Amp and Oil pressure gauge setup (1 Viewer)

[MrClean]

Hello everyone,

I'm working on getting my amp and oil pressure gauges working and need some assistance as I'm electrically challenged. These are the gauges that reside above the shifters on my '79. I'm thinkin that they are just not hooked up. The idiot lights on the main dash panel work, so I know I'm getting information from the senders. They do illuminate when I turn the lights on, but neither gauge registers any activity. I found some good diagram information from a post from gnob (see below). To start with, my question is where do the wires from the gauges terminate and how can I test the connections? Thanks.

 

[toy_tek]

Is this diagram also from a 79?

The fact that your idiot lights illuminate doesn’t mean you’re getting “info from the Senders”, there is an oil pressure switch (for the idiot light) and a pressure sender (for the gauge). Similar for the ammeter & charge light. Which is to say - the gauges get their info from different places than the idiot lights.

I’d start w checking the two fuses for the ammeter as indicated in the diagram.

For the oil pressure - is the sender connected? It should be forward passenger side of the engine, looking for the yellow/red wire. Be sure you have 12v at pin 26 (power from the gauges). You can also check continuity from the 4 way plug pin 28 to ground for the yellow/red wire.

Hope this helps

 

[MrClean]

Update...

Thanks toy_tek for your response. It helped alot. I understand the wiring diagram now. I found the oil sender (see pic) and there is a stub of a yellow/red wire on it. I also found the yellow/red wire (see pic) that was cut from the harness and was able to confirm continuity from the cut yellow/red wire all the way back to the yellow/red wire at the gauge cluster. And, I have 12V (well actually 10V) on the red/blue wire at the gauge cluster. I'm going to try and see if I can reattach the yellow/red wire to the existing sender or get a new sender.

Just to confirm, I can simply unscrew the oil sender from the engine block? Will I loose oil while it is removed?

 

[gnob]

it may drip a little, but all your oil wont fall out.

 

[ferg]

The sender is covered with a rubber cap. That's where you see the wire peeking out from. Just peel off the cover, no need to remove sender. Splice wire, have fun.

 

[jgranthevagrant]

Be careful if you do try to unscrew the sender. Use lots of penetrating fluid and let it soak overnight. The sender can break off flush if it has been sitting for a while or if there is rust built up. I broke one off once, and it was a pain to drill out.