1981 F250 electrical problem
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Mountain Pass
Joined: Jul 2014
Posts: 102
Likes: 2
1981 F250 electrical problem
I can't figure this out. Truck started fine when I went to the store. When I went to leave it wouldn't start. I didn't hear the solenoid click. No headlights or hazard lights.
Attempting to jump start resulted in one click from the solenoid. Nothing after the first attempt.
I replaced the battery. I got lights and hazards working. When I try to start it they stop working. After a while they would work again but still no start.
I took a resistance reading from the battery to chassis and to the solenoid. Chassis was fine but I wasn't getting a reading on positive to solenoid. I cleaned the connections and now I'm reading between 1 and 3 Ohms.
Is the part near the solenoid labeled "Short Circuit Protection" a self resetting breaker? That would explain the loss of power after attempting to start and it coming back.
Currently I have no power to anything like lights or hazards. When turning the ignition there is no voltage on the wire at the solenoid when measured to negative. When I jump the solenoid the starter cranks but I have no ignition.
I appreciate any help . Thanks.
Attempting to jump start resulted in one click from the solenoid. Nothing after the first attempt.
I replaced the battery. I got lights and hazards working. When I try to start it they stop working. After a while they would work again but still no start.
I took a resistance reading from the battery to chassis and to the solenoid. Chassis was fine but I wasn't getting a reading on positive to solenoid. I cleaned the connections and now I'm reading between 1 and 3 Ohms.
Is the part near the solenoid labeled "Short Circuit Protection" a self resetting breaker? That would explain the loss of power after attempting to start and it coming back.
Currently I have no power to anything like lights or hazards. When turning the ignition there is no voltage on the wire at the solenoid when measured to negative. When I jump the solenoid the starter cranks but I have no ignition.
I appreciate any help . Thanks.
FTE Legend
Joined: Nov 2015
Posts: 30,981
Likes: 4,134
From: Angier, NC
This was made just for you, read it 2 times then do the checking. https://www.ford-trucks.com/forums/1...w-starter.html
First can you post a picture of the battery and the solenoid and this thing you call "Short Circuit Protection"?
Also forget the ohm meter use a volt meter or even easier a 12 volt test light as you are checking for power not so much volts if that make sense?
Once we see what you got going on we can guide you what to do if you dont find it with the voltage drop test.
Dave ----
First can you post a picture of the battery and the solenoid and this thing you call "Short Circuit Protection"?
Also forget the ohm meter use a volt meter or even easier a 12 volt test light as you are checking for power not so much volts if that make sense?
Once we see what you got going on we can guide you what to do if you dont find it with the voltage drop test.
Dave ----
FTE Legend
Joined: Nov 2015
Posts: 30,981
Likes: 4,134
From: Angier, NC
I would start by cleaning both battery connections. They make a tool just for cleaning the post & the cable ends and they are not a lot of money.
I would also remove the cables & wires to the solenoid and clean then good using a wire brush or sandpaper.
Also remove the solenoid and clean where it bolts to as the solenoid needs to be grounded to work.
Also you will want to check other grounds on the truck.
I dont know what motor you have but from the battery it should go to the top of the frame rail and if v8 to the motor, 300 six to the top starter bolt.
There is also a 10 ga. wire from the motor to the firewall. The 300 is from the left side of the block as there is a threaded boss, then up to the firewall by the throttle cable.
V8 might be from the back of the head or intake manifold to the firewall by the throttle cable.
See what that does
Dave ----
I would also remove the cables & wires to the solenoid and clean then good using a wire brush or sandpaper.
Also remove the solenoid and clean where it bolts to as the solenoid needs to be grounded to work.
Also you will want to check other grounds on the truck.
I dont know what motor you have but from the battery it should go to the top of the frame rail and if v8 to the motor, 300 six to the top starter bolt.
There is also a 10 ga. wire from the motor to the firewall. The 300 is from the left side of the block as there is a threaded boss, then up to the firewall by the throttle cable.
V8 might be from the back of the head or intake manifold to the firewall by the throttle cable.
See what that does
Dave ----
Lead Driver
Joined: Jun 2013
Posts: 5,691
Likes: 1,173
From: Tolland, CT
The ground cable is just in case you need one.
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Lead Driver
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Thread Starter
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Mountain Pass
Joined: Jul 2014
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I'm thinking I'm not getting power into the truck. I'm going to trace wires this afternoon.
Thanks for the link. I'll check it out.
Lead Driver
Joined: Jun 2013
Posts: 5,691
Likes: 1,173
From: Tolland, CT
"turning over" is one thing, starting up is another.
"turning over" means the starter is spinning the crankshaft.
If the disturbitor is not sending spark to the plugs, that's another issue. Check for power to the coil with the key in "run"
Are you sure your getting fuel flow into the cylinders ?
The, Dave's are much better at this stuff then me. I'm a hands on guy, it makes more sense to me then.
Thread Starter
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Mountain Pass
Joined: Jul 2014
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Fuel is flowing. I have a clear filter and can see it.
I haven't checked for power to the HEI distributor. I'm pretty sure there is none. I will test with a meter.
FTE Legend
Joined: Nov 2015
Posts: 30,981
Likes: 4,134
From: Angier, NC
When you say no power into the truck when you turn the key on do you get any dash lights?
If no lights we need to look at something else but if you hav lights but will not crank with the key we need to look else where.
Dave ----
Lead Driver
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Did you use a pair of screwdrivers to momentarily connect the two large terminals on the starter relay?
Or did you connect directly from the battery’s (+) post to the heavy cable leading directly to the starter? That would bypass the short heavy cable.
Or do you mean you connected battery power to the small S terminal on the starter relay? That would mimic the normal start command via the ignition switch.
We're not trying to bust your behind with all these questions. We’re trying to understand the exact situation, as the troubleshooting path is different for each one.
Did you work through the troubleshooting guide linked in post #2 above? What an amazing guide! Who wrote that? Not only is he brilliant, I bet he smells nice, too.
One possibility is a marginal connection within one of the cables at the battery. If bumped just right, the connection can’t handle the current. But move the cable slightly and things change. The suggested test will help isolate that.
Last edited by kr98664; Mar 1, 2026 at 03:12 PM.
Thread Starter
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Mountain Pass
Joined: Jul 2014
Posts: 102
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I decided to start from the beginning. I didn't have anything at the voltage regulator so I cut open this rubber splice that connects the voltage regulator to the wire you mentioned. I don't know if you can tell from the picture but that wire is cooked. And that's after cutting it from the splice and stripping it back.
Thank you so much to everyone who helped!