New Alternator and flickering lights

[NorCalDiesel]

Last week I noticed a whining noise that has the same frequency as the alternator gauge. Meaning the gauge was rocking back and forth with the whining noise. The lights were also flickering and very dim. So I replaced the alternator and I now have great lighting, but they still flicker if I am not idling. If I am idling they are steady. Once accelerating t.hey flicker away.

I double checked the wiring and it is correctly hooked up. No more whining noise and the alt gauge shows it is charging the battery. Starts right up and the lights are much brighter. Could the voltage regulator be the problem?

BTW, we don't drive this scout much at night so the flickering lights could have been going on for a while without notice..

Thanks
Pat

'70 Scout 800A

[Thomas]

---Many might not know, some will, but the headlight switch has an internal circuit breaker. When there is a minor short, the headlights will flicker, as a result, letting the driver know there is a problem rather than simply blowing the fuse while careening down the road at 50+ mph.

---The headlights are ground at the dash, on the speaker mounting stud. Teh ground is often interrupted by the rusted/rotted/cancered connection between the battery and the dash. You can test this being the problem by running a 16 gauge wire from the battery negative to the metal shaft on the headlight switch or to the dash support frame screw holding the fuse panel in place. This ought (unintentional pun) to give a solid ground to the dash.

---Test the brown wire w/white stripe running from the alternator #1 terminal with an ohm meter. It should have a reading of 10. That's your field wire and should carry that measure of resistance if you're running stock wiring & alternator. If running a 1-wire conversion, I have no idea how this would effect the charging system, but if that wire is changed, your battery is giving a false signal to the alternator and the battery is not being charged correctly.

---After being a model citizen... or a human with a conscience, I jumped off a guy who was standing in a snow storm with his 6 year old son in the car freezing. I quickly hooked up the wires, fired up my Scout and it wasn't till after I saw the reflection of the spark under my hood and dash and he was jumped off, that I saw he had a bird's nest of wires, duct tape included, under the hood of his car. I followed them home, stalling out here and there, watching the ammeter peg out on discharge, then charge, discharge, etc., etc., lights dimming and then shining like ACLs, truck stalling... finally I got it home and it wouldn't recreate the event... then one day it did and I replaced the ammeter with a new round 2-1/4" mounted in the original gauge housing.

---I'm sure you know that if your battery was dead and you hooked a new alternator to it, you could have damaged the new alternator. Alternator has to switch off to cool down and is used to maintain a charge. Making it charge a battery like a generator, will damage it, like fry the diodes. Hope it's just somethin simple like the ground. If it is, you should plan a quality rewire & some bodywork in the near future.

_______________________________________

---Sorry, just remembered the last part of your post, but am leaving my reply as was, with an edit.

---It is possible, I think you'll have an external circuit breaker mounted to the stud on the rearmost portion of the headlight switch. Those circuit breakers are readily available & might even be cheaper in price at a local Flying J (not Petro/TA) truck stop or the likes.

[quinng]

I had the same problem after I replaced my alt and it ended up being the plug. I was not making a good contact so I replaced it and my problem was solved.

[NorCalDiesel]

Thanks, and interesting note on the circuit breaker light switch. I will look into the ground issue. Based on what I have noticed with the PO(s) electrical skills, that is probably the issue.

The battery was charged fine when I swapped the Alt or I would have put it on the charger overnight. It started right up on the first crank as usual, but it now has much brighter lights both dash and headlights.

My wiring harness has been worked over by the PO(s) pretty good. I have been thinking of getting a Painless wiring harness for the cab and front end. I have never installed an entire harness before, but it doesn't seem to difficult.

quinng, what plug are you talking about? The voltage reg plug at the Alt? Mine crumbled so I ended up just plugging the wire back onto the spade. But I made sure to plug it into the correct spade/plug. The one for a gauge and not a light.

[NorCalDiesel]

Okay, update... I went out and put the charger on the batt just to make sure. It went to full charge in less than 1 minute, so that should be good. I followed the alt wires to the bulkhead connector and it looks old and somewhat dirty, but not burnt or mangled. It looks good for 40 years old.

But the Ammeter is smoked inside the glass as if it is fried, but it seems to function. At least it appears to work, it moves with the engine rpm.

What do we replace the ammeter with? something from autometer? I would rather get right to replacing what looks fried as I begin to troubleshoot.

Thanks for all the info both in this thread and the others I am searching through.

Pat

[NorCalDiesel]

Just went for a drive once more after I checked the resistance of the field wire and a couple other wires under the dash.

Here is what I found,the field wire seems to have the correct resistance. But the ammeter pegs at C when idling and moves to D under power. It is the original gauge, but the needle is smoked black unlike the red needles on the other gauges. The battery is fully charged according to my relatively new charger. I am going to say the meter is a problem if not the problem. So I will start there

What are the replacement options that I am sure others here have used for aftermarket ammeter gauges?

Thanks,
Pat

[Thomas]

---If that ammeter is fried, I would hurry to replace it or do as other have done and install a voltmeter. I opted for a new ammeter, seeing as how the only real* issue with an ammeter is using an old one. I also much prefer seeing charge/discharge over volts anyway, plus I didn't have any issues with the way IH did it originally. After all, it's a truck/implement/piece of equipment.

---I used the PCB from the original gauge. Lined up a 2-1/4" round 60A ammeter's internals, drilled the PCB for mounting holes for the studs, scratched away the circuits on the PCB that would come in contact with the studs, created jumpers with wire & soldered, to close the circuits I broke and mounted the new gauge to the front of the PCB, using neoprene washers to completely separate the posts from the PCB. It wasn't all too hard and hasn't given me any issues with the new wiring I installed.

---I heard too many stories about Painless' customer service as well as their "universal" wiring systems so I was weary about purchasing from them... as well as that EZ Wiring company who likes to keyword spam using quailty wiring companies' names in hidden text scripted into their listings on eBay. The OEM harnesses are available from Light Line Parts suppliers as well, but at the time the only replacement fuse panel they had was OEM as well. I wanted away from the buss type (bottle) fuses as well and wanted new mini fuses. What I found was Ron Francis who is basically the founder of aftermarket wiring harnesses. I couldn't have been more pleased with the quaility and service, though pricey, it was comparable to OEM prior to my adding extra terminals & wiring kits for future upgrades. Ron took care of me on a personal basis, was even the one who answered the phone, which seemed to be normal business practice for him. The entire job was around 10 hours, from gut to start... and seeing as how I finished at 9:30 or so pm CST, when I had to call because my truck wouldn't shut off, had to stall it with the clutch & brake... lol, within 5 minutes, the Ozzie technician on the phone pointed me at the wire which I had wrongfully terminated. That was about 4.5 minutes of information to look up my purchase order, and then about 30 seconds to have me trace the red alternator wire to the orange ignition terminal (D'OH!) on my fuse panel. I can blame incandescent light for that though. Anyway, when it comes time that you want to do this, please post ahead of time so experienced fishermen can explain how to pull wires to save time & trouble.

---I'll make up a make-shift diagram of how I did the ammeter gauge. Sorry, all pics I had taken were lost when the Cornbinder.com site went down (possibly Katrina) and I didn't have them on disc.

---Here's the 2/5 of the altered gauge clusters. Not beautiful, but upgraded/new put my mind at ease as well as eliminated aftermarket clusters/pods.

[NorCalDiesel]

Thomas, thanks for your replies on this and my other post. I remembered I had a dash from an 80 that had a new aftermarket SW ammeter. It looked good inside the glass and the terminals were clean and unburnt. So I pulled the one in the pic out and replaced it with the SW. I replaced all those burnt crimp ends

That was it. I have a strong electrical system and great lighting. I was looking at that big box of rusty old scout parts the other day thinking they are going into the bin.... Glad I kept them.

Between replacing the points/cond and alternator / ammeter last night and today, She is running the best ever since I have had it running. I might just get that right side fuel tank boiled and sealed.

Also, thanks for the perspective on Painless and the rest. I am a bit hesitant since most of the under dash wiring looks original. I might just repair what I have in place and say done.

[Thomas]

---Looks crispy! Yeah, don't think you'd have to pay any attention to my comments about PCB with that, a new 2.250" 60a Ammeter would fit in your original gauge pod without fabrication... LOL.

---Sorry, haven't been able to shake thinking it's something other than a 70 Scout 800. Don't know if Light Line would have a wiring harness for that bairn, but if they did, you surely would find it here first... Straight to the top with Super Scout Specialists

---Glad you found it. The thought of a dash fire just scares the bejeebers out of me.

[NorCalDiesel]

Originally Posted by Thomas

---Looks crispy! Yeah, don't think you'd have to pay any attention to my comments about PCB with that, a new 2.250" 60a Ammeter would fit in your original gauge pod without fabrication... LOL.

---Sorry, haven't been able to shake thinking it's something other than a 70 Scout 800. Don't know if Light Line would have a wiring harness for that bairn, but if they did, you surely would find it here first... Straight to the top with Super Scout Specialists

---Glad you found it. The thought of a dash fire just scares the bejeebers out of me.

I got my LST from them along with a few other odds and ends like body mounts. While digging around under the dash today it seems pretty simple compared to later models. I am going to repair what I have along with new grounds. I have already replaced the batt cables.