Need some help on troubleshooting dash gauges

[Wietse]

Hey all,

Today i've removed and cleaned up the connectors on the fire wall.
I've found the black wire to the Amp meter badly corroded and the crimped socket broke off.
I measured resistance to confirm i cut the correct wire (near the ignition block) and already measured a lot of resistance across that small length of cable.
There was quite some damage from a melt down on the socket that happened in the past.
The wire was badly corroded, so i cut this bad section out and replaced it with a new wire.
All connectors were quite dirty so think it was well worth it.

Although now something new arrises: When driving the Amp meter is showing a charge nearly out of the scale when driving, during idle it sits around +10 - +20.
When switching the lights on the amp meter does react and shows a low charge.
Also the other gauges, fuel, coolant temp and oil pressure show a normal reading when idle but all drop to zero when driving or bringing up the rpm.

This only started after the clean up job on the electrical connectors.
The dash circuit board is new and also the voltage regulator on the board is a new one (solid state)

Checked and measured the voltage output of the alternator, which shows 14.4 during idle but exceeds 20 volt when revving wtf.
Does this mean the voltage regulator is wasted?
Guess the voltage regulator for the dash gauges just does his job and shuts down the power supply as the supply voltage is exceeding it's input limits.

 

[Speedbird]

Not a lot to go on.
Is this a two wire alternator?
Electronic voltage reg?
It need a good ground to regulate properly.
It also needs a good supply to accurately regulate.
What voltage is it seeing? It needs an accurate reference voltage.
On that black wire that's the alternator feed . On my driver,
I recently eliminated the Packard firewall and hard wired the amp feed wires and "run" wire which feeds lots of things including your regulator.
Best thing. And the headlight relay mod too.

 

[Wietse]

Hi,

It's a single wire alternator, regulator is original mechanical style.
I just opened it to have a look on it's condition, cleaned it up and soldered the wire ends on the pins to create a better contact as they are slightly corroded.

I will reinstall it and check again.
I will also check the input voltage as you mentioned, i did not check this previously.

 

[Wietse]

Just tested again and still the same, when revving up the voltage on the alternator goes above 20 volts.
On the battery is a good 14 volts.
The reference voltage on the regulator input is 12.8 - 13.6 volts, fluctuating all the time.

 

[gtxno1]

Get yourself an electronic regulator they have ones that look just like the original should take care of your voltage issues the gauges I would check your grounds and connections

 

[mmissile]

I ended up replacing my dash harness, engine harness, and some gauges. All is good. This 50 year-old ****, just doesn't get it.

 

[Yatzee]

Hey all,

Today i've removed and cleaned up the connectors on the fire wall.
I've found the black wire to the Amp meter badly corroded and the crimped socket broke off.
I measured resistance to confirm i cut the correct wire (near the ignition block) and already measured a lot of resistance across that small length of cable.
There was quite some damage from a melt down on the socket that happened in the past.
The wire was badly corroded, so i cut this bad section out and replaced it with a new wire.
All connectors were quite dirty so think it was well worth it.

Although now something new arrises: When driving the Amp meter is showing a charge nearly out of the scale when driving, during idle it sits around +10 - +20.
When switching the lights on the amp meter does react and shows a low charge.
Also the other gauges, fuel, coolant temp and oil pressure show a normal reading when idle but all drop to zero when driving or bringing up the rpm.

This only started after the clean up job on the electrical connectors.
The dash circuit board is new and also the voltage regulator on the board is a new one (solid state)

Checked and measured the voltage output of the alternator, which shows 14.4 during idle but exceeds 20 volt when revving wtf.
Does this mean the voltage regulator is wasted?
Guess the voltage regulator for the dash gauges just does his job and shuts down the power supply as the supply voltage is exceeding it's input limits.

The amp meter is showing the load downstream ( or internal)if that makes any sense to you. Somewhere beyond the amp meter ( or at the meter) is where your problem lies and I'd bet it's a poor connection or an intermitent connection. You need to verify this or the arcing from a poor connection can cause horrific results. Bypass the amp gauge temporarily and go direct to the fuse box lead-in. A volt gauge or meter is a better bet for voltage spikes and drops and the fuse box will protect against direct shorts. Should a fuse blow, at least you'll know the circuit that caused it.

 

[miller]

With all the corrosion mentioned, good chance the wiring itself could be in bad shape. If a wire gets corrosion inside the plastic covering, it's not flexible, like new wire.

 

[Wietse]

I get the point of downstream load (load beyond the amp meter, not at the alternator circuit)
Now realising that i had the dash out yesterday again, which includes disconnect and connect the wires on the amp meter. Could be a poor connection there indeed.
Btw, if i understand well, there is a power supply coming from the amp meter going to the fuse box right?
In the drawing it shows an arrow and says "accessory circuit breaker".
So to by-pass the amp meter i just connect both wires behind the amp meter right?

So most likely the bad connection(s) cause excessive load on the alternator which is putting out too much voltage?
This leading in the dash gauges stop working as they are protected by the solid state voltage regulator for the dash?

I was already planning to order a engine harness, upgraded voltage regulator and a new alternator as this one already has some wear on the bearings. (which can be noted when belt is removed)

Before this the gauges were working fine so i have no reason to believe that the gauges are at fault, specially as all of them go down together.

 

[Yatzee]

I get the point of downstream load (load beyond the amp meter, not at the alternator circuit)
Now realising that i had the dash out yesterday again, which includes disconnect and connect the wires on the amp meter. Could be a poor connection there indeed.
Btw, if i understand well, there is a power supply coming from the amp meter going to the fuse box right?
In the drawing it shows an arrow and says "accessory circuit breaker".
So to by-pass the amp meter i just connect both wires behind the amp meter right?

So most likely the bad connection(s) cause excessive load on the alternator which is putting out too much voltage?
This leading in the dash gauges stop working as they are protected by the solid state voltage regulator for the dash?

I was already planning to order a engine harness, upgraded voltage regulator and a new alternator as this one already has some wear on the bearings. (which can be noted when belt is removed)

Before this the gauges were working fine so i have no reason to believe that the gauges are at fault, specially as all of them go down together.

 

[Yatzee]

Simple things can appear as big problems when in reality they're not. Take a deep breath and think about just exactly what you did that could have created the issue. They worked before, right? Like any caring car guru you decided that the electrical needed attention, right? So if this is the case what did you do that changed things? One time I had to pull the glass fuse on my friends car to work on his heater. I promptly pushed the fuse back in place but the heater worked intermitently. I replaced the fuse but the problem still existed. With the fuse panel facing down from under the dash, little did I know that one end of the fuse holder retracted back into the plastic housing when I pushed the fuse into it the first time. Point is, walk away for a bit, regroup, and look/test everything again. It would be a financial shame to toss money away if the solution to the problem is really simple. Like many of us you may have just missed something simple.

 

[Wietse]

You are right, if you keep digging you get lost in the end.

Looking back, i've replaced all the dash components and since did not drive it really.
I did notice from since i own the car that there is always some fluid coming out of the battery vent.
Battery is fairly new, so makes me wonder that it has been like this all the time since i own the car.
Just never noticed because i was still with the old voltage regulator for the dash gauges which probably will not be so protective agains over voltage as this new solid state unit.

And because the bad connection on the 12 volt line towards the Amp gauge never noticed the insane over-charge that is happening.
Regardless i will order a new alternator and voltage regulator to have things reliable, in the mean time i will go through all connections and clean all up and make sure everything has good ground.
I read on another topic someone run a ground wire from the alternator to the regulator mounting bolt, is there a dedicated ground connection on the alternator for this or just hook it up on the mounting bolt?

Edit: With the engine running i've checked again the voltage on the flood line from alternator to the regulator and found that high, around 17 volt at idle and increasing when revving the engine up. (yesterday i measured on the output side)

 

[Wietse]

So i did some more checks and found that the power supply for the ignition is coming direct from the battery and goes through a relais.
Both "run" (blue cable) and "start" (brown cable) from the ignition switch are both connected and are used to operate the relais which after will supply power to the MSD coil.
With the "brown" start signal going through the ballast resistor for some reason.

I read on another topic that this high amps pull could be caused by a bad battery or bad voltage regulator.
To confirm this i've changed out the battery for another one which was fully charged and resulted in the same issue with a high voltage on both the "field" wire and the rest of the system. (17 volt at idle and beyond 20 volt when rpm is increased to approx. 1000-1200 rpm.)

Leaves me with a bad voltage regulator according me.

 

[luigi164]

Wietze,
I've had the same problems as you. As you've already said: bad voltage regulator..

Luigi

 

[Wietse]

Thx Luigi,

I ordered a new voltage regulator through Summit, hopefully will be here in a few days.
Hopefully this will sort this problem.

One more thing you might be able to help with as well as i've been asking around in other topics but no reactions so far.
Do i need a signal adapter if i want to make the tachometer operational with an MSD distributor (part 8387) and a MSD Blaster SS coil (part 8207).
I want to order a new tachometer from Classis Industries, my current tach did not work properly with this hooked up to the distributor's dedicated "grey-wire" tach signal wire.
Also tried the neg - side of the coil but same results.
This setup works without any ballast resistor and is directly fed from battery through a relay.
According me i will need the below adapter, as my system is non-current limited and originally was equipped with a ballast resistor, correct me if i am wrong.

 

[luigi164]

Hi,

Rockauto usually ships fast ( I've ordered several parts there too) but some parts are also available here in Holland. I bought my VR here at APS in Breda.
http://www.oldschoolproducts.nl/home has them too.

Unfortunally I don't know anything or have experiences with electronic ignition so I can't help you with that.
My Newport still runs with "old fashioned" points..