness. I'm betting the 1st gen Rangers were exactly the same.

 

[bobbywalter]

I used to have two ammeter for monitoring my glow plug banks. But....they had built in shunt.

Trace out your wires from the gauge so you know where they go exactly. I would just put it inline from the alt to the battery with new wire direct from the gauge harness at the cluster with fuselink wire as the separator for the drop....basically what it was....or just make your own backwrap shunt..

 

[Bird76Mojo]

I used to have two ammeter for monitoring my glow plug banks. But....they had built in shunt.

Trace out your wires from the gauge so you know where they go exactly. I would just put it inline from the alt to the battery with new wire direct from the gauge harness at the cluster with fuselink wire as the separator for the drop....basically what it was....or just make your own backwrap shunt..

OR you could just drive to Illinois and fix this thing for me!!

 

[bobbywalter]

We have two rigs out there for peoples gas .. but I am stuck in mid east Ohio right now. I need to go home and get my bronco so I can cage it up enough to go to Moab....you will have to come to me.

 

[Bird76Mojo]

Maybe someone will fix it for me at the Ranger meet-up later this year. Maybe Dirtman

I've been doing some reading on these old Ford shunt style ammeters and apparently you can't put them inline. If you do they'll blow.

 

[bobbywalter]

It probably works fine.

What is it charging at? 14.2 after crank and falling to 13.8? They don't usually move much unless your cranking 15 plus v.


Discharge the battery with the lights for an hour....then start it up and see where it swings to

 

[RonD]

The red/orange wire and yellow/light green wire are in the cab but would HAVE TO have been out in the engine bay for the amp meter to work.

No, on "changing" the Ranger Amp meter to a Volt meter, way way easier to just hook amp meter up, or just buy a digital volt meter and plug it into the Cigar lighter, seen here WITH USB hook ups, lol: https://images-na.ssl-images-amazon.com/images/I/51rM0Hd8LLL._AC_SL1100_.jpg
Or hook one up under the dash