1997 F-250 Ignition Problem

"Joe" wrote: 1997 F-250 Ignition Problem

My ignition switch has always been touchy: If you turned the key all the way it would not start. If you snuck up on it slowly it would start. If you went past a magic point then backed off it would start.

Now my truck won't start at all. I don't see anything wrong with the ignition switch. Substituting a switch from my Explorer did not help.

Any ideas on where to look next? Could I hot wire it? ______________________________________________

Does "my truck won't start" mean:

Absolutely nothing happens? It cranks but doesn't fire? Something else?

A description of what happens will help someone suggest a solution.

Good luck.

Rodan.

Sorry the problem is in the cranking over, so now I can't find any spot where it will crank over Thanks Joe

"Joe" wrote: 1997 F-250 Ignition Problem

My ignition switch has always been touchy: If you turned the key all the way it would not start. If you snuck up on it slowly it would start. If you went past a magic point then backed off it would start.

Now absolutely nothing happens when I turn the key. I don't see anything wrong with the ignition switch. Substituting a switch from my Explorer did not help. Any ideas on where to look next? Could I hot wire it? _________________________________________________

It sounds exactly like a defective switch.

But you say a known good switch does not help. The next most probable cause is an intermittent electrical connection somewhere. Some things to try:

1.) Turn the key while wiggling the gear shift lever. This may detect a bad transmission interlock switch.

2.) Turn the key while wiggling the wires near the switch cable. This may detect a broken relay energize wire.

3.) Touch a jumper wire from the 12V battery terminal to the energize terminal on the starter relay. If the starter turns this will confirm that the starter is not the problem. If nothing happens, it could be a bad relay, a bad starter, or bad battery cable connections.

4.) With a voltmeter, read the voltage at the energize terminal on the starter relay while turning the key. This will confirm whether voltage is reaching the relay.

5.) Disconnect the energize wire from the starter relay. Examine it for a bad terminal crimp (corrosion, soot) and for a broken wire inside the insulation (soft loose area). Clean the wire and solenoid terminals and reinstall. Try the key.

6.) Disconnect the switch cable [NOTE-some of the wires are always hot]. Examine its starter energize wire for a bad terminal crimp and for a broken wire inside the insulation. Clean the terminal and reinstall. Try the key.

7.) Take the switch out and operate it manually while reading an ohmmeter between the switch's 12V battery input terminal and the starter relay energize terminal. This will confirm if the switch is okay.

8.) Try another known good switch.

You can rig up a temporary jumper by running a wire from the battery 12V terminal, to a push-button switch on the dash, to the energize terminal on the starter relay. To start the engine, turn the key to the run position and push the button.

Try these things and post the results, with details about each result (sounds, smells, looks). If these don't work there are plenty of further things to try.

Good luck.

Rodan.

Sorry for the top post.

"Joe" posted this same problem in alt.trucks.ford, insisting the ignition switch was not the cause, but later admitting there that he had never checked the switch.

He didn't update alt.autos.ford regarding his mistake so a lot of time and effort was wasted here trying to help him.

It's discouraging.

Rodan.

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"Joe" wrote: 1997 F-250 Ignition Problem

My ignition switch has always been touchy: If you turned the key all the way it would not start. If you snuck up on it slowly it would start. If you went past a magic point then backed off it would start.

Now absolutely nothing happens when I turn the key. I don't see anything wrong with the ignition switch. Substituting a switch from my Explorer did not help. Any ideas on where to look next? Could I hot wire it? _________________________________________________

It sounds exactly like a defective switch.

But you say a known good switch does not help. The next most probable cause is an intermittent electrical connection somewhere. Some things to try:

1.) Turn the key while wiggling the gear shift lever. This may detect a bad transmission interlock switch.

2.) Turn the key while wiggling the wires near the switch cable. This may detect a broken relay energize wire.

3.) Touch a jumper wire from the 12V battery terminal to the energize terminal on the starter relay. If the starter turns this will confirm that the starter is not the problem. If nothing happens, it could be a bad relay, a bad starter, or bad battery cable connections.

4.) With a voltmeter, read the voltage at the energize terminal on the starter relay while turning the key. This will confirm whether voltage is reaching the relay.

5.) Disconnect the energize wire from the starter relay. Examine it for a bad terminal crimp (corrosion, soot) and for a broken wire inside the insulation (soft loose area). Clean the wire and solenoid terminals and reinstall. Try the key.

6.) Disconnect the switch cable [NOTE-some of the wires are always hot]. Examine its starter energize wire for a bad terminal crimp and for a broken wire inside the insulation. Clean the terminal and reinstall. Try the key.

7.) Take the switch out and operate it manually while reading an ohmmeter between the switch's 12V battery input terminal and the starter relay energize terminal. This will confirm if the switch is okay.

8.) Try another known good switch.

You can rig up a temporary jumper by running a wire from the battery 12V terminal, to a push-button switch on the dash, to the energize terminal on the starter relay. To start the engine, turn the key to the run position and push the button.

Try these things and post the results, with details about each result (sounds, smells, looks). If these don't work there are plenty of further things to try.

Good luck.

Rodan.

You don't say which engine but, I am assuming a gasser. If so, check the ignition wire connection to the starter solenoid on the starter. They sometime corrode giving your symptoms.

Lugnut

Snip Thanks for your response I have put in a new ignition switch (the electrical part not the key part) but did not fix the problem. I have pulled the starter motor and confirmed that it is good (took it to pep boys and had them check it) but after re installing it still no luck. I have given up for tonight, so tomorrow I will try the other things you suggested I did try moving the gear shift leaver while trying to start it also tried manually working the ignition switch, still no crank. Is there a relay to check I can hear a relay click when I try to start it but don't know where it is? Also do you know what the gray wire with the yellow strip is who ever owned this be for me has a jumper wire going from the large gauge Gray/Yellow to a lighter gauge Gray/Yellow both are in the wires going to the ignition switch? Thank You Again Joe

351 cid Automatic

"Joe" wrote: 1997 F-250 Ignition Problem 351 CID A/T

I replaced the ignition switch but it did not fix the problem. Pep Boys checked the starter and it is good. I tried moving the gear shift lever while trying to start - no help. I tried manually working the ignition switch, still no crank.

The previous owner has a jumper wire going from the large gauge Gray/Yellow to a lighter gauge Gray/Yellow. Both are in the wires going to the ignition switch. Do you know what the gray wire with the yellow stripe is?

I can hear a relay click when I try to start it but don't know where it is. Is there a relay to check? _________________________________________________

1.) Sorry, no knowledge about the gray/yellow wire.

2.) If a relay clicks when you turn the key to the start position it is probably the starter solenoid, which is a relay. If so, that's good news. It means the switch and the wiring are working, bringing the start energize signal all the way to the solenoid. That leaves the battery, the solenoid, the cable connections and the starter to check. And you already checked the starter.

Good luck.

Rodan.

If yours is wired the way I think it is, it will have 2 starter solenoids. One on the fender near the battery and one on the starter. I have had a couple of problems with mine. One is the wire to the starter that I mentioned before. The other was a bad solenoid on the fender. IIRC, it has a diode in it that went bad losing connection in the solenoid. Can you check to see if you are getting voltage to either the battery cable or ignition wire at the starter when you turn the switch to start? Keep in mind that it has several fusible links in the wire harness under the hood. One of the big problems is tracking where you are losing power.

Sorry I can't be more help at the moment

Lugnut

By "switch your tried" do you mean the part that the key goes in? If so, look to the top of the column under the dash.

Well I am stumped, I guess Saturday when I have some day light I will try to trace some wires. Tonight I changed the fender mounted solenoid / relay still no crank, so I jumped the terminals and it turned over, so I ran a wire from the solenoid to the dash so I can at least start it which it does now but there has to be a way to find the problem. I did not get to check every thing with the meter yet (gets dark to quick now) but that will be Saturdays project. Thanks Joe

"Joe" wrote in news:4EN6h.2972$%U.1171@trndny07:

you need to find your neutral safety switch and check it. KB

"Rodan" wrote in news:4V96h.2137$%U.1880 @trndny07:

install a jumper cable. "U" shaped heavy guage wire with (I think) a female spade connector at each end. Attach this jumper wire to both connectors on the tranny. Then use caution as the vehicle will start in any gear.

jfk

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