73 Bronco "Ground Issue"???

[purkey]

I've had my 73 for a little over a year now; had the wiring harness replaced with a Painless, pulled the Duraspark and replaced with a Mallory, added the Headlight Relay harness, & replaced the 2 small electric rad fans with 1 larger electric fan. Last night, after a full day at a softball tournament (and losing in the semi-final; after my daughter pitched a 1-0 ballgame on a 1-hitter with the only run due to an error) started the Bronco to come home; it was sluggish starting but it was about 40F temperature and had been sitting since 9am (it was now around midnight). Drove through McDonalds to get something to eat; noticed that my tach was running backwards, radio had quit, and the headlights were out/dash lights were dim. I pulled into a gas station parking lot to check fuses & replace the headlight relays (I had bad relays about 4 weeks ago on the headlight harness so I carry spares now). No blown fuses so I pulled the relay harness and plugged the headlights back into the Bronco harness; now I have lights. But the Bronco died and would not start; seemed like a dead battery (bought new in August 2016). Had a Cop jump me off; fired up (tach worked as it should and the radio started working again) and drove to get on the Interstate but 30 seconds later headlights went out again. Pulled over on the entrance ramp and then the Bronco died and would not turnover when trying to re-start. Decided to call a tow truck (it was now 1:30am and had the entire family with me).

the brake and side marker lights worked when the headlights were not.

Question: Does this sound like a ground issue? I'm leaning toward looking at the headlight harness since that was the most recent "issue" I was having.

Duraspark was replaced in Nov 16 due to me having to "ground" the coil wire to the air conditioner to get it to start (it would not turnover); during troubleshooting the duraspark would not get a fire from the coil (replaced coil, checked for cracked distributor cap, replaced the "box that the Duraspark was wired to", etc). The only thing that would work would be to pull the coil wire to the cap and ground; then it would fire up until after I drove it, then I would have to repeat once I turned it off and wanted to start it again. After replacing the distributor haven't had this issue anymore.

The PO added a "1-wire" alternator so I am not totally sure where to start with on this one.

Timeline of electrical replacements:
February 16 headlight harness installed
August 16 Painless installed
November 16 Duraspark pulled/replaced with Mallory
December 16 radiator fan replaced
January 17 headlights quit working; installed new harness relays and they started working again
February 18th 2017 I changed the oil; last time the hood was popped; driven for over a week with no issues
February 26th 2017 wife is pissed at me for selling a no issue truck last year for a Bronco that I drive every day

 

[B RON CO]

Hi, can you diagnose and work on this yourself, or are you looking for some direction? Here is what is see. You have a driver with no previous charging system issue. Now at night the battery is dying on the way home. Did you notice an amp or volt gauge reading low? At night with the lights Ang heat on you are putting the largest draw on the charging system, especially if you have high draw headlight upgrades. You need to see the voltage at the battery with the engine running. You need 13.5 to 14.5 volts. If the charging system is not putting enough current to the battery the battery will drain. This could be caused by a bad ground, really any loose or corroded connection, a bad alternator, a loose fan belt. Also the voltage at the alternator needs to be checked. These are the basic starting points. I have a feeling it runs fine in the day time, but the headlights are causing a major drain. Good luck

 

[purkey]

Sorry for the late reply, life got in the way. I've had, what I would consider, some charging issues over the last year; when I replaced the battery last August, it was only 1.5 years or so old battery according to the stamp on the sticker.
I do plan on looking into it: making sure I have decent ground cables and making sure I have the correct # of grounds. I have a battery - to body (under the starter solenoid), to the engine (exhaust manifold bolt), and engine to firewall (intake bolt to gas pedal linkage bracket). The last one looks like crap, so I plan on replacing that one as soon as I get around to it. For now, the Bronco will sit since I am preparing to start outage season.
If it involves anymore than that I plan on taking it to a local place that still works on older cars; 3 tows home over the last 11 months doesn't make the wife too happy.
I took battery voltage readings yesterday afternoon and got 13.5 from the + to bare metal radiator support. Took it again and it read 1399 (no period in that #). I don't know if I fried my meter or what. I had it set on 20VDC for both readings.
I was still mad so I shut the hood and did nothing else since I sad some choice words in front of it Sunday morning (post tow) and Sunday morning (after waking up).

 

[DirtDonk]

Don't read at the core support. Just read from the positive and negative battery posts. This is where you will see just how much is reaching the battery. Your core support has too much possibility of being in poor contact with the rest of the body.
If you still get 13.5 volts, check again with some loads on it, such as the heater and headlights on. If it goes down, your alternator is not charging sufficiently. In fact, even though 13.5 is "acceptable" in a pinch, you should be seeing in the high end of RON's range, more like the 14.5 instead.

Don't use an exhaust manifold bolt. Too much rust and heat. Personally, I would just replace that cable with a new one just in case the heat has compromised it. I don't know how much they can take, but an exhaust bolt is maxing out any components acceptable range. And then some!
Instead connect the new one (4ga or larger) it to the engine block away from the exhaust manifold. There is a threaded hole on some blocks just in front of the starter. There are also other holes near the front of the block and the heads.

If your throttle linkage is painted and the body painted, maybe you should try a different spot for the body ground. Or make sure the contact surface is clean bare metal.

Test your battery too. Those that don't get driven much do tend to go bad earlier than one that's driven and charged daily. But some can just be defective. I just replaced a good expensive battery under warranty. Almost exactly 2 years and it was dead and gone.

It's more likely that the low battery voltage is messing with the other stuff like the headlight relays, electronic ignition and such. Rather than them messing with the battery. And no way is your headlight system going to kill the battery if everything else is working properly. But insufficient voltage to the ignition will sure kill things dead.

Good luck.

Paul

 

[DirtDonk]

And like many others have found recently, if you still have V-belts running things, make sure they're tight.

Paul

 

[ransil]

Check charging system with a load on it, heater on headlight on high radio and electric fans on.
Then work on the grounds, I like a welded stud on the fran and body ( inner fender by spring tower) then connect Batt-block and the block to frame & Body block needs to be clean bare metal, alternator mounting to bracket to block also need to be clean bare contact points

Tip:
Never rely on a Bronco for daily transportation

 

[purkey]

I sold a reliable 02 F150 to drive this as a daily driver.

I've been in contact with a CB member that lives close to me so I have some ideas of where the grounds should be checked/replaced. Now I just have to find time to do it.

Thanks for all the replies.

 

[DirtDonk]

There really were only two grounds from the factory. But yours is no longer factory.
The key is adding your own new ones, if it hasn't been done already by you or a previous owner when the new harness was installed.

Just make sure that the main cable goes down to the engine block. Nearer the starter is better.
Make sure that you have an additional ground to the body from the battery.
Add your own ground between the engine and firewall. Add another between the engine and frame.

Always make sure to clean any paint or rust off when you're connecting. Then for long-term reliability, just a quick shot of spray paint over the top will keep rust to at least a minimum compared to leaving it bare.

It sounds like you have multiple problems related in part to the harness install and partly to some of the other components as well.
If it's truly a "1-wire" alternator, then to get it to charge at all you have to rev the engine up to about 1500 to 2000 rpm initially after starting. Once there, the alternator self-excites and turns on. From then on it's able to charge until you turn the engine off. The it turns itself off as well.
If after blipping the throttle you're seeing 14.5 volts at the battery, then it's at least capable of some work. If turning things on starts to lower the voltage though, either the alternator and/or regulator are bad, or one of the connections is bad.

We're going to need to see some pics of your setup I think. A general engine compartment shot, some close ups of the alternator, and anything else you think pertinent. And some you don't think are pertinent even.
It's just too hard to diagnose so many odd issues from afar. Yes, when you get weird things going on, it's often some sort of grounding issue not letting the power complete a full circuit. But yours sounds a bit odd no matter how you look at it.
So pics first, then some more diagnosing.

Paul