Disabling 1966 B Body Ammeter

4SPEED427 · A Poncho Legend!

Disabling 1966 B Body Ammeter

Canadian Poncho · A Poncho Legend!

Neat gizmo Carl. I see them on Amazon but they are more expensive. I guess the only benefit of getting one on Amazon is you'd have it in a couple of days
www.amazon.ca/XCSOURCE-Charger-Voltmeter-Thermometer-Temperature/dp/B01MAVPKCY/ref=sr_1_3

MC · Canadian Poncho Superstar!

I haven't heard of this issue for GM cars, but I have for Mopars. My understanding is that it's typically due to a bad connection at the bulkhead connector (at the firewall) caused by corrosion or otherwise. I've seen people rewire and install a voltmeter in place of the ammeter, but I've also heard that you can alleviate the situation (on Mopars) but simply taking apart the bulkhead connector and checking/cleaning the contacts, then greasing and reinstalling.

Where does the issue occur on Pontiacs? I'd like to know in the event that I actually get one of these some day...

68 Grande · Guru

Looks like an economical method to monitor your charging system. Carl, when you disabled your ammeter, where exactly did you remove the wires?

cdnpont · Canadian Poncho Superstar!

It's a very good idea Carl, and the USB is very useful. The one negative I see is that glowing red display. I'd not want it in my face all the time. I suppose you could apply a little strip of dark window tint across it? Or just use it as required.

Like Todd linked, there are many good choices on Amazon.ca/Prime. And some well priced with a get to your door next day.

https://www.amazon.ca/s/ref=nb_sb_noss?url=search-alias%3Dautomotive&field-keywords=automotive+cigarette+lighter+voltage+meter&rh=n%3A6948389011%2Ck%3Aautomotive+cigarette+lighter+voltage+meter&ajr=0

4SPEED427 · A Poncho Legend!

68 Grande wrote:

So far I unhooked the wire from one side which goes to the big red wire at the horn relay. I plan to unhook the other side which goes to the cable at the starter the next time I work on the car. I had someone tell me that my charging system won't work if I don't put a jumper wire across the connector that is on the back of the ammeter. I haven't looked at the wring diagram yet to see if I can figure out if that is true. I will likely just try it unplugged and see if it charges. If not I'll have to put a jumper wire in the connector and try it that way. Either way, I will have eliminated the source of fires.

4SPEED427 · A Poncho Legend!

cdnpont wrote:

The one negative I see is that glowing red display. I'd not want it in my face all the time.

I drive it so little in the dark I don't think it will be an issue but if I do find it too bright I'll just unplug it for that time.

MC · Canadian Poncho Superstar!

Would you be able to achieve the same degree of safety if you put a fusible link in line with the ammeter? Then you could have the best of both worlds...

DANO65 · Poncho Master!

Thanks for posting that Carl. I was the one asking about it. Would work great in my camper to keep an eye on the battery levels when we are not plugged in. I kinda like the one Todd linked, as it shows temperature and voltage at the same time. Food for thought for spring time.

68 Grande · Guru

Carl Stevenson wrote:
So far I unhooked the wire from one side which goes to the big red wire at the horn relay. I plan to unhook the other side which goes to the cable at the starter the next time I work on the car. I had someone tell me that my charging system won't work if I don't put a jumper wire across the connector that is on the back of the ammeter. I haven't looked at the wring diagram yet to see if I can figure out if that is true. I will likely just try it unplugged and see if it charges. If not I'll have to put a jumper wire in the connector and try it that way. Either way, I will have eliminated the source of fires.

My car has been converted to an alternator at some point and on recollection, I have two wires that join into one near the firewall and then that wire I believe goes to my ammeter (which is now a volt meter I guess). The single wire goes into the firewall and I have not traced it to see where it actually goes but I believe it goes to the meter.

Anyways, once I accidently separated the two wires as the wires have a nice plug and I somehow leaned on it and separated the wires. Of course the ammeter (voltmeter) did not work but I noticed that my battery was almost dead as I had my lights on, so they were drawing current out. I plugged the wires back in and the meter worked and showed the system charging but I strongly thought at the time that my system ceased to charge when the wires were separated, but I could not prove my theory and I didn't think much more about it. Funny, but I also had this suspicion of the system not charging when the meter was disconnected.

So, I ordered one of these cheap 4 in one plug in volt meters yesterday, for that price, I can wait 6 weeks.

4SPEED427 · A Poncho Legend!

DANO65 wrote:

Thanks for posting that Carl. I was the one asking about it. Would work great in my camper to keep an eye on the battery levels when we are not plugged in. I kinda like the one Todd linked, as it shows temperature and voltage at the same time. Food for thought for spring time.

This one rotates, a few seconds for volts, then a few for temp, then a few for amps. But yes, the idea of both at the same time is kind of cool too.

a421cat · Guru

I know this is the wrong year but on my 61 the ammeter failed and the car would not start. I pulled the plug off the back of the ammeter and added a jumper. Car now runs but no amp meter. I will order one of these units and monitor my generator via the cigarette lighter socket. Great idea.

Bill.

4SPEED427 · A Poncho Legend!

Hmm, I wonder what that wire powered on the 61 that made it not start?

I'll have to trace the wire on my wiring diagram again. I haven't tried starting my car yet. All I've done so far is unhook the wire at the horn relay. I plan to unhook the other end at the starter when I pull the 283 out.

Fake68 · Guru

In this case, I think the car most likely did not start because the underhood harness power feed from the battery was compromised (broken, burnt link etc). Jumping the ammeter wire creates an alternate source to power up the underhood harness (from the opposite ammeter connection, usually the starter). Everything is now pulling power across the ammeter wiring.

4SPEED427 · A Poncho Legend!

I may try mine this afternoon to see if it starts. I finished wiring my lighter socket up so a fused ignition source this morning so that this plug in charger/voltmeter will only work with the key on now. I won't have to worry about forgetting it in the socket and having the volt meter kill my battery.

I still have the power wire from the starter to the ammeter hooked up to the back of the ammeter, but the wire from there to the horn relay is unhooked, so I'm sure the ammeter won't work. However, if that wire is tapped into along the way to power up another harness, that will likely still work. If I leave it hooked to the starter I will put a fusible link in where it comes off the starter. I also plan to put a fusible link into the red wire that comes off the positive battery post and runs across the rad cradle to the horn relay. That is a live power wire with no protection, I can't believe they did that.

Fake68 · Guru

The small harness feed wire (factory molded into the + battery terminal) should be a fusible link. It runs to a little isolator block on the backside of the rad cradle where the engine side harness joins. That's the protection. You know... that little wire you always see on old cars replaced with a fresh red lead and a crimp on terminal ??

4SPEED427 · A Poncho Legend!

As far as I've ever seen on 66 B bodies, they don't have it. I know the one you mean but I've seen some very original cars and it's not there. You could be right, and sure SHOULD be right. An unprotected hot wire seems foolish.

I started my car in the garage for a few seconds. It started fine and instantly went to 16.2 volts, which of course is way too high but I shut it off immediately. I imagine the regulator would have kicked in very shortly.

Fake68 · Guru

The original black ones look like a regular wire. Not like the spongy insulation ones.

MC · Canadian Poncho Superstar!

So is there no way to keep a functional ammeter in an old car? I mean, as long as you freshen up the wiring and keep the connections good, shouldn't it be fine? I don't recall cars going up in smoke every day back in the old days... seems like a carburetor fire would be the more likely culprit to burn one's old car to the ground.

I like ammeters because they give you a real time picture on how your charging system is working.

hawkeye5766 · Canadian Poncho Superstar!

MC wrote:
So is there no way to keep a functional ammeter in an old car? I mean, as long as you freshen up the wiring and keep the connections good, shouldn't it be fine? I don't recall cars going up in smoke every day back in the old days... seems like a carburetor fire would be the more likely culprit to burn one's old car to the ground.
I like ammeters because they give you a real time picture on how your charging system is working.

Could always put in a circuit breaker(hidden)..will just kick out if too much draw(short).

hawkeye5766 · Canadian Poncho Superstar!

To me, ammeters are good in a car especially if wanting to stay original but voltmeters are better. Can always run both. In my car I only have a Volt meter that is hidden in the ashtray. This way I can have the ashtray open while cranking/cruising and close so unseen at shows. The other plus with a volt meter when hooked up to hot on crank/run...is that you can see your voltage drop while cranking. If your down to 9.5 volts on crank,you know your bat is down or starter is drawing too much. Just get a bit more info running a volt meter.

(Bat charger on)

MC · Canadian Poncho Superstar!

Can't argue with your points, but for me an ammeter spells out what your charging system is doing more clearly. You can see when your system is discharging, when it is charging, and when it is sitting idle. Maybe it's all the same, but I like to see instantaneously what is happening with the system, like it is continually calling for a light charge when it should be charged already, or it has suddenly started to discharge, without having to watch for digits to change. Seems to me a voltmeter would have a bit of a lag on it waiting for the battery charge to change, but I could be wrong here? Maybe I'm just too old school.

4SPEED427 · A Poncho Legend!

My experience with voltmeters at our off grid cabin has been that the meter responds instantly to change, so I am hoping this is true with alternators and solar panels! When the sun goes behind a cloud there the voltage drops instantly, or when the charge controller cuts off the charging, we see it instantly.

hawkeye5766 · Canadian Poncho Superstar!

MC wrote:
Can't argue with your points, but for me an ammeter spells out what your charging system is doing more clearly. You can see when your system is discharging, when it is charging, and when it is sitting idle. Maybe it's all the same, but I like to see instantaneously what is happening with the system, like it is continually calling for a light charge when it should be charged already, or it has suddenly started to discharge, without having to watch for digits to change. Seems to me a voltmeter would have a bit of a lag on it waiting for the battery charge to change, but I could be wrong here? Maybe I'm just too old school.

They kinda work both in the same way(hard for me to explain). With a volt meter..if your amperage draw increases your voltage will decrease,but if above 12.6v you know it's doing it's job..With an ammeter..your amps will increase telling you it's charging. Best way to explain is the garden hose. Pull the spray nozzel and pressure drops but flow increases...the more the flow the lower the pressure. Current works in the same way...no load the higher the voltage and less amperage...load less voltage but more amperage flow. Don't think I'll ever be able to write a book.....can't get it from brain to finger!!

MC · Canadian Poncho Superstar!

Thanks for the responses guys. I'm familiar with basic circuit principles, including potential difference vs current flow (V=IR and all that). I haven't owned a car with an ammeter in years (Mopars... sorry guys), but my memory is that the needle seemed to react to everything the car was doing - it seemed way more sensitive than voltmeters (to me), so my impression was that it was a really precise way to watch what your charging system was doing. Voltmeters seemed (to me) to mostly show state of the battery, but didn't seem to be as sensitive as ammeters. Maybe it's because the cars I've had with voltmeters had smaller gauges with less graduation on the sweep, though. So, I guess that's how I developed my preference - maybe it's not grounded (pardon the pun) in fact, but purely by my interaction with the particular vehicles I've owned - so... a preference really. I also developed a liking for a voltage regulator that was mounted on the firewall vs contained within the alternator, and developed a dislike for ballast resistors, but that's another story.

My main question, actually, is whether it was entirely necessary to remove the ammeter from the circuit, and if that actually accomplishes anything. I've never had it happen to me, but I've read in the Mopar world that if the contacts at the main block connector through the dash become corroded you can have a meltdown at the connector due to the increased resistance and thus an electrical fire (the idea being that the ammeter flows the greatest current through that connector and is thus the problematic piece). I've been told all is good if you clean the contacts and apply some appropriate conductive grease before you put it back together to protect from future corrosion. Of course, if your wiring is in bad shape, with degraded insulation or suspect repairs by a previous owner, it should be replaced. I'm not sure what the problem is in old Pontiacs, mostly due to my lack of experience with them, but I would think if the wiring is in good shape, the ammeter shouldn't be a worry... but as I said I'm not intimately familiar with the cars.

From past experience, it seems that any faulty wiring can result in a short that feeds large amounts of current into circuits that were designed for lesser current flow (if a fuse doesn't catch it, or if a previous owner put a higher rated fuse in the panel because they got tired of replacing the proper one and didn't want to fix the problem), so is taking the ammeter out really protecting you from a problem?

To get right to the point (after all that), it's just a question as to what is the root cause of the issue that is making people want to disconnect their ammeters (and not my preference for one type of gauge vs the other). Really, my reason for the question is that if I end up with an old Canadian Pontiac, I want to know what I have to do to keep the ammeter. I also have a thing about having a nice dash with a dead gauge in it, so really I would have two reasons for not wanting to disconnect it. I've seen Mopars with an aftermarket voltage gauge installed in the place of the original ammeter, and I personally hated the look - it just cheapened the dash IMHO. But then I also have a thing about those aftermarket gauges mounted down by your knee where you can never see them and only really serve to whack your shin on it from time to time... so maybe I'm a little fussy when it comes to gauges... lol