Greetings,

I Have a 1989 F-150 Lariat and it has a problem with starting.....

Occasionally now when I go out to start it up in park it won't turn over and if I move it to neutral it does. Sometimes just moving it to neutral and back and it would start.....This may be tied into the problem that I am about to describe

Now last nite I was driving home form work the lights actually went out and came back on (Of course this happens in a driving rain storm and in rush hour traffic on the freeway) naturally...the battery gauge was bottomed out...

All of a sudden the lights came back on and the battery gauge showed that the battery was charging, so I figured it was a loose connection at the battery...

Now I cleaned terminals and tightened the connections and have lights etc but the engine will not turn over. There is power to the solenoid and power to the starter, it is trying to turn over the engine but no go.....

Any ideas as to what this is and why The issue with the first problem...Are they related????

 

The no-start is probably cause by the MLPS (E4OD trans) or NDS (AOD). The original MLPS, in particular, is noted for being unreliable. Ford eventually made significant changes to the design to deal with this issue.

The no-start is almost certainly not related to the lights going black.

If the voltmeter dropped all the way to the bottom of the scale, you probably have a fairly severe short circuit in one of the high current, non-fused wires. This may have been further "enhanced" by enough water getting into some part of the wiring with damaged insulation. A loose battery connection will not cause the voltage to drop to zero -- the alternator should hold the voltage up enough to not get "black dark" from the lighting system.

The battery may have been discharged or even damaged by the short. That may be why there is not enough voltage/current to start the truck. Try a good set of jumper cables (not some cheesy 10AWG Made-in-China sold-by-Walmart items) to another vehicle with a good battery. Try jumping to the battery and also try taking the positive lead over to the input side of the starter solenoid.

 

Greetings,

Thank you very much Fefarms for the advice and it helped with the troubleshooting...

I forgot to mention that my truck has A/C which might make a difference

Well I replaced the solenoid and positive battery terminal wire (between Solenoid and Battery) and probed with my multimeter and got readings of 12.4 V in and 12.4 V out of Solenoid and 10.4 V out at power lead (Top of solenoid) to ignition switch...So power coming out of battery to solenoid to starter, and I was told anyway that Ignition switch and starter relay are working...so either ground or starter...turn over key Truck Starts....Idle for a while....Turn off key truck won't start...examined ground and replaced negative terminal and truck still won't start....Crawled under and knew it was the starter(You could smell the burnt insulation)....so replaced the starter, one problem the starter was only a couple of months old....ANd before that replaced it last year and the year before this....If you let the truck sit for awhile say a week the battery is dead....So open circuit someplace..

So I looked at there appears to be only one wire from solenoid to starter, so what could fry this starter...The manager at local schucks suggested that it was the battery ground was bad, since I replaced this is the problem fixed?? Or is it the sign of something more serious?????

He said that the issue with the truck having to be in neutral has to do with a Park/Neutral position switch.....I assume that this has to be replaced but where is it and how to do it???(CHilton is worthless for this piece)....Could this be tied into the starter motor meltdown.....

Also noticed that the AM on the radio quit working along with Clock but the FM still works, so I assume that this is tied into the power surge that may have fried the starter??????

What is the fuse type connector linkage that is right below the solenoid, if you take it apart it looks like there is a thick wire that goes into the other section of it (Has a milky white substance on it)? Is this supposed to be a bus fuse or is this a fusible linkage that chilton talks about but shows no pictures...

Thank you for any advice

Dennis

 

A voltage surge will not damage a starter, for several reasons. The starter is not connected to the electrical system unless the solenoid is energized. The starter windings are thermally robust and electrically low resistance, so it can easily take anything the alternator can dish out.

Staters do get damaged when the bendix assembly sticks, and the starter gear fails to disengage from the flexplate. The starter gets spun really, really fast by the engine and centrifugal force damages the windings.

Another bad thing is for the solenoid to stick and leave the starter motor running. It is not meant for continuous duty and 3 to 5 minutes of operating will overheat it and burn the windings.

If the starter engages, but will not turn, or turns very, very slowly, and you hold the key in "start" for more than 10 seconds or so, you can overheat the starter due to the lack of back EMF.

If you are getting 12.4 volts out of a battery, or the input or output of a starter solenoid, with the key in "start", then the starter is not drawing the amount of current that it should. Internal battery resistance should result in a voltage drop when the 100+amps of current flows to the starter motor. Reasons for low current could include high resistance power or ground connections, or a damaged starter.

The best way to truly fix the battery ground is to put on two new cables. Run one from the battery post to the bolt on the frame. Run another from the frame to the block. Thoroughly clean up to bare shiny metal the areas under the bolts. Bolt on replacement clamps tend to oxidize between the clamp and the cable. The OEM Ford pne-piece design, with the middle ground clamp against the frame, does not make an especially relaible connection to the frame.

The MLPS on an E40D bolts to the lower left side of the transmission, about halfway back. The neutral safety switch on an AOD is inside the trans. Not sure which trans you have.

If the truck drains the battery while it is parked, you have a short circuit or a switch which is not opening when it should. Not an "open circuit". To diagnose, get an ohmmeter or digital multimeter. Disconnect the hood lamp. Shut the truck off and make sure nothing is turned on. Disconnect the battery ground strap. Loosen the nut holding wires connected to the battery side of the starter solenoid. Now determine which of the 5 or six wires normally bolted to the battery positive at the solenoid has a "low" resistance, using the ohmeter between the wire and the battery ground cable (not the battery post, remember that you disconnected the battery ground) . It is acceptable for one or more of them to show a value perhaps as low as 10000 ohms. This could be a source of standby current to the PCM or the clock, etc. But lower resistance than that is too high a load, and will drain your battery. Once you find the offending wire, you will need a circuit diagram to figure out what circuits that wire drives. Using the circuit diagram, you can start removing the fuses associated with that wire to further narrow down which portion of the hanress has the short..

The fusible links are in the harness, right after the connection to the starter solenoid post. To my knowledge, there are no inline replaceable glass fuses at this point. It is possible your vehicle has some add-on gadget that somebody connected there.

A sudden electrical surge due to (for example) loss of battery ground could fry various electronic components in the radio. But this is unlikely to be related to issues with the starter.