Amp Gauge wiring 88-89 CMC

Good discussion-

TheSamba.com :: Beetle - 1958-1967 - View topic - VDO amp meter wiring?

Thanks Wolfgang! Reading that post is helpful....I need to get a look at the wiring at the Solenoid and see what (if anything) orange wire hopefully, is connected there.  Further study of the manual wiring diagram might help me determine if the orange wire(s) that have been cut with nothing connected under the dash around the steering wheel column were intended to be connected to the Amp Gauge or something else..

To Forum members...I have spoken with a local Auto Electric guy and he recommends that I purchase a Volt Gauge from VDO to match the remainder of the new updated gauges in the dash. His reasoning is around safety. His experience around Ampere Gauges causing fires is behind his recommendation and says a matching VDO Volt Gauge would accomplish what I want a Gauge to do.

I LIKE your guy!  

He's exactly right.  Typical ammeters had a big, honkin' 10 ga. wire coming right from the battery with, at most, a 60 amp fuse-able link in series, through the ammeter and on to feed the fuse block.  Touch anything grounded to that circuit anywhere along the way and sparks were the least of your problem.  I come from the school bus world and they disappeared from those back in the 1970's.

Manufacturers went to volt-meters decades ago just for that reason:  The Voltmeter could be tied in to the ignition circuit (so it goes off when the key is switched off) and it just samples the general battery/charge voltage, rather than carrying all of the current needed to run the car through it.  While it tells you different info than an ammeter, it is just as useful, maybe more.  Now all you have to do is find a voltmeter with the same face as your other gauges to match.

Gordon, thanks for adding your comments...I am going to make the move to a Volt Gauge. My gauges are the VDO Royale series and I am going to order it within minutes....It is from the same series....I'll attach a photo of it....

Yep, ammeters are trouble. Unfused power from the battery routing through the dashboard to the generator/alternator. Who thought this was a good idea? A good voltmeter will tell you a lot more about the condition of the battery and charging system anyhow. When you first turn the ignition on it should read 12 volts or a little over, depending on how long it's been sitting. When you crank the engine it shouldn't fall below 10 volts. If it does, it an indicates of a weak battery.

Once the engine is running at road speed the voltmeter should hover around 14 volts, indicating the alternator/generator is charging the battery. It may dip close to 12 at idle, especially generator systems. Turning the headlights on at road speed should have little impact on an alternator system, while a generator will see a bit more drop. At ide with the lights on, expect both to sag towards 12, a generator more so than an alternator. As long as it bounces close to 14 volts at road speed, you can rest assured the system is charging the battery.

Thanks Eric for your reply....Now I know what to expect with voltage increases and decreases with starting, idling, running, etc. You mentioned 10 volts and weak battery ....I am going to check for any parasidic draw and the value of this thread now leads me to question the cutting of this orange wire left under the dash prior to my ownership and the possible dangerous live wire that is unfused. I must get to the bottom of this. All replies have been helpful.

Parasidic draw observations...After investigating the reason for my Ammeter not working in the process of fixing my charging system, I measured the voltage of my battery on four consecutive days starting with 12.75 volts DC. Each day my battery showed .01 fewer volts and is now at 12.71 volts. When the key is not turned to "on" or "accessory", I am not aware of anything on or likely to drain the battery.  Although I have an Deltran Battery Tender to keep the battery charged and I know I could install a Battery Disconnect device, I wondered what, if any draw is acceptable or expected? If the answer is "no draw" is acceptable or expected" then I will know that I need to chase this Parasidic Draw down. I will start removing fuses for all circuits that are "fused" and identify any circuits that are "unfused" like that orange wire I found cut under the dash and need to trace back to the origin which may still be connected at the solenoid.

Thanks...Mike

Some battery devices charge the battery then put a load on the battery to draw it down some, and then they charge it back up. These devices are generally considered better than a tender that just keeps a trickle charge on the battery all the time.

Thanks Robert! This information is helpful...I neglected to be clear re the battery Tender. I haven't had the battery Tender connected while testing the battery voltage decline. Prior to driving the car on Saturday I charged the battery to full, drove two miles, returned home and without battery Tender on Monday I started measuring for parasidic draw....Mike

Do you have a radio in the car?

Umm, it is absolutely normal for a lead-acid battery to lose a small amount of charge per day. I don't think 0.01 v is a lot at all. If it was 0.1 volts, that might be a worry.

That is not parasitic draw doing that, it is natural sulfation of the plates of a typical lead acid battery.

Lead-acid, nickel-cadmium, and Nickel-metal-Hydride batteries all decay charge levels over time. I think the only exception are Lithium type batteries, possibly others.

@Robert M posted:

Some battery devices charge the battery then put a load on the battery to draw it down some, and then they charge it back up. These devices are generally considered better than a tender that just keeps a trickle charge on the battery all the time.

Deltran brand Battery Tenders charge until the battery reaches 12.5V then shut off until they drop to ~11.9V.  Until they stop working right that is. Lots of people confused battery tenders with trickle chargers.

DannyP & dlear1476, these explanations also increase my understanding of the electrical system, charging and what the Deltran Battery Tender will be doing.

The VDO Royale Cockpit Volt Gauge that matches the remainder of my replacement gauges is scarce as hen's teeth to find but I found stock in the U.K. and it was shipped yesterday...

Thanks to all who have contributed...I really appreciate it..

Mike

Gordon, I do have one of those Bluetooth audio streaming and FM Radios from Woody's Custom Shop but the power is switched when the key is turned on. Based on that I didn't think it could draw but I haven't pulled the fuse.

It may draw a small amount of current to keep the presets alive in memory.  

Usually those newer radios have a switched, wake-up mode from the key as well as a "keep everything alive" mode running in the background.

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Mike, I agree with Danny.

The fact that the voltage dropped only .04 over four days is pretty good evidence that there is NO parasitic draw. And 12.75V is pretty typical for a healthy lead acid.

Unlike modern cars, ours have such simple electrics that almost nothing in the car would normally draw the battery down over time. That's why Gordon asked if you have a radio. The memory circuit or clock in a radio is one thing that might. An alarm is another.

If the car gets a good drive (maybe an hour or so) about every two weeks, the battery should stay up if the charging system is healthy.

If it regularly sits for longer than that (especially in winter weather), you might want to consider one of the new generation of 'smart' chargers. These are pretty sophisticated, with software that monitors and tests a battery continually, turning on charging cycles as needed that are designed to maintain a battery, without overdoing it.

I use a CTEK over the winter, if the car's not getting out much. These are a little pricey compared to the most basic ones, but set it up and forget it.

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@Sacto Mitch posted:

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I use a CTEK over the winter, if the car's not getting out much. These are a little pricey compared to the most basic ones, but set it up and forget it.

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There is a reason you get a CTEK with every Ferrari purchase; they're just that good.

Thank you everyone! This entire discussion for me has really helped me take my car to the next level where electrical safety and reliability is essential. After rebuilding the car for a few years, this summer I have been driving it locally on short drives to build confidence in the car.  My focus now is testing the reliability Of it on longer fun runs with others.....a giant step forward!!..Mike

Summer heat is every bit as bad for batteries as winter cold. If you get a good week of 90 plus temps and your car is in a shed(or trailer like mine sometimes) the battery WILL go flat.

I use the tenders any time of year whenever I let the cars sit for a week or two.

Mike, that's how you do it. Slowly increase your distance and confidence in the car!