Ammeter issue

[Michael M.]

I just replaced my ignition and forward lamp harnesses in my '68. Now my ammeter doesn't work and it was working before I replaced the harnesses. WHile I was working on the harnesses and vacuum hoses, the dash was pretty much dismantled to replace the wiper door solenoid, vacuum hoses and switches under the dash and fiber optics.

I have verified that the alternator is charging the battery.

There is no movement of the ammeter during starting, or when the lights are turned on or any other electrical load is placed on the system. It just sits there under all circumstances just a little left of -0-.

There is around 14.4v on both sides of the ammeter connections when the engine is running. I also used the AA battery method and verified full deflection in both directions when I changed the polarity of the connections. I'm stumped.

Could it be a grounding issue? Or would I not get 14.4v on both sides of the ammeter without a proper ground.

Thanks for any replies.

[Gene M.]

Re: Ammeter issue

Michael,
Your problem most likely is in the one of the connections at the bulk head connector on the firewall. Ya must have "upset" one connection for the amp gauge contacts. Corrosion must have inhibited connection and you being in there finished it off. A good cleaning of connections should get ya back in operation.

[Michael M.]

Re: Ammeter issue

Thanks Gene, from wiring diagrams it appears that both ammeter wires trace back to the horn relay through the bulkhead connector.

Would I get power at both ammeter terminals if the bulkhead connections were making proper contact? I'm just trying to figure this out. All of my other gauges work properly (except for the clock , of course, which hasn't worked in 20 years).

[Gene M.]

Re: Ammeter issue

Michael, I would ring it out with an ohm meter. Unplug the connector at amp gauge and disconnect wires at relay. Check each set of wires thru the bulk head connector to insure contact thru bulk head. You will need long jumper wires to reach both ends at once.

[Michael M.]

Re: Ammeter issue

Dave, it seems I checked it wrong. The ammeter was connected when I checked for voltage. I'll disconnect and then check the actual wires.

Gene, I assume you want me to check continuity thrugh the bulkhead connector. I will do so once I re-check for voltage.

Thanks to all so far. I may post another question or two. I will at least post the resolution if there is one.

[John H.]

Re: Ammeter issue

Michael -

The 16-ga. black wire in the connector goes through the bulkhead connector to the large battery cable stud on the starter solenoid (with a brown fusble link section at the solenoid terminal), and the 16-ga. black/white wire in the other cavity in the connector goes through the bulkhead connector to a screw terminal on the horn relay (with an orange fusible link section at the terminal).

[Michael M.]

Re: Ammeter issue

Thanks everyone for the replies. I fixed the problem and Gene was right. It was a bulkhead connector issue.

I checked the wires at the ammeter and only one of them had power with the engine running. I removed the bolt and separated the bulkhead connector and checked continuity from both ammeter wires back to the passenger compartment side of the bulkhead connector and they both checked out OK.

I believe that when I first re-installed the bulkhead connector that it was a little cocked and wasn't making proper contact. Once I made sure the connector was square into the firewall, I reconnected the engine compartment side and all is well.

Thanks again for all the help.