electrical is baffling me-help!!

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john27pa

john27pa

74 360/904 Duster
Joined
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DuBois PA
Ok- 75 Duster s6 with a/c. First problem- alt is constant 14.5 charge. I used electrical spray clean on bulkhead area. Alt gauge used to be pegged full charging- now at maybe 1/4 charging. Once I cleaned all that up- kept blowing headlights out- now with just battery on no key in ign, my horn blows and my dash brake light is lit. I disconnected horn before headache came around. Brake light stays on with or without key in. When I insert key and turn to "run" the brake light goes out. When I start the car- you can see the brake light in dash dimly light, car starts, and brake light stays off.
Is this a bad ground? Bad ign switch-no problem starting-ever. Or ???
Here is another thing- drove the car 400 miles with it saying it was way over charging yet nothing bad happened. New Battery, new ign control unit, new alt, and new volt reg. It was overcharging bad- Im thinking it was the alt gauge wire in the bulk head- since it is/was in bad shape. Both the black and red wires there def had some heat issues before.
Im stumped??!!
 
You could have a bad regulator

You could have a situation where the regulator is not really seeing the battery negative (ground)

You could have a situation where the "sense" (ign) terminal on the regulator is not seeing the battery voltage, due to a harness connection problem

to determine what's what,

Run the engine and make these tests first with the battery "up" first with all accessories off, and again with headlights, heater on, and the engine running at an RPM to simulate 'low to medium' cruise.

With the engine running as above, stick one probe of your meter directly onto the regulator case. Stick the other probe directly onto battery negative post. You are looking for a VERY low reading, the lower the better. Zero would be perfect, more thatn .2V (two tenths of a volt) is too much. If this is high, run a better bonding strap from the block to the firewall, or at least about a no10 from the block to the regulator mounting bolts. Make sure they are clean, and use star washers

Now check the positive end. You may have a voltage drop in the harness. Once again, with engine running as above, stick one probe as close as you can get to the regulator ign terminal (blue ignition run) and the other probe directly onto the battery positive terminal.

Once again, over .2V is too high. The path is the blue "ign run" wire, from the IGN terminal on the regulator, through the bulkhead, to the connector on the ignition switch, through the switch contacts, back out the switch connector, back out the bulkhead, to the main connection on the starter relay. ANY bad connection in this path can cause this problem

If both these check out, have the battery checked for a bad cell, and then change the regulator.

WHAT ARE YOU USING to determine the charging voltage, and where is it connected?
 
"Once I cleaned all that up- kept blowing headlights out- now with just battery on no key in ign, my horn blows and my dash brake light is lit."

You have an overcharge condition that may have melted the wires in the bundle under the dash together creating the problem with the horn and the brake lights being on. The bundle that carries the hot from the alt to the ammeter needs to be taken apart/opened up and looked at. I bet some wires have melted together and are cross circuiting.

I have dealt with this issue before and you need to correct the voltage regulator issue. Your grounding is the issue. And your regulator is probably shot now as well. When you rev it up to 2500rpm how many volts are you getting across the battery terminals/cables?

This problem will eventually cause the battery to boil and blow acid out the vents.

Run a dedicated ground from the battery to the regulator ground wire and terminate on the firewall under the ground screw. Also the bulkhead connection is a major source of problems...consider running a new wire from the alternator to the ammeter and bypass the bulkhead altogether.

.02

Mop
 
I see a clue here in the horn blowing. Your avatar says /6 to 360. Did you plug a V8 wire harness into your car? If so, what year was the donor from? If I recall correctly, earlier wiring harness moved a couple circuits around on the connector and the horn was one of them. If you need a wiring diagram, look here.

http://www.mymopar.com/index.php?pid=24
 
havent got the 360 in yet- still a slant 6.
Im getting the 14.5 at the battery posts. Doesnt really seem to matter at rpm level. If anything- seemed to go down a hair at higher rpm. I do have a wiring harness out of a 74 valiant, but that harness doesnt have a/c. Is the a/c stuff just a plug and play into the non a/c harness?

I see alot about that wire loop for the dash ammeter gauge. I think I will just direct splice it and reroute outside of firewall.
I will do the suggestions you all gave over the weekend. Keep the thoughts coming!
Thanks!
 
what voltage reg do you have in it? there are constant output ones for racing that charge like that...
 
I agree with momoparman you need to take tha harness out and look at the wires. Things will not get better. they will only get worse and probably cause a fire. I have seen the amp guage wires do excactly as he is stating.
 
Ok- update. I took the red and black alt gauge wires that run through the firewall block and "ripped" them out of the sockets they were installed in. Took the dremel out and drilled the connector holes out and slid the new wires through. That way, I am still using the same holes to where they are supposed to run- so no questions later of- what the h%ll are these wires going to?? lol. I still am showing 14.6 volts at the battery- no matter what rpm's Im at. So not sure if thats right or not. Redid the battery ground-the smaller wire (10 gauge) as the prev owner had it under the rad frame bolt. I put it in the same place as the factory headlight ground spot- true, its in the rad support-front header panel??, but it works good and its a factory spot. My dash brake light doesnt come on when the battery is connected now. Horn doesnt work though, but the horn relay behind glove box clicks when pushing horn. Hmm, looked behing there- thats where the wires got fried together at. So, have to replace those wires. Maybe this is why alt is still charging battery at 14.6 volts? If it doesnt rain tomorrow, will be going out and replacing fried horn/ heater wires and putting in other volt reg I had from before. Hopefully I can use wire harness from other spare dash I have. I have a/c and other dash dont- so not sure if I can use spare wires yet. Man- that was long lol Oh- dash gauge is showing a small charge now-n just past center marks.
Thanks everyone very much! If I am missing something or any ideas any might have for other probs still being fixed- chime in.
 
14.6 is not that high. The PROBLEM is you were describing blowing out lights, which indicates that the voltage was a HELL of a lot higher than that AT SOME TIME. You may have or have had some short/ loose/ bad connection that allowed the alternator voltage to go way up.

Your description of other problems complicates the issue

You may have/ be "fixing" the problem without knowing it during your rebuild of the bulkhead connector.
 
Why do you think 14.5 volts is bad? That is normal voltage. A "12 volt" battery is really about 13.2 at full charge (unloaded). To charge a battery you have to have higher voltage otherwise the electrons will not flow to the battery.
 
slant6/4speed said:
Why do you think 14.5 volts is bad? That is normal voltage. A "12 volt" battery is really about 13.2 at full charge (unloaded). To charge a battery you have to have higher voltage otherwise the electrons will not flow to the battery.
Click to expand...

The problem is NOT the voltage reading he posted. Read the rest of the post........... Anytime you are blowing up light bulbs, more than an occasional burn-out--this means whether you are staring at the voltmeter or not, you have an overvoltage condition.
 
john27pa said:
Ok- 75 Duster s6 with a/c. First problem- alt is constant 14.5 charge. !
Click to expand...
Thats not a problem-14.5 is a good voltage.
john27pa said:
I used electrical spray clean on bulkhead area. Alt gauge used to be pegged full charging- now at maybe 1/4 charging.
Click to expand...
Thats good now-a 1/4 is a ok charge rate.[/QUOTE]
john27pa said:
I cleaned all that up- kept blowing headlights out- now with just battery on no key in ign, my horn blows and my dash brake light is lit.
Click to expand...
OK you moved the burnt/melted wires around when you cleaned the bulkhead connector. This caused problems.
john27pa said:
I disconnected horn before headache came around. Brake light stays on with or without key in. When I insert key and turn to "run" the brake light goes out. When I start the car- you can see the brake light in dash dimly light, car starts, and brake light stays off.
Is this a bad ground? Bad ign switch-no problem starting-ever. Or ???
Here is another thing- drove the car 400 miles with it saying it was way over charging
Click to expand...
What is "way over charging?"
john27pa said:
yet nothing bad happened.
Click to expand...
If nothing bad happened then why do you think it was over charging then?
john27pa said:
New Battery, new ign control unit, new alt, and new volt reg. It was overcharging bad- Im thinking it was the alt gauge wire in the bulk head- since it is/was in bad shape. Both the black and red wires there def had some heat issues before.
Im stumped??
Click to expand...
 
The burn out lights can be as simple as a bad battery connection, loose ground or positive cable can cause it.
 
I had my horn go off like that when my ammeter was pegged right, had to disconnect the horn and drive slow home :p. put in a different alt and it fixed the prob. thankfully I see no signs of fried wires.

I like the way you "bypassed the bulkhead" without making the wires go outside their normal path. I bypassed my bulkhead in that circuit but sent the wires through the speedo hole, given I will remember this, it shouldnt be a problem.

you doing well, keep it up.

if I may, whats this battery ground wire you speak of? picture?
 
I thought I remember seeing that "race only" volt reg were at 14.5? Maybe I was wrong- thats why I was thinking it was high. Its threatening rain now and my garage walls and roof leak like theres nothing there- wait- thats because I have no garage walls or roof lol. I know as soon as I go out to work on it- then it will rain like #$%^! Anyway...

1969dodgedartgt- the battery ground wire I was meaning is the 2 wire ground that goes from the battery to block and then the smaller wire from battery post to body??.

Now that I am getting on the upside of this problem- time to look for rear quarter patch panels for it so I can get her inspected. Slowly getting what I need to give her the stronger muscle of the 360.
 
Slant6'4 speed- Im thinking the same- bad ground. The fusebox was getting real high volts and hot as h#ll. The headlights would work till I either hit a bump or -now that I think about it- curves and hard turns. $40 in headlights later....

Anyone know of a kit to make the headlights into halogens like the 9004's or H4 bulbs? I did this to my Porsche 944 and love it. It just runs battery power to 2 relays then out to bulbs. That way you dont use old factory wiring for the extra juice. I saw a wire set from year one?? but they want over $100. Made a big difference on the '84 944 I have. Unless someone has a diff suggestion? Oh- been running these on the other car for 5 years now with no prob and its my daily driver.
 
john27pa said:
Anyone know of a kit to make the headlights into halogens like the 9004's or H4 bulbs? I did this to my Porsche 944 and love it. It just runs battery power to 2 relays then out to bulbs. That way you dont use old factory wiring for the extra juice. I saw a wire set from year one?? but they want over $100. Made a big difference on the '84 944 I have. Unless someone has a diff suggestion? Oh- been running these on the other car for 5 years now with no prob and its my daily driver.
Click to expand...


slantsixdan on here is a lighting engineer, he would likely know all there is to know on such things and have a strong opinion to boot :p He sells some headlights
http://danielsternlighting.com/

http://www.allpar.com/fix/electrical/headlights/index.php
 
Ok- finally have it just about back to good working order. I did have a problem with the horn thing though- funny story haha. After cutting all the loom tape off the harness-everywhere, following wires to find any other melt through spots from horn wires- I got all that fixed up. Thinking everything was good to go- no wires shoreting out, better grounds, etc- I hooked the battery back up- no horn! Hmm- I can hear the horn relay clicking- why no horn??? So, I went through everything again, found nothing wrong and didnt do anything really. Hooked battery back up- no horn blaring- woohoo! Pushed horn button- no sound! WTH??!! Rechecked grounds, wires, etc. Thought- relay is clicking- so that should be good!- WRONG! Took relay out of spare dash- horn works perfect! Im glad I like the car- or it would be out to pasture with a bullet hole! haha. Also put different speedo gauge cluster in just to see if it made any difference on alt gauge. It didnt. Maybe tomorrow- will redo all other grounds- just because. Get new headlights in her and try it out. Next step- find rear quarter patch panels and then get her inspected.
 
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