74 Bronco All original stuff I need help with

[74BroncoLV]

Hi All,
A few questions....1974 Bronco Uncut all original and pristine condition. 26,900 original miles on all original equipment.

I am in Las Vegas and its hot.....

1. The battery was replaced a week ago, the alternator replaced 1 day ago...alternator still does not charge the battery. Voltage regulator? I cant think of anything else in the loop it could be.

2. Engine knocking (idled for awhile in 107 degree heat) then drove about 5 miles then idled in garage...knocking still there and lots of whiteish blue smoke at idle. Today no smoke or knocking.

3. Headlights...they turn on fine, play with the knob by jiggling it and the dash lights will come on. Hit the floor hi beam switch they come on....when hit the floor switch again to turn off hi beams the low beams dont come on....then you play back in forth with dash swich and hi beam floor switch and you can get them back on.

This is a gorgeous showroom truck and I dont want it to caput! any help appreciated......

I have owned it 1 month...I asusme it sat quite awhile before that in a climate controlled garage though (thank God)

Scott

 

[Timmy390]

1. My guess is the voltage regulator but the altenater might be bad as well. Those reman units can last days or years. It's like rolling the bones when you buy one. Take it to your fav parts store and get it tested. I would look for cut wires. Why, MICE/RATS.......

2. Knock or tap? Knock tells me rod bearing, tap tells me stuck lifter. Oh and my 302 has that crank knock that people talk about due to the firing order. You can tell it's not a rod knock it's more blunt and only hear it at idle. Blue smoke is oil. If it sat for a while, I would expect that. Leaking valve guides my guess.

3. Sounds like the headlight switch is old and the contacts are junk. Could be bad wires (mice and rats) too. You can get a new switch at any parts store.

It's hot in AR too. 105 yesterday.......

Tim

 

[hc37180]

Have you done any voltage tests to see where how well your new parts are functioning? Easy enough to make sure your new Alt is working properly. Most auto parts dealers can come out and trouble shoot right at the car if you don't have the equipment. Also I know heat can have a huge impact on wire integrity and conductance so maybe check for bare/exposed wires.

Otherwise I am not sure but you may have an incomplete circuit somewhere (ground?) and from the weird things happening with your headlights this may just be an overall harness issue. Any idea how old it is, or been replaced?

My knowledge is not immense on this subject but these 2 areas would be where I would start. Believe it or not Youtube has some great videos on troubleshooting different electrical issues etc.

 

[74BroncoLV]

thank you so much....
so the smoke and engine knock I should? do what?
the alternator was tested right when it was put in and nothing...
I have the voltage regulator ready to install tonight.

even if the battery is draining from a bad ground the alternator shoudl still charge it while driving so those could be sepaprte issues right?

what exactly does a voltage regulator do? looks easy to replace and cheap enough....

shoudl I not be driving it with the knocking and occasioanl smoke?

 

[hc37180]

thank you so much....
so the smoke and engine knock I should? do what?
the alternator was tested right when it was put in and nothing...
I have the voltage regulator ready to install tonight.

even if the battery is draining from a bad ground the alternator shoudl still charge it while driving so those could be sepaprte issues right?

what exactly does a voltage regulator do? looks easy to replace and cheap enough....

shoudl I not be driving it with the knocking and occasioanl smoke?

Sorry not much to offer on the knocking but if I understand electrical circuits it seems plausible your break in the circuit could exist between the Alt back to the battery. I base that on the notion if the Alt is putting out the right amount of voltage then the battery should be getting charged. Is the voltage enough for the demand from your rig and any extras? Big Audio system, A/C etc...

 

[74BroncoLV]

its a one day old altenator, the cables seemed ok....but still no charge to battery....I guess the last thing is the external voltage regulator right? what does it do?

 

[74BroncoLV]

OH...and yes a new AC and no big stereo

 

[Justafordguy]

The voltage regulator is what tells the alternator when to charge. If it's bad you will get nothing out of the new alternator.

 

[74BroncoLV]

sounds promising....thank you

 

[70_Steve]

sounds promising....thank you

If/when you install a new voltage regulator, mount it to the fenderwell first, then attach the wiring. The regulator is grounded through the case, and you can FUBAR the regulator by connecting it to 12V without the case being grounded.

 

[74BroncoLV]

great advice I will keep you posted...

still worried about the knocking, anything anyone suggests to tes? listen for? oil change? additives?

 

[Justafordguy]

Is the knocking coming from the top or bottom of the engine?

 

[74BroncoLV]

i will check but I think top....i will confirm later.....assuming either can you explain both situations

 

[Justafordguy]

Yep, but you should hope for top.;D

 

[DirtDonk]

Regarding the knocking, at this point the best thing you could do is drive it.
If it hasn't had the oil changed by you yet, do that right away. Oil is not only about mileage, but time too. So if you didn't already change the oil automatically when you bought it (or know for a fact that the PO did it recently), just do it.

Personally, all bad experiences by others aside, I swear by modern snake-oils when it comes to fixing low-mileage/low use engine issues.
And I don't hesitate to use two different types at the same time. In other words, use a thickener like STP or Motor Honey to help with any loose tolerances in bearings to see if that quiets down the knocking. It's not a cure, but it is a good Band-Aid to help you get by for now.
If the sound goes away, but comes back after the next oil change, oh well. It's just time to get in there and fix something. If it goes away and never comes back, you're golden and whatever the issue was, was resolved by extended driving.
At the same time, I would use a thinner solvent-based additive such as Berrymans or JB or Marvel Mystery Oil (always hated that name. Talk about the epitome of a "snake oil" name!) or one of the twenty or so others you commonly find at the auto parts store. This is to treat the symptoms of the smoking. If it's just stuck rings that need a little freeing up and driving to bed in to the cylinder wall again, your smoke should go away in a few thousand miles or less.
If it's something more serious, such as actual wear and tear on the engine, then the additives are not going to work. But at least you didn't tear into your engine for a stuck ring.
I look at it like this. If they work (like they always have for me) then fantastic. If they don't, then you're only out twenty bucks or so and you move on. I consider them part of the "diagnostic tools" available for our use.

Paul

 

[DirtDonk]

Oh, and regarding the charging issue. What are your exact symptoms? Is it dying after driving it for awhile, or is the battery draining overnight?
Either one can still be the charging system, but would be different aspects.

If you don't have one already, for a 10 buck investment you can get a very decent little volt/ohm meter for your use in tracking down electrical gremlins. With an almost 40 year old truck now, with who knows how many little "fixes" by PO's, it's a very handy tool.

With such low mileage and good condition, I would have to hope that your ammeter still works in the dash. Can you see it move up when you start the engine and down when you apply loads with the engine off?
If so, what does it read most of the time?

If not sure, try this test. With the engine OFF, turn on the headlights. The needle should jump to the negative side a couple of degrees. Heater motor on, a few more degrees into the negative.
If so, at least it's hooked up and working.
When you start the engine, you should see the needle jump negative for a split second, then as soon as the engine is running, it should jump to 20 or 30 amps positive for a few moments. Then, as the battery charges, you'll see the needle slowly go back to just above zero.
Doing any of that?

Next, with you (new?) volt meter, check the battery charge with the engine off and then on. With it off it should read in the 12 volt range (11.75 to 12.5 or so) and with the engine running it should read between 13.5 and 14.5 volts.
If so, then the alternator is charging correctly. Any less than 13 and either there's a big load on it somewhere or the alternator is not charging.

I would for sure change the regulator at least. Even though I often replaced an alternator without the regulator, it's always been a recommendation to do them both at the same time.

With the regulator's connector unplugged, check the readings at the three wires.
Green w/red should have zero volts when the key is OFF, and full battery voltage when the key is in RUN.
The Yellow wire(s) should have full battery voltage at all times
The Orange wire should not have any voltage when the engine is off.

If any of those are not what I said, then you have a wiring or alternator issue somewhere.
There should be a plug near the alternator on your '74 that has the main charge wire (or both of them?) going through it. These are Black w/yellow and Black w/red and are slightly larger than the rest of the wires. If you can separate this plug (they're pretty stuck together usually) you can test for voltage at the connectors as well.

If the problem is the battery draining overnight, then either the regulator OR the new alternator could be causing the issue. Since it was doing it before the new alternator went in, it's a good bet that it's the regulator.
Either that or you have some unknown drain somewhere like an aftermarket stereo, a cut wire lightly shorting out on something, a hidden light that's not going out, or some other weirdness going on.

Good luck.

Paul

 

[DirtDonk]

Almost forgot the headlight switch.
Just change out the floor mounted dimmer switch first. They get pretty beat up in any Bronco, so are the first choice when going down the list.

Since the highs and lows do work at times, it's not the headlights themselves. So it's either one of the two switches, or some wires here and there.
I still say change the old floor switch anyway, but keep digging for any funky looking wiring just in case.

Paul

 

[74BroncoLV]

thanks for the ideas....back to charging system....
new alternator new battery new voltage regulator.....installed within 3 days....
still no charging happening ever....now what?

 

[74BroncoLV]

no charge still

ok in the last few days....

new battery
new cables
new alternator
new voltage regulator

all connections seem fine

still no charge from alternator.....

 

[74BroncoLV]

Hey DirtDonk,
I just read your reply.

the ammeter is working....the battery drains while driving to about 11.78 (i chardge to 12.5 before i drive)

the ammeter never goes positive but goes "down" as you turn things on...AC, headlights etc it will go hover over 0 or close to it but NEVER above 0.

it does not seem to be draining overnight where you leave it from driving is where it stays...

i have tested with voltmeter idle and no idle reads the same so the alternator is not doing its thing,

i did put the new regulator in with high hopes and nothing,
I have not tested the regulsator with the voltmeter as you suggested yet....

all wires seem ok....but i can double check

ugh this is making this beautiful piece of art usless to me ego to be able to drive it on the LV strip and get head turns this week HAHAHAHAHA