Electrical Problems / Won't start!

[darks76]

My bronco has always had some electrical problems. The battery always seems to drain when its running and now it won't even start up. I've tested the alternator, I've tested for shorts in the system...tested and retested.....and retested.
I have a brand new starter, new starter solenoid, fully charged battery, sorta new volt. regulator, a functioning alternator. I just dont see where the problem is.
Maybe its one of the diodes on the alternator...but I've brought the damn thing to PepBoys to have it tested and it works just fine. ???

Any advice????

 

[66horse]

Ok so it wont start, what does it do, if anything? Noises, turns over but doesnt fire, just clicks?

 

[Dennis]

Just clicks, replace batt. cable. You can verify which one by using jumper cables for each length of cable.

If it cranks but doesn't fire, keep in mind the two parts of an engine, fuel and fire.

 

[Nuke]

So is this a starting problem or a charging problem. Your titile suggests a starting problem but you text says otherwise.

It seems like you have a charging problem. First check your battery connections. File/Sand them a little to get a better connection. You might have blown you reg--real common thing to do when testing electrical problems. The manufactor suggests NOT removing the neg battery cable while the engine is running: this is a common bad practice when people are diagnosing charging problems.

I wouldn't trust the auto store people to diagnose this old regulator charging system. If you think its your alt, take it out and have them bench top test it.

 

[BwoncoHowie]

Dark76,
What kind of voltage is in the system when the engine is running?

Should be 13.8V to 14.6V @ 1,000 RPM, with the accessories off depending on the condition of the battery. When you first start it, the voltage will be higher and then taper off as the battery recovers from cranking and gets closer to full charge. Those voltages are the normal average on most of the vehicles I have tested with good batteries, and will vary slightly depending on battery condition and the calibration of the voltmeter being used.

If you need to replace any battery cables, find a parts store that will supply you with 1ga. cables, often referred to as 6-volt cables. Also make sure that you have good ground cables going from the engine block to both the body and battery. Just some things I would check first... BH

 

[darks76]

[quote author=BwoncoHowie link=board=5;threadid=15589;start=0#msg117971 date=1048532905]
Dark76,
What kind of voltage is in the system when the engine is running?

Should be 13.8V to 14.6V @ 1,000 RPM, with the accessories off depending on the condition of the battery. When you first start it, the voltage will be higher and then taper off as the battery recovers from cranking and gets closer to full charge. Those voltages are the normal average on most of the vehicles I have tested with good batteries, and will vary slightly depending on battery condition and the calibration of the voltmeter being used.

If you need to replace any battery cables, find a parts store that will supply you with 1ga. cables, often referred to as 6-volt cables. Also make sure that you have good ground cables going from the engine block to both the body and battery. Just some things I would check first... BH
[/quote]

I've got the beast running, it looks like my positive battery cable went bad over the winter, but with the new one on it starts fine----but with the new cable I'm still getting only 12.2V at idle. There's definatley something wrong with the charging system --- its just that I've checked the alternator, they say its good---but I still slowly lose charge on my battery when I run the engine. Sound like anything???
Thanks for your help
Jim

 

[66horse]

I recently had this problem. Check all your wiring form the regulator to the alternator adn everyhting else formt he regulator. I didnt fix it I just upgraded to a 3g. Was fairly cheap to do with a junkyard 3g.

but on your problem, if I remember right there is a wire from the positive side of the starter solenoid to the regulator. I cannot tell you what this does for sure but on another members bronco (had a centech so color could be different), it owuld not charge without this wire hooked up. He had checked alt , new reg and had same problem as you. As soon as we hooked up this wire, started charging great. Cant tell you what the wire is for sure but seems to me it tells the regulator to tell the alt to start charging.

 

[darks76]

What is the voltage at 1,000 RPM's ?

It sits right at 12.2V at 1000 RPM's 12.0 with the lights on.
When I turn it off--it goes up to 12.5-12.7V

 

[darks76]

[quote author=66horse link=board=5;threadid=15589;start=0#msg118025 date=1048543723]
I recently had this problem. Check all your wiring form the regulator to the alternator adn everyhting else formt he regulator. I didnt fix it I just upgraded to a 3g. Was fairly cheap to do with a junkyard 3g.

but on your problem, if I remember right there is a wire from the positive side of the starter solenoid to the regulator. I cannot tell you what this does for sure but on another members bronco (had a centech so color could be different), it owuld not charge without this wire hooked up. He had checked alt , new reg and had same problem as you. As soon as we hooked up this wire, started charging great. Cant tell you what the wire is for sure but seems to me it tells the regulator to tell the alt to start charging.
[/quote]

Thanks for the tip, I appreciate it---I'll check it out....that is if I can trace out that mess of spagetti under my hood

 

[BwoncoHowie]

[quote author=darks76 link=board=5;threadid=15589;start=0#msg118026 date=1048543729]
What is the voltage at 1,000 RPM's ?

It sits right at 12.2V at 1000 RPM's 12.0 with the lights on.
When I turn it off--it goes up to 12.5-12.7V
[/quote]

If your alternator is putting out on the test bench then the regulator or related wiring is probably the cause.

Make sure the "I" terminal on the voltage regulator is getting 12V when the ignition is turned on. and make sure you have clean, tight, connections at the regulator and the back of the alternator. Check closely for broken wires between the alternator and the regulator. The field connection between the alt and the reg is important. The alt field terminal can be white or orange insulating ring and it's the terminal closest to the center on the back of the alternator. If this happened to me I would be real ready to try another regulator if the wiring looked good. BH

 

[Skuzzlebutt]

I've taken numerous alts to parts stores for testing and they always say "good" and they always are wrong! I know many people with the same experiences.

Whoever said to not pull a battery cable to test the alt was Right! That worked fine for generators and dynamos 40 years ago but it can easily ruin an alternator.