Why won't my Bronco start?

[B-150 Mudder]

I have a 86 Bronco with a 302, I have been having the issue of it starting on some days and not starting either later that day or the next day. If you let it sit for a couple of days it will sometimes start. It seems to only fire right up when I don't want to drive it...isn't that how it always works! I have replaced the ignition switch on the column and still nothing, then I took a wire brush to my starter ground and the ground on the frame on the passenger's side of the engine. I am lost and have no idea were else to go with the problem. Please Help! Thanks.

 

[BroncoJoe19]

You may want to try an exorcist.

Please explain your problem a little more clearly so that we can help.

Does the engine crank when you turn the key?

Does it crank as fast as you think that it should?

How old is the battery?

When was it last turned up?

DO you have a carbureted system, or is it EFI?

Stuff like that.

joe

 

[maddogv21]

I had a similar problem with my 66 Chevy C-10. Check the starter soleniod. Mine was bad so I just replaced the whole starter and never had the problem again. Im not exactly sure how to test the soleniod on the starter but Im sure if you took it to autozone, they would test it for free too. Hope this helps and let me know how that works out for you.......

 

[B-150 Mudder]

It is EFI and no it doesn't even crank over when you turn the key. It will start if I jump the seonoid with a screwdriver. When you turn the key there is nothing there no click, or anything. I gave the engine a tune up with new plugs, wires, ignition control module, coil, and air filter when I purchased the truck which was about a year ago. I even tried to switch out the selonoid and that didn't help. The battery is about 3 yrs. old, I do however think that the alternator went out on me the other night. I was driving it and it just died, then it wouldn't start at all, the voltmeter was only reading 10 when I turned the key on after it died. I hope this is more clear and helps in the quest to fix it. Thanks.

 

[Seabronc]

If it will start when you jump the solinoid with a screwdriver, then you can eliminate the battery. Have you tried applying 12V from the battery to the small terminal on the solenoid that the red with blue stripe wire is connected to? If that works, then you are down to the wire from that terminal to the key switch. More than likely it is a problem with the neutral safety switch on your transmission next to the shift linkage, either loose or corroded connection.

Good luck'

>-

The circuit

 

[BroncoJoe19]

I am starting to think (and am liking it) that Seabronc and I are a team... I ask questions and he gives answers. He REALLY knows a LOT more about this stuff than I.

So... yeah.. like he said.

If OTOH your Bronc will start on warm days, but not cold days, it may be your battery. At three years old it is most likely near the end of its life span. You can get it checked where they can put a load on it and see how well it holds voltage.

Please let us know how you make out.

joe

 

[Redneck86]

Dude i know exactly what it is, the starter switch is bad i have an 86 bronco that did it and i had to start it the same way with a ***** driver. you have to replace that red wire that you take off to jump it with the ***** driver

 

[Broncobill78]

Work the problem one step at a time. First off, you say it isn't starting but is it CRANKING ? If it's turning over just fine but simply not firing that's one thing but if it's not doing *anything* when you turn the key that's something completely different. If it's cranking & not starting then it's probably a fuel or spark issue, if it isn't cranking at all it's most likely an electrical issue. If it's not cranking at all the follow Fred's advise and start eliminating suspects by trying to jump the solenoid. If you can start it with a screwdriver across the solenoid then as he said it's very likely the neutral-safety switch, if it *won't* start when jumping the solenoid then replace the solenoid & see how/if it starts.

 

[Seabronc]

Work the problem one step at a time. First off, you say it isn't starting but is it CRANKING ? If it's turning over just fine but simply not firing that's one thing but if it's not doing *anything* when you turn the key that's something completely different. If it's cranking & not starting then it's probably a fuel or spark issue, if it isn't cranking at all it's most likely an electrical issue. If it's not cranking at all the follow Fred's advise and start eliminating suspects by trying to jump the solenoid. If you can start it with a screwdriver across the solenoid then as he said it's very likely the neutral-safety switch, if it *won't* start when jumping the solenoid then replace the solenoid & see how/if it starts.

Yah, duh I forgot the solinoid posibility :blush:

>-

 

[BroncoJoe19]

Hi Guys,

He already switched out the ignition switch and the solinoid. It cranks when he jumps the solinoid, so that means to me that he is not getting power to the low amperage side of the solinoid (the little wires when he turns the key).

I am guessing that the neutral safety switch is in that loop, and is the next thing to check. IS there a way to jump that out?, or at least to check to see if is getting voltage to both sides of it?

joe

 

[B-150 Mudder]

You guys are helping me out HUGE! I only get to check this post on days I am at work so that is why I haven't put anything else in, but I will try the starter switch and the nuetral safety switch I can't believe that I didn't try the nuetral safety switch I had the same problem on a buddy's 80 F-150 and we had to loop the system to get it to work. I will let you know what happens with it. Thanks again for all of the great information. /

 

[bidibronco]

I'm a dummy and I don't know the location of the NSS? I'm sorry, I'm a bit on the slow side sometimes...

 

[Jersey]

I'm a dummy and I don't know the location of the NSS? I'm sorry, I'm a bit on the slow side sometimes...

LOL. Its either where the shift linkage goes into the trans, or attached to the shaft on the opposite side of the trans. Depends on the vehicle. More coffee? lol

 

[B-150 Mudder]

Dude i know exactly what it is, the starter switch is bad i have an 86 bronco that did it and i had to start it the same way with a ***** driver. you have to replace that red wire that you take off to jump it with the ***** driver

When you replaced yours did you test the problem before you replaced it. If so how can I test it before tearing the entire wiring harness apart back to steering column? Does the wire run into the ignition switch that is on the top of the steering column? Or does it run into the actual key switch? Thanks.

 

[Sarahs85Bronco]

]

 

[BroncoJoe19]

From the Haynes manual

For the C-series, and E4OD transmissions

1. raise the vehicle and support securly on jack stands

2. locate the Park/Neutral position switch on the drivers side of the trans, and disconnect the electrical connector.

3. Locate the two R/L or W/PK and R/LB colored wire pins in the connector and check for voltage at one pin while holding the key in the START position. If no voltage is indicated at either pin, repair the harness to the ignition switch START circuit and check the starter for operation.

4. IF voltage is indicated, jumper between the pins and check for voltage at the starter relay S wire while holding the key in the START position. If voltage is now indicated, replace the switch and adjust it.

For AOD transmissions

1. raise the vehicle and support securely on jack stands

2. locate the switch on the drivers side of the trans, and disconnect the electrical connector.

3. check for voltage at one pin while holding the key in the START position. If no voltage is indecated at either pin, repait the harness to the ignition switch STart circuit and check the starter fo operation.

4. IF voltage is indicated, jumper between the pins and check for voltage at the starter relay S wire while holding the key in the START position. If voltage is now indicated, replace the switch.