WONT START PLEASE HELP

[wes912]

i just bought a 91 bronco 302. my brothers battery was dead so he tried to take mine out while running and put his in to charge it up a bit, he got the neg hooked up to his battery and when he touched the pos cable to pos terminal truck shut off. now it will only turn over but wont crank. checked all fuses in cab but no luck. any ideas

 

[miesk5]

yo WES,

WELCOME to da ZONE!

Does Horn & radio work in accessory position?

Do headlights come on at all?

If you have a multimeter, get a reading of batty voltage w/everything off; should be at least 12 v

Then have some crank engine and get another reading; should be at least 9.6 V whie cranking in warm weather,

Dirty or loose battery cables: Clean and tighten cables - including grounds

Locations in a 90; "...G100 LH side of Radiator support; G101 RH side of Radiator support; G102 RH side of Radiator support; G103 LH rear side of engine near knock sensor; G104 LH rear side of engine compartment, near electronic engine control (EEC) module, on the left fender close to the firewall; G105 LH Side of engine; G106 RH fender apron, near voltage regulator; G107 RH fender apron, at starter relay; G108 RH fender apron, at voltage regulator; G109 RH fender apron; G201 LH rear side of I/P (looking at the diagram it is at the bottom of the driver's side dash assembly. Screwed to the bottom edge, just to the left of the steering column. It is the ground for the instrument cluster); G202 Behind RH cowl panel; G203 RH rear side of radiator support; G204 On steering column; G205 Behind Center of I/P (Dash); near speed control amplifier; G400 LH side of cargo area; near rear light assembly; G401 Below LH side of cargo area; near crossmember; G500 Inside driver's door; near left door speaker"

Source: by BroncoJoe19 (Joe) at Ford Bronco Zone Forums

Alsofrom batty neg to engine on pass. side; then down ...

Slow Cranking or a Grinding Noise; "... Problems with the negative battery cable is a major cause of starting problems in Ford, Lincoln, and Mercury vehicles. Bad battery cables can cause slow cranking or a grinding noise when trying to start an engine. On some late model vehicles dating back to 1994, the wire connection inside the battery terminal connector corrodes easily. This will cause a voltage drop in the cable and result in low voltage being supplied to the starter. You can check for voltage drop in the cable using a digital voltmeter. Connect the negative probe of the voltmeter to the negative battery post (not the battery terminal connector). Then connect the positive probe to the starter case and crank the engine. The voltage reading should be less than .5 volts. A higher reading means there is resistance in the cable or the battery terminal connector. Clean the cable end and the battery terminal connector and test again. If the voltage reading is still higher than .5 volts, replace the cable and the battery terminal connector..."

Source: by genco1.com

Check these fusible links;

The one from alternator to starter relay on pass. side inner fender looks like this (pic by Chris B)

Hopefully, this Link fired and save the alternator.

Fusible Link A, J & S Location Diagram, Engine Area in a 92 5.0 & 5.8

Source: by Ford via Jem270 at Supermotors.net



No Start Troubleshooting; "...First thing to check is wiring. Between the large posts of your starter relay (it's not a solenoid) should be a smaller post with a wire attached. This is the wire from your ignition switch through the park/neutral safety switch (Or clutch safety switch on a manual trans, or MLPS with an E4OD) that turns the starter over.

Check this wire for cracks, open insulation, or anything that could possibly cause an open circuit.

You could try jumping from hot to the small terminal on the starter relay to test it's operation. Sometimes new ones are bad out of the box. If it won't turn over when jumped to the small terminal, you'll know that it's a starter relay issue (Bad part, bad ground). Make sure the relay is firmly attached to the inner fender since that is it's Ground path,

If it does turns over jumped to the small terminal, then you'll be looking for something in the small circuit that includes the ignition switch & the park/neutral safety switch (NSS) Or clutch safety switch on a manual trans, or MLPS with an E4OD.

There should be 12v running from the ignition switch, thru the NSS/MLPS, to the small terminal on the starter relay.

Disconnect the small wire to the starter relay (So it doesn't start by surprise, I'd pull the coil wire too).

With someone holding the key in the start position, you should be able to read 12v between any point on that small circuit & ground. When you find where you lose 12v, then you'll know where the issue is...";

MIESK5 EDIT; changed a few terms such as changing solenoid to starter relay and deleting jumping large terminals on the relay.

I'll post this right now because my internet conn has crawled to a .... stop