I soldered in a new line (black/blue) for the illumination of the speedo...the one I fried. I decided to check out the ground, and just for the hell of it put the resistance test to everything. The one illumination wire I repaired goes to zero when I touch the socket to a known ground, but the other illumination wire (another black.blue) shows infinite resistance.
What's that about?
Also, since the VDO aftermarket temp gauge was out, I did the same to it:
The red, green (light that is spliced into one of the black/blue wires from the tach), and one of the blacks all go to zero. The other black goes to about 1200 ohms.
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Full Version: OK...Before I Button Her Back Up...(elec. glitches saga)
QUOTE(kenshapiro2002 @ Oct 2 2009, 01:25 PM) 
Also, since the VDO aftermarket temp gauge was out, I did the same to it:
The red, green (light that is spliced into one of the black/blue wires from the tach), and one of the blacks all go to zero. The other black goes to about 1200 ohms.
I'm assuming you know that the "G" on VDO gauges stands for "Geber" which means "Sending Unit" and not ground ...
Andy
When you measured the resistance of the repaired illumination wire, what did you measure it to? To ground? To the other illumination lamp?
The two illumination wires for the speedo lights should be connected together and a resistance measurement from one light wire to the other should be zero ohms.
Each illumination wire to ground should read the same value.
The two illumination wires for the speedo lights should be connected together and a resistance measurement from one light wire to the other should be zero ohms.
Each illumination wire to ground should read the same value.
What are you...nuts...asuming I'd know that? 
There are two black wires so I have no idea which one is supposed to go where. I think I know where they were hooked up before. I assume the red one is supposed to go to the positive terminal, one of the blacks to "G" and the other to ground.
Also, since the VDO aftermarket temp gauge was out, I did the same to it:
The red, green (light that is spliced into one of the black/blue wires from the tach), and one of the blacks all go to zero. The other black goes to about 1200 ohms.
I'm assuming you know that the "G" on VDO gauges stands for "Geber" which means "Sending Unit" and not ground ...
Andy
There are two black wires so I have no idea which one is supposed to go where. I think I know where they were hooked up before. I assume the red one is supposed to go to the positive terminal, one of the blacks to "G" and the other to ground.QUOTE(SirAndy @ Oct 2 2009, 07:12 PM)
QUOTE(kenshapiro2002 @ Oct 2 2009, 01:25 PM)
Also, since the VDO aftermarket temp gauge was out, I did the same to it:
The red, green (light that is spliced into one of the black/blue wires from the tach), and one of the blacks all go to zero. The other black goes to about 1200 ohms.
I'm assuming you know that the "G" on VDO gauges stands for "Geber" which means "Sending Unit" and not ground ...
Andy
I was measuring the outside of the socket, with bulb installed to a ground. Just now I went out and did as you suggested...tested the to each other. It measured zero. Measuring either one, on the inside of the socket to ground also showed zero. It I went to the outside with bulbs installed, it depended on whether the bulb was twisted "just right". If I did adjust them they also went to zero when touched to a known ground.
When you measured the resistance of the repaired illumination wire, what did you measure it to? To ground? To the other illumination lamp?
The two illumination wires for the speedo lights should be connected together and a resistance measurement from one light wire to the other should be zero ohms.
Each illumination wire to ground should read the same value.
QUOTE(Spoke @ Oct 2 2009, 07:16 PM)
When you measured the resistance of the repaired illumination wire, what did you measure it to? To ground? To the other illumination lamp?
The two illumination wires for the speedo lights should be connected together and a resistance measurement from one light wire to the other should be zero ohms.
Each illumination wire to ground should read the same value.
Just to clarify, this is what you measured:
socket center to socket center = 0 ohms: This is ok.
socket center to socket outside = 0 ohms: I would think this would show some resistance. The resistance should be the other bulbs in the circuit.
Did you use new ir different socket or the first one that fried itself?
socket center to socket center = 0 ohms: This is ok.
socket center to socket outside = 0 ohms: I would think this would show some resistance. The resistance should be the other bulbs in the circuit.
Did you use new ir different socket or the first one that fried itself?
Yes...center socket to center socket was zero.
Never did center to outside. I did outside of each socket (one at a time) to a known ground (the screw on the driver side door hinge is a very good ground on my car).
I was measuring the new socket as well as the other one that I didn't fry.
Just to clarify, this is what you measured:
socket center to socket center = 0 ohms: This is ok.
socket center to socket outside = 0 ohms: I would think this would show some resistance. The resistance should be the other bulbs in the circuit.
Did you use new ir different socket or the first one that fried itself?
Never did center to outside. I did outside of each socket (one at a time) to a known ground (the screw on the driver side door hinge is a very good ground on my car).
I was measuring the new socket as well as the other one that I didn't fry.
QUOTE(Spoke @ Oct 2 2009, 09:38 PM)
Just to clarify, this is what you measured:
socket center to socket center = 0 ohms: This is ok.
socket center to socket outside = 0 ohms: I would think this would show some resistance. The resistance should be the other bulbs in the circuit.
Did you use new ir different socket or the first one that fried itself?
Socket center to ground is very important as the short circuit that caused the car-b-q of the wire did just this or close to it. Measure from socket center to socket outside and socket center to ground. The socket center to socket outside w/o the bulb in place should be infinite and the socket center to ground should be greater than 10 ohms or so as it will measure all the existing lamp filaments to ground.
Both Speedo illumination sockets show:
Center socket to outside is infinite.
Center socket to ground is 4-5 ohms.
Outside socket to ground with bulb in place is 20-30 ohms.
Socket center to ground is very important as the short circuit that caused the car-b-q of the wire did just this or close to it. Measure from socket center to socket outside and socket center to ground. The socket center to socket outside w/o the bulb in place should be infinite and the socket center to ground should be greater than 10 ohms or so as it will measure all the existing lamp filaments to ground.
Center socket to outside is infinite.
Center socket to ground is 4-5 ohms.
Outside socket to ground with bulb in place is 20-30 ohms.
QUOTE(Spoke @ Oct 3 2009, 08:13 AM)
Socket center to ground is very important as the short circuit that caused the car-b-q of the wire did just this or close to it. Measure from socket center to socket outside and socket center to ground. The socket center to socket outside w/o the bulb in place should be infinite and the socket center to ground should be greater than 10 ohms or so as it will measure all the existing lamp filaments to ground.
Well, everything is back in place...no smoke, no sparks, no "squawking" relay...everything is perfect except my VDO after market temp gauge isn't operating. Guess I'll try reversing the two black wires since those are the only two I might have reversed. Much relief. I really appreciate all the help. Instead of throwing hundreds at some local wrench, I did it with your help, learned along the way, feel closer to the green beast and saved some bucks to put into making her even better.
QUOTE(kenshapiro2002 @ Oct 6 2009, 01:33 AM)
Well, everything is back in place...no smoke, no sparks, no "squawking" relay...everything is perfect except my VDO after market temp gauge isn't operating. Guess I'll try reversing the two black wires since those are the only two I might have reversed. Much relief. I really appreciate all the help. Instead of throwing hundreds at some local wrench, I did it with your help, learned along the way, feel closer to the green beast and saved some bucks to put into making her even better.
Has the temp gauge ever worked?? (Did you have a look at the bottom of the engine to see if the taco plate and sender exist?)
It was working perfectly until I rebuilt the speedometer and started playing around behind the dash.
Well, everything is back in place...no smoke, no sparks, no "squawking" relay...everything is perfect except my VDO after market temp gauge isn't operating. Guess I'll try reversing the two black wires since those are the only two I might have reversed. Much relief. I really appreciate all the help. Instead of throwing hundreds at some local wrench, I did it with your help, learned along the way, feel closer to the green beast and saved some bucks to put into making her even better.
Has the temp gauge ever worked?? (Did you have a look at the bottom of the engine to see if the taco plate and sender exist?)
QUOTE(Rod @ Oct 6 2009, 04:24 AM)
QUOTE(kenshapiro2002 @ Oct 6 2009, 01:33 AM)
Well, everything is back in place...no smoke, no sparks, no "squawking" relay...everything is perfect except my VDO after market temp gauge isn't operating. Guess I'll try reversing the two black wires since those are the only two I might have reversed. Much relief. I really appreciate all the help. Instead of throwing hundreds at some local wrench, I did it with your help, learned along the way, feel closer to the green beast and saved some bucks to put into making her even better.
Has the temp gauge ever worked?? (Did you have a look at the bottom of the engine to see if the taco plate and sender exist?)
Do you know what the sender is for your temp gauge? A "taco" plate sender might not be the correct sender for a VDO aftermarket gauge but that's not the issue here since it was working and now is not. The taco sender only applies to accuracy of the temp. There is a VDO sender that replaces the oil drain plug; that's all I recall this early in the morning (which makes me wonder, why aren't people at work?). Anyway, a taco sender would have been added by a PO for a 70 model. You can access VDO installation instructions to verify your wiring. One place that comes to mind (again, it's early) is eGauges (like: egauges.com)
I'm not at work because I retired two years ago at age 54...best job I ever had.
Do you know what the sender is for your temp gauge? A "taco" plate sender might not be the correct sender for a VDO aftermarket gauge but that's not the issue here since it was working and now is not. The taco sender only applies to accuracy of the temp. There is a VDO sender that replaces the oil drain plug; that's all I recall this early in the morning (which makes me wonder, why aren't people at work?). Anyway, a taco sender would have been added by a PO for a 70 model. You can access VDO installation instructions to verify your wiring. One place that comes to mind (again, it's early) is eGauges (like: egauges.com)
QUOTE(type47 @ Oct 6 2009, 09:22 AM)
Do you know what the sender is for your temp gauge? A "taco" plate sender might not be the correct sender for a VDO aftermarket gauge but that's not the issue here since it was working and now is not. The taco sender only applies to accuracy of the temp. There is a VDO sender that replaces the oil drain plug; that's all I recall this early in the morning (which makes me wonder, why aren't people at work?). Anyway, a taco sender would have been added by a PO for a 70 model. You can access VDO installation instructions to verify your wiring. One place that comes to mind (again, it's early) is eGauges (like: egauges.com)
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