Help with electrical problem.

[Jmccormic001]

I have a 1995 Bronco with a 5.0 that won't start. I went out one day and the battery was dead so i charged it and it was still dead. i took it to a auto parts store had them charge it and they confirmed it was dead so i replaced it.

i drove it for a few days with no problem, left it over the weekend and come Monday it wouldn't start. i pulled it out and recharged it. i put it in and tried to start it. it tried to turn over then all power was lost. nothing worked. looked at relays jiggled a few and after about 5 minutes i tried again and the same thing it clicked then all power lost and it never came back.

i really would like a few tips to look for as I'm trying to get this going in the hope i will finally be starting back to work in the next week.

All help will be greatly appreciated.

Thanks you. JVMc

 

[Rons beast]

Hey JVMc,

Welcome

Replace the ground. These vehicles are notorious for faulty ground wires from battery to the engine block.

There is a clamp about half way down the cable that ground to the frame. This is important to attach too.

While you are at it check all other connections.

Good Luck

 

[Bully Bob]

Hi JV.,

Couple questions;

1) Any records as to the age of the first batt. ?

2) What kind on home charger RU using..? (most have indicator windows showing the rate & completion of charge, & AMP settings)

3) What brand of new batt. did you buy?

4) Do you have a voltmeter..? ($3-$5 at the discount stores)

Like Ron says, cables are suspicious but a voltmeter gives indication as to batt. condition. (you can also view the voltmeter in the dash cluster.)

If the batt. drops below 12V at rest in the vehicle.., there may be something stuck on or a short.

If the batt. is up to spec. & cables are good.., could be a dying starter.

You can also test for voltage draw with vehicle at rest.

 

[miesk5]

yo;

as BULLY BOB advised on voltage draw or short;

Parasitic Current Drain; Diodes inside the alt could be shorted, thus causing drain, but the it would still put out 12 Volts, and pass the Voltage Output Test, however it could not put out full current, and would fail the Current Load Test.

Remove & Charge Battery and take voltage reading (should be around 12.6 volts). Disconnect alternator, then re-install battery for a day or so & then check batty voltage again; if no drain, then diodes are prob the issue. or Take alt it to a parts store where they can BENCH-test it for free. BTW, The voltage should be between 13.0 and 15.0 volts w/engine idling.

Source: by miesk5 at Ford Bronco Zone Forums

Parasitic Current Drain Test Video, General

Source: by Eric at youtube.com

Parasitic Current Drain Test in a 96; "... Typically, a drain of approximately one amp can be attributed to an engine compartment lamp, glove compartment lamp, or luggage compartment lamp staying on continually. Other component failures or wiring shorts may be located by selectively pulling fuses or disconnecting fuse links to pinpoint the location of the current drain. When the current drain is found, the test lamp will go out or the meter reading will fall to an acceptable level. If the short is still not located, after checking all the fuses and fuse links, the drain may be due to the generator. The current reading (current drain) should be less than 0.05 amps. If it exceeds 0.05 amps it indicates a constant current drain which could cause a discharged battery. Possible sources of current drain are vehicle lamps (underhood, glove compartment, luggage compartment, etc.) that do not shut off properly. If the drain is not caused by a vehicle lamp, remove the fuses from the interior fuse junction panel, one at a time, until the cause of the drain is located. If drain is still undetermined, remove fuses one at a time at the main fuse junction panel to find the problem circuit. Check for current drains on the battery in excess of 50 mA with all the electrical accessories off and the vehicle at rest. Current drains can be tested with the following procedure; DO NOT ATTEMPT THIS TEST ON A LEAD-ACID BATTERY THAT HAS RECENTLY BEEN RECHARGED. Do not crank the engine or operate accessories that draw more than 10A. You could blow the fuse in the meter. Many computers draw 10 mA or more continuously. Use Rotunda 88 Multimeter 105-R0053 or equivalent between the battery positive or negative post and its respective cable. NOTE: Steps 1-5 correspond to the numbers in the following illustration. Insert the test leads in the input terminals shown. Turn switch to mA/A DC. Disconnect battery terminal and touch probes as shown. Isolate circuit causing current drain by pulling out one fuse after another while reading the display. Current reading will drop when the fuse on the bad circuit is pulled. Reinstall fuse and test components (including connectors) of that circuit to find defective component(s)..." READ MORE Source: by miesk5

Parasitic Current Drain Test; "...you should be able to trace the "parasitic draw" on the battery in the normal way. Pull the (-) cable off & put an ammeter inline set to the 10A range (or higher if possible) to see how much current is being pulled out of the battery with the key OFF, the doors SHUT, & the hood light bulb REMOVED. Make sure absolutely NOTHING is turned on anywhere on the truck. If it registers 0 or below the meter's next range, switch it down a range until it shows some useful numbers. If it ends up being below 0.5A (500mA), then replace the battery. If it's above that, start by disconnecting all the alternator wires & see if the reading drops under 0.5A. Then move to the fuse block & pull them 1 at a time until there's a significant drop in the reading. That's the circuit that's draining the battery. Follow it to find the problem..."

Source: by Steve