Ford 8N - Electrical problem. No juice and ammeter buried into negative side.

[tmac196]

has your amp meter have 2 screw terminals or does it have a clamp on the back for a wire to run through it? my 8n had a clamp and a wire ran through it. came from the factory that way. replaced it several years ago with the 2 screw terminals type. just unscrewed the wire that ran through the clamp and put it on 1 of the terminals and put another wire on the other terminal and run it to where i unscrewed the first wire. has to be on the right terminals to get the hand to show discharge or charge in the right direction. also it never did show a lot of charge or discharge like the newer vehicles do now but the battery stays up good.
kydick

My ammeter is the two terminal type. Wires were reconnected exactly as they had been previously after replacement.

 

[tmac196]

Have you changed the regulater since you changed the Alt meter? Is it a 'known good'?

By "Alt meter" do you mean ammeter? If so, then no, I have not. Both parts are new (see post #28), but the ammeter was installed after the new vreg was installed.

Is the vreg a "known good"? Good question. It was the only one the gennie repair shop had left and it was handed to me bare without a box or instructions. There are no identifying markings on it so I don't even know the brand.

 

[Soundguy]

do a motor test. tell me what it does without the field hooked up.

 

[Soundguy]

By "Alt meter" do you mean ammeter? If so, then no, I have not. Both parts are new (see post #28), but the ammeter was installed after the new vreg was installed.

Is the vreg a "known good"? Good question. It was the only one the gennie repair shop had left and it was handed to me bare without a box or instructions. There are no identifying markings on it so I don't even know the brand.

were the tabs identified so you could hook it up?

was it actually an A circuit vreg?

look at the underside. there should be a bias ressitor from field to ground.

post back

 

[tmac196]

do a motor test. tell me what it does without the field hooked up.

Power to ARM, FLD wire off and leave ground intact, correct?

 

[tmac196]

were the tabs identified so you could hook it up?


was it actually an A circuit vreg?

look at the underside. there should be a bias ressitor from field to groun

post back

The tabs were identified, yes.

A circuit? I will call the shop and talk with the tech to find out.

There was a connector which appeared to be a resistor connecting two tabs in the back, yes. My recollection is that they were FLD and BAT, though.

 

[tmac196]

The tabs were identified, yes.

A circuit? I will call the shop and talk with the tech to find out.

There was a connector which appeared to be a resistor connecting two tabs in the back, yes. My recollection is that they were FLD and BAT, though.

Update: I spoke with the tech just now, it is an A-circuit vreg.
The connector on the back runs between the FLD and ARM terminals, so he says.

 

[Midniteoyl]

When you have an "A" circuit type voltage regulator means full power is sent to one brush while the voltage regulator controls the output by varying the ground to the other brush. It does not matter which wire you run to the regulator field connection and which one you ground, you can swap them around.

 

[Midniteoyl]

opps.. hit send too fast..


Anyways, best thing to do is start all hooked up then when the ammeter (alt meter ) is pegged to the left, lift the Grd wire from the Vreg. If it moves to the center, you've found the problem. If it stays, lift the Regulator (FLD) line and see if it moves. If it does, then the problem is again the Vreg. If not, there is a problem between the Vreg and the Generator. As I said above, the only difference (that I know of) between the first pic and the last is thast the Vreg is hooked back into the circuit. This points to either it being bad, again, or its wired incorrectly.

You could do more testing with a good sweep type VOM (non-digital) but I dont know if you have one..

 

[tmac196]

Update:


SG,

Gennie will not motor without the field hooked up.