Help with no power??
Sometimes I think Mattox overcomplicates. The primary power in these girls is quite simple and failures fall into a small number of possibilities, especially with a major power failure A diagram you would do well to memorize is the one in the MAD article concerning ammeters
Catalog
Now people discuss and cuss this article, and I don't agree with some of the "cure" but there are very valid points. The primary power varies some from year to year, but in the cars with "full current" ammeters the path in question is fairly the same
That path, generally CAN FAIL at any of the following points. You simply need to check them all aout
From the battery, to the starter relay "big stud" which is used as a junction. ------from there to the FUSE LINK-----and through the BULKHEAD CONNECTOR on the RED ammeter wire, to the AMMETER----out on the big BLACK ammeter wire and to the WELDED SPLICE.
Each of those points in the path or MORE than one can has and does fail. Even the welded splice has failed in a few cars.
What to do?
Remove the connection to the fuse link and 'work' it and feel for corrosion/ melt damage inside, and inspect the insulation. Disassemble the sections of the bulkhead connector inspect and repair. This is likely one of the most failure prone.
Consider removing the instrument cluster. If not, "feel" up in the ammeter terminals for any looseness, or if/ when you get power, load it with headlights, heater power, etc, and feel for any heating up in there, or intermittent movement of the ammeter needle when shaking the wiring near the ammeter.
The ammeter in the 70 cars is particularly suspect for several reasons...........Severall years ammeters the studs are simply 'slipped' through the shunt/ guts of the ammeter and out through the PLASTIC cluster housing with nuts and washers. IF THIS assembly becomes the slightest bit loose, then it heats and the cluster plastic softens, causing things to get MORE loose, and fail
So far as the welded splice, there is likely no way to check it. If you have checked/ repaird the fuse link, the bulkhead connector, and the ammeter, and still have mysterious power problems, then unwrap the harness starting at the ammeter and follow the black to the splice a few inches away.
IF YOU have the cluster out, I would do that.
Sometimes I think Mattox overcomplicates. The primary power in these girls is quite simple and failures fall into a small number of possibilities, especially with a major power failure A diagram you would do well to memorize is the one in the MAD article concerning ammeters
Catalog
Now people discuss and cuss this article, and I don't agree with some of the "cure" but there are very valid points. The primary power varies some from year to year, but in the cars with "full current" ammeters the path in question is fairly the same
That path, generally CAN FAIL at any of the following points. You simply need to check them all aout
From the battery, to the starter relay "big stud" which is used as a junction. ------from there to the FUSE LINK-----and through the BULKHEAD CONNECTOR on the RED ammeter wire, to the AMMETER----out on the big BLACK ammeter wire and to the WELDED SPLICE.
Each of those points in the path or MORE than one can has and does fail. Even the welded splice has failed in a few cars.
What to do?
Remove the connection to the fuse link and 'work' it and feel for corrosion/ melt damage inside, and inspect the insulation. Disassemble the sections of the bulkhead connector inspect and repair. This is likely one of the most failure prone.
Consider removing the instrument cluster. If not, "feel" up in the ammeter terminals for any looseness, or if/ when you get power, load it with headlights, heater power, etc, and feel for any heating up in there, or intermittent movement of the ammeter needle when shaking the wiring near the ammeter.
The ammeter in the 70 cars is particularly suspect for several reasons...........Severall years ammeters the studs are simply 'slipped' through the shunt/ guts of the ammeter and out through the PLASTIC cluster housing with nuts and washers. IF THIS assembly becomes the slightest bit loose, then it heats and the cluster plastic softens, causing things to get MORE loose, and fail
So far as the welded splice, there is likely no way to check it. If you have checked/ repaird the fuse link, the bulkhead connector, and the ammeter, and still have mysterious power problems, then unwrap the harness starting at the ammeter and follow the black to the splice a few inches away.
IF YOU have the cluster out, I would do that.
