Ammeter and washer pump issues

[Michael J.]

I am trying to finish up issues with my '66 L79 coupe. The ammeter is not working. I have checked the plug coming in, it has volts on one side but not the other, and idea where these two wires come from? The washer pump is not working and doesn't click, click when I push the button. Could this be an electrical problem and if so any idea where to look for it? Thanks for any help.

[Joel T.]

Re: Ammeter and washer pump issues

Mike;

I just did a quick look through my wiring diagrams... If you have a service manual for your 1966 they should be in there as well..

Looks like the connections run from the battery, via the starter, through the firewall to the ammeter and then back out the firewall to the alternator... You may want to check this yourself just to make sure I have that right...

I really have not thought about it much but this would explain what you see voltage on one side only.

I would check your firewall connections to make sure they are making good contact.. I would suspect that some of the other guys may have a simple test for the ammeter.. You could always buy an el-cheapo ammeter from the auto parts store and jumper it in to see if it works before you go too far with your original. If your original is NG look into the reproductions... In my 1963 I had all four of the original gauges "restored" for significant bucks... all worked for a short period of time and then died again.. All four are now GM reproductions... looks are spot on and what's even better, they work!

Good luck,

Joel

[Michael J.]

Re: Ammeter and washer pump issues

Thanks, I'll try to track that down.

[John H.]

Re: Ammeter and washer pump issues

Thanks, I'll try to track that down.

Michael -

You don't want to try an aftermarket ammeter, as your battery gauge isn't an ammeter - it's a sensitive voltmeter. The black/white wire at the battery gauge goes to the screw terminal buss on the horn relay, and the black wire goes to the battery cable stud on the starter solenoid - both should show battery voltage with the key off. The battery gauge simply displays the voltage difference between those two connections in terms of whether current is flowing TO or FROM the battery.

Since one of your two wires doesn't show power at the battery gauge, that circuit is open between the gauge and its source; both of those wires go through the inboard multiple bulkhead connector on the engine side of the fuse block, and those connectors are famous for corrosion; use a test light and find out where the power stops in that circuit.

[Michael J.]

Re: Ammeter and washer pump issues

Thanks John, that's great info. I shouldn't have called it an ammeter, since I know it just measures voltage. It is the black wire that has no volts, so I will track that down quickly. Just hope the voltmeter is working. It is tilted to the left, discharge, side now with voltage on only one side maybe that is a good sign? I do have a replacement gauge I got from Ecklers in case mine is gone. Thanks again for the precise knowledge!