perfect day for a cruise - but

[DLK]

It was a perfect day for my wife and I to participate in an all-day WPC cruise event. My Dodge cruised nicely for about 30 miles then the ammeter went into slight discharge on the highway and more (-15) with the lights and radio on. :( We turned around and headed home - for about 30 miles the ammeter showed just a slight discharge and now and then would briefly show about -15 (not running any accessories). For the last couple miles it was suddenly pegged at -40 and I started to hear a loud buzzing sound under the dash.

When I got home I crawled under the dash to try to locate the sound without success so far. There was no burning smell I am baffled as to what might be going on. I assume the buzzing sound must be from one of the gauges - they all are working. When I step on the gas the buzzing gets louder. Do I probably have a short somewhere?

[PatS....]

Bummer. I would suspect the voltage regulator on the engine side of the firewall for the buzzing. Common failure in these old Mopars.

[JerseyHarold]

If your ammeter reads screwy, sometimes whacking the voltage regulator with the palm of your hand fixes it. The same whacking repair also works for radios that hum but don't play. In both cases, it un-jams the internal contact points that are sticking.

[DLK]

Bummer. I would suspect the voltage regulator on the engine side of the firewall for the buzzing. Common failure in these old Mopars.

It's a brand new voltage regulator that came out of the box from O'Reilly on Thursday. I have another one I bought on e-bay that arrived yesterday but I wonder if I could go through 2 regulators in two weeks? I am reluctant to try yet another one.

Just to add to the mystery i went out to the garage half and hour ago and my 4 year old battery is DEAD. I mean totally dead, when I hook up the charger it pegs the needle and will not take a charge. So I am wondering what is the cause and what is the effect? I am going out now to buy a new battery but wonder if it was bad or damaged by all that was going on with my charging system.

[JerseyHarold]

Are there any generator repair shops in your area? If so, take the generator off the car and bring it in for a bench test. There may be a short in it. I'd also take a close look at the wiring to see if the insulation is off and wires are touching.

[DLK]

Are there any generator repair shops in your area? If so, take the generator off the car and bring it in for a bench test. There may be a short in it. I'd also take a close look at the wiring to see if the insulation is off and wires are touching.

Yes we do have a generator shop in town, years ago I had them rebuild the one in my 47 P-15. I agree that I have nothing to lose by having them look it over and rebuild if necessary. I am also going to trade in the voltage regulator I got from O'Reilly for another. I agree with you that the loud hum was probably coming from the regulator I just thought it was inside the car since it was on the firewall.

I don't understand the battery. It was stone cold dead and I brought it to O'Reilly. They had to charge it for 30 minutes to test it. When they did it registered 6.4 volts and more CCA than it was rated for. So why it went dead in an hour today is beyond me.

[JerseyHarold]

If there is a short circuit it can drain the battery very quickly. The buzzing you heard was the voltage regulator trying frantically to provide enough current to recharge the battery. There are no fuses on these cars (except to the radio and a circuit breaker on the headlights) so there is no short circuit protection.

One way to test for a short circuit is to turn off everything electrical in the car, and then disconnect the ground lead from the battery and put a 6-volt test light in series between the battery terminal and the cable. If it lights, you've got a current draw somewhere. The next step is to disconnect the field and armature wires from the voltage regulator and try the test light again. If the light is off, the issue is in the generator or the wires going to it. If the test light is still lit, it's time to go circuit by circuit until you isolate the one that has a short. I'd start at the battery cable connection on the starter relay and remove the circuit feed wires under the cable terminal one by one. A wiring diagram is a big help so you know what each wire controls. Hopefully this method will allow you to find where your problem is.

[Jerry Roberts]

Are there any generator repair shops in your area? If so, take the generator off the car and bring it in for a bench test. There may be a short in it. I'd also take a close look at the wiring to see if the insulation is off and wires are touching.

If you bring in your generator for testing , bring in your regulator too . Or both of your regulators .

[DLK]

Thanks not only to those who posted replies but also to the MANY prior posts on similar topics. I spent about 2 hours this afternoon reading old threads and they helped a lot too. (My wife was not happy that I was not out helping her with her gardening )

It looks like I have it resolved for now. I followed the old thread suggestion to ground the field terminal of the generator and check the ammeter - sure enough it bumped up to 40 amps. Generator probably OK.

Next I put in the regulator I bought on e-bay, a Mobil adjustable. Once I hooked it up there was no charge on the ammeter. I followed another suggestion and hit the regulator a couple times with a rubber hammer and BINGO it was working - only too good. I adjusted the regulator to reduce the output to what seems like normal.

If I still have trouble I will follow the suggestion on checking for short circuits. I don't know where us tenderfoots would be were it not for this forum and all the helpul people here!

[BobT-47P15]

Good to know that regulator you got on ebay works......I bought one of

the same brand. Haven't tried it yet.

[Cpt.Fred]

good you solved your problem so quickly!

this thread was indeed very interesting and helpful, and i wonder what those ammeters should normally read?

mine is steady around zero, sometimes a little higher. when i use the turn signals it starts dancing. but so far i never had problems with the battery or starting.

and now, i'm going to start digging around the tech section about how to adjust my regulator (i didn't know i could do so...)

[DLK]

Good to know that regulator you got on ebay works......I bought one of

the same brand. Haven't tried it yet.

I was ready to throw it in the trash and those two whacks with a soft hammer did the trick. I suppose after 60 years the points were stuck. I like the way you can adjust the charge rate with a small screwdriver without taking off the cover.

[Joe Flanagan]

Isn't it true that some regulators are not adjustable? I compared mine to the one shown in my Plymouth manual and they are very different. The one in the manual pictures an adjustable regulator. The one I have has no such features. I was told that it might have been a cheap replacement, thus did not have all the bells and whistles you'd get with a new stock regulator.

[DLK]

good you solved your problem so quickly!

this thread was indeed very interesting and helpful, and i wonder what those ammeters should normally read?

mine is steady around zero, sometimes a little higher. when i use the turn signals it starts dancing. but so far i never had problems with the battery or starting.

and now, i'm going to start digging around the tech section about how to adjust my regulator (i didn't know i could do so...)

I THOUGHT I had solved the problem. However for the past month I have been afraid to get outside about a 5 mile radius from home because of the way the charging system would stop charging from time to time. Sometimes it would be for a couple blocks - sometimes for a couple miles. Then today I took the car out to fill it with gas and shortly after I left home it quit charging and did not come back this time. I started the car a couple times after returning home - still no charging.

I pulled the generator and am taking it and the two regulators I bought to a electrical rebuilding shop. My fear is that the generator has an intermittent short that fried the regulators but might not show up on a bench test.

This has been such a frustating season. I was so looking forward to driving my car and between this problem and the still nagging turn signal issue I have been able to get very little driving enjoyment. I am extremely jealous of people with an aptitude for solving electrical issues. I found a number of useful suggestions in old leads on this board (checking grounds, tightening the wires on ammeter terminals, how to bypass the vr to test the generator to mention a few) but still have no solution. I probably should have taken the generator into the shop a long time ago.

[Cpt.Fred]

i'm sad to hear this, and i hope the people at the shop can help you out!

i'm having the same trouble with my brake system, eats up nearly all the fun.

BUT! we're going to master this and go on driving our great old cars, i'm sure;)

hang in there, summer's not over yet!

best,

fred

[greg g]

I would get up under the dash and check all the wires, especially wher they might cross and contact another wire. You mentioned that sometimes it discharges a bit and then will increas or peg, this suggests something might be finding an inappropriate ground either by crossing another wire of going directly to ground. You have already metioned the test showing the genny is OK, so it got to be eithr the VR itself or between the VR and the Ig switch or between ign and a load.

One other simple thing you can do for the health of your system is to runn a ground wire between the body and the engine/frame. Simplest is from the firewall to the engine. A couple strands 10 guage wire paired up is enough.

[Don Coatney]

Is your battery connect as positive ground? It sounds as if it is not.

[LAKOTA169]

I agree with greg. Last fall, I was out with my car. It was dusk and getting a little cool. had the headlights on and went to turn the heater fan up. when I did, my lights got dim. The morre I turned the fan reostst, the dimmer the lights got. next day, I got under the dash to check the wiring. Followed the fan wire from the switch to the motor and found that it was touching the cowl vent lever. whenever I used the lever to open the vent, it would rub the wire and wore right through. Cut out the bad wire a rerouted new wire.

[Young Ed]

Ed do we Eds have a tradition of this? When we were driving around detroit 2 summers ago I couldn't stop blowing headlight fuses. Problem was eventually traced to a wire that got too close to the clutch pedal. After a while of clutching I wore through the plastic and then it would ground out and pop the fuse. Which of course also explains why my re-wiring project all worked perfect at first and then developed an issue a couple months later.

[LAKOTA169]

It's the Detroit air. I'm about to start on a turn signal project. Have to come up with something for the front lamps. Am thinking about using cowl lamps, but mounted by the front bumpers. Rear lights will be a problem also. My RR is connected to my LR. Read somewhere that said to cut the brake light wire between the two and "terminate" it. Then connect the right signal wire to the right brake wire. If I do it this way, will the r brake lamp still work for braking? Also need to find a way to mount the flasher. It signal unit is a 7 wire from Wirth's.

Ed

the Detroit Outlaw's

[Young Ed]

A couple guys in our chapter with 30s cars have used some little harley lights that clamp nicely to the front bumper irons. One guy converted fog lights to signals too.

[LAKOTA169]

A couple guys in our chapter with 30s cars have used some little harley lights that clamp nicely to the front bumper irons. One guy converted fog lights to signals too.

Are the Harley lights 6 volt? Most lights I've seen are 12 volt, and I don't know if there is a 6 volt bulb that will fit.

[DLK]

I would get up under the dash and check all the wires, especially wher they might cross and contact another wire. You mentioned that sometimes it discharges a bit and then will increas or peg, this suggests something might be finding an inappropriate ground either by crossing another wire of going directly to ground. You have already metioned the test showing the genny is OK, so it got to be eithr the VR itself or between the VR and the Ig switch or between ign and a load.

One other simple thing you can do for the health of your system is to runn a ground wire between the body and the engine/frame. Simplest is from the firewall to the engine. A couple strands 10 guage wire paired up is enough.

One helpful suggestion I got from the electrical shop - he asked me what had been hooked up to the ground screw on my generator. The answer of course was nothing. He suggested when I put it back in the car I run a ground wire from the grounding screw on the generator to one of the mounting screws for the regulator. Since the generator has an excellent ground to the block it makes sense.

I also mentioned to him that I toyed with the idea of converting to an alternator. Having worked on many old generators he said if I stick with 6 volts he'd stick with the generator - he said the autolite's like my car has in it are really durable. What was also interesting is that he looked over my generator and said it probably had never been rebuilt since the original paint was still on the housing and in good shape.

When I get this back together I will check all the wires under the dash again as has been suggested. Most are new with new soldered terminals but I did not touch any of the stuff that was inaccessible like those running to the back of the car.

One other issue I have not mentioned in my posts (it's trivial at this point) is my instrument lights do not work. For now I am not even troubleshooting that issue since I rarely drive at night. Maybe that can be a 2011 project...