V12T
Well-Known Member
My ammeter and voltmeter suddenly went hard right and I'm trying to figure out why. I've seen a previous thread but my issue seems to be different. I've watched countless videos on alt and vr testing but still non the wiser. I have two alts. On the bench with the field direct to negative I get 15-17 volts on each measured output to alt casing. Put them in the car (still field direct to negative and vr bypassed) and I get 30-40 volts at the alt measured the same way. I have left the charge wire off to avoid frying the ammeter circuit. If I connect a fused wire from alt output to battery it blows a 30 amp fuse so multimeter is correct. I bought a new vr. Across terminals was 1.7 ohms. Now it's 0.69 ohms so I've probably fried it? Two old ones I have each read 9kohms so I guess these are useless. Earths and bulkhead connectors all good. Almost battery voltage at field. Are my alternators and vrs all broken? It seems a simple circuit but clearly isn't. I'm lost!
