I noticed today that my programmed stations on the radio were gone, indicating loss of power / reset.

Drove to town, radio kind of went in and out a couple times, weird. Thought maybe I was having reception issues.

Driving home on bumpy road - hit a bump, radio goes quiet, rear antilock brake warning light comes on, and rpm needle pulses lower then back to normal.

This happened several times, and on one harder bump I swear the engine rpms actually dropped noticeably, as in loss of power. The other times I thought the needle dropped but the motor stayed steady.

Electrical short somewhere, wire rubbing through, or loose ground?

With those symptoms where should I start checking?

 

Check your battery terminals and grounds. You might hve them corroded to the point that it's losing connection at certain bumps.

 

Batteries, battery cable including crossover, starter, and starter solenoid all less than three years old. I updated the whole starting system.

Battery terminals tight and no corrosion except a little on passenger positive.

 

Tried to start this morning, turn key, NOTHING. No lights, no horn, no wipers, no interior lights, nothing.

I think the power supply to the ignition has come loose or broken, or ignition switch went bad? Maybe a fusible link?

I have power at the starter solenoid, batteries reading 12.5v, so they're not dead.

Anyone know the wire color that powers the ignition? I've got a Chilton manual but it conveniently doesn't have a complete starting system diagram, in fact no engine diagram for a diesel at all.

 

Been doing more reading, found this video:


Thought the actuator would be it, took the lower cover off to test and it's working fine. But when I turned the key the chime came on, so I think this intermittent problem may let me start the truck. If it does it's going straight to the shop so I can avoid a potential tow bill.

 

I keep updating this, mostly so anyone in the future can learn from my problems.

I'd love some feedback from somebody who's BTDT....

So the truck chimed two different times when key was inserted, think it would have started. BUT, I didn't have a ride back from the shop lined up and by the time I did it wouldn't do anything.

So, I pulled the dash cover and instrument panel.

How to take out the instrument panel out on an 89 F250:

The light and washer **** have a spring steel clip retainer holding them on. An allen wrench or other curved tool will release the spring pressure and the ***** come off.

The left bottom side of the dash panel comes off first, then the right bottom panel, unhooking electrical as you go.

The instrument panel has electrical hookups on left and right and speedometer cable in the center. It's a tight fit to get your hand back there.

To remove the speedometer cable push up and twist around on the white round tab. Work at it for a minute and it'll pull out.

My goal was to reach the ignition switch. I still can't, and I think pulling the panels was a waste of time. What I should have done was take loose the U clamp holding the steering column in and dropped the column down so I can reach the top of it.

On an automatic there's supposed to be something you can damage doing this, but I've got a manual.

From my reading there will probably be one or two yellow wires around the ignition switch that are constant hot. If that's the case I'll replace the switch, because power obviously isn't getting past it.

If power isn't getting to the switch I know I've got a break or short somewhere between there and the starter solenoid.

While I've got all this crap apart I intend to replace all the instrument panel bulbs (they're 28 years old and right there!), I'll probably replace the ignition switch whether it's good or bad, and I intend to fix the warning chime which has gone very quiet. I've left the lights on a time or two because of this.

 

with the lower dash panels off, loosen or remove the nuts that hold the column up.
this will allow the steering wheel to drop down to the seat.
look down the top of the column, and you will see the ignition switch.
check it closely to see if it is separated. what happens is the switch will split apart where the plastic piece goes into the aluminum piece.

another thing to do:
trans in neutral, parking brake set. turn key to run. go under hood ad jump the starter relay. see if it will start.

 

I dropped the column, the plug into the ignition switch seems fine, but missing an ear so someone has been into it at some point.

I have no power to the plug on any of the wires. From what I've read on other models the two yellow wires are the constant on / power supply? I read on the pins in the plug and stuck a straight pin into the wires and grounded to the door hinge, couldn't get anything.

So, I'm guessing a wire is broken somewhere between there and the starter relay.

Problem is that's a long way in bad tight spaces, and I don't have a wiring diagram for this truck.

Any ideas on how or where to start looking? I'm not great with electrical, so if there is a continuity test or something to narrow the search I don't know how to do it.

I'd also like to replace the plug to the ignition switch. Would a common parts store have that?

 

ok. look closely at the wires coming off the starter relay on the fender.
on the battery side lug, there should be two or three wires around 10 gauge. those are fusible links. inspect them closely for damage or burn marks. one is for ignition, the other is for charging system.
the may also be one for the glow plug system.

 

Loose nut on the starter relay. I had checked power several times at the relay, but I hadn't stuck a pin in the other wires coming off to make sure it was getting through to them.

I went to take the battery lead off the relay to start tracking the short down and thought "Dang, this nut is loose..." Yep, tightened it and opened the door and the cab light came on.

I'm still going to replace the ignition switch and probably the plug too while I'm in there, as well as put a headlight warning buzzer in. Waiting on parts to arrive before I get her put back together.

Always the simple stuff.

 

well, better a simple head scratcher than a hard replace the complete engine bay wiring harness!!!

 

Parts came in so I repinned the ignition socket and replaced it, swapped out the ignition switch, and yanked the old way too quiet door chime.

Everything works like a champ now.

On the door chime - I replaced it with a headlight warning buzzer I got from LMC. It's supposed to parasite into the fuse panel but I couldn't get it to work, so I plugged it directly into the plug for the now removed door chime. It took some fiddling to figure out the wire positions, but now the buzzer ONLY comes on if the key is off and the headlights are on. No door warning at all, only headlights. And it is LOUD.