'67 Amp Gauge Question...

[Patrick T.]

I've been busy the last few days getting my L-79 fired up after not running it for a year and half due to an engine bay restoration. The good news is the engine starts right up, runs good and everything works...except the amp gauge.

I have a complete new Lectric Limited engine bay wiring harness, which plugs into the firewall. Everything under the dash is undisturbed and worked OK the last time I drove car. Even with a new battery no matter if I have the engine running or not, the amp gauge needle stays on Zero, it won't move to the (+) side or the (-)side. I can't tell whether the battery is charging or not. When I put a heavy electrical load on the system like the lighter and blower motor, the needle doesn't move. I have power windows, which are disconnected. The harness is connected up to the horn relay; the headlights and motors are not connected yet, but the horn works.

I've double checked all the connections and they appear OK. All the cluster gauges work except this one. It worked fine before, and I can't figure why the needle won't move, either on way or the other. I was thinking of hooking up a couple small wire jumper clips to the gauge and to my battery charger on a 2 or 10 amp charge to see if the needle will move, so I can eliminate the guage from the equation. The gauge has not been removed from the dash or touched since I last drove the car. No fuses are blown.

Anyone have any idea why the needle is not moving? Any leads would be appreciated. Thanks, Patrick

[Wayne W.]

Re: '67 Amp Gauge Question...

I would advise against hooking up the charger to the terminals of the guage. A 1.5 volt battery will do, and then just scratch the leads to it. Dont hold it there. Are you sure that you have the lead that goes to the starter solinoid attached?

[Patrick T.]

Re: '67 Amp Gauge Question...

Wayne, I hooked the solenoid wires up using the '67 AIM as a reference. If you view the solenoid from the front, the large stud in the middle is for the battery cable, and an orange wire and a brown wire with large closed loop connections, which is sized for the same center stud as the battery cable.

To the left of the large middle post is a smaller post which a pink wire is attached. The small post to the right of the large stud gets one purple wire. That's all the wires in the harness, and they appear to be hooked up correctly, but I can double check and maybe scratch the leads up to make sure there is a good connection, but I'll have to take off the solenoid heat shield off to get to it tomorrow. Thanks

[Wayne W.]

Re: '67 Amp Gauge Question...

That sounds correct. The orange wire is the one that goes to the guage but it changes to black. The other wire to the guage is a Bk/W changed to OR at the horn relay.

[Gary Cederman]

Re: '67 Amp Gauge Question...

Patrick,

If you really believe that the only difference is the new harness then I would not bother with checking the meter with another supply at this time. The way the meter works is that it measures the voltage drop across a wire. This wire is called a meter shunt because it appears to short out (or shunt) the meter. The meter connects to the 'wire' on one side at the horn connection which is an 18 gage red wire. The other side of the meter is an 18 gage black wire that connects to the B post of the solenoid. If you look at the wiring diagram you will see that the horn connection and the solenoid connection are also connected together with a 12 gage red wire. Hence, shunting out the meter. The meter is measuring the voltage drop across a .1 ohm resistor (the wire).

You may want to disconnect the plug at the firewall and measure for continuity from each of these locations to the plug. (Of course, the battery is completely disconnected at this time.) Whatever the cause is, it is not allowing the voltage potential at the horn and the voltage potential at the solenoid to be observed by the meter. Being that this harness is from Lectric Limitied, I would be suprised that it is incorrect so, you may just have it connected wrong. Sorry, I don't think that I may be helping you much.

Let us know how it goes.

Good Luck,

Gary

[Gary Cederman]

Re: '67 Amp Gauge Question...

Patrick,

Sorry, but the colors that I stated were for a '63. I didn't think that it would be different. The theory is the same though.

Gary

[Patrick T.]

Re: '67 Amp Gauge Question...

Thanks guys, this one really had me stumped, but I finally got it working. I pulled the (two) plug-in connections at the firewall and cleaned up the prongs on the old dash harness again with sandpaper. Plugged them in again, making sure all those prongs were lined up correctly. Started up the car, and now the amp gauge works! It's the little stuff that gets you everytime.

Whatever was wrong with it, is apparently fixed now, thanks for your help. Patrick