Hi all, i recently bought a 1980 bronco 300 six. When i got it home as soon as i hooked the battery up, it would start cranking. So, the two little wires going to the positive side of the solenoid had corroded ends, so i replaced the ends, put it all back together and it would start fine. Now recently it would act up and the starter would stick on so i hop out and pull the battery terminal off so i dont destroy the starter. Then i kinda jiggle the wires and solednoid, hook the cable back up and it fires right up fine. So tonight, idk if my battery was dieing, or if thise finished it off but i went to start it and it slow cranked and the starter was barely turning but stuck on so i go out to pull the terminal and the positive is hot and the negative is too hot to touch at all. Im getting really frustrated with this thing as i want to daily drive it but i dont have the trust in it yet. The solenoid appears to be brand new, I cant see any shorts on the black wire going to the starter. Is it a bad starter maybe? Any help is greatly appreciated!

 

Sounds like you have several problems:

• The starter sticking on can only be one of two things - the ignition switch, not the lock but the switch, or the solenoid. 9.9 times out of 10 it is the solenoid. And, aftermarket solenoids are famous/notorious for sticking on - even right out of the box. The Ford solenoids, even ones from a salvage, are a much better bet.
• Hot wires means you are pulling too much current or you have a poor connection/wire. I'd bet on the poor connection or bad wire, and suggest you check the connections at the battery and on the engine. Further, check the battery cables where the wires go into the terminals as those are known to corrode and cause problems. If your connections and wires are good then your starter is dragging and, therefore, pulling too much current. Have it checked at the parts store.

 

Thanks for the reply. I am leaning towards the solenoid also, i think ill pick up a parts store replacement first and try it out. I realized after i pondered on it that when it would stick on the wires getting hot was probably from the current of the constant on starter, and when i would jiggle the wires, i was also jiggling the solenoid which most likely freed it. Ill pull the starter off and inspect it and have it tested for good measure. Ive already replaced the terminal end of the red cable, i guess ill also do the black for good measure once again.

 

If you go with the parts store replacement, stop by Orielly's and pick up a Motorcraft solenoid. Dont waste your time with those other solenoids. They are just too cheap. And we all know we get what we pay for. Well I have one of those parts store solenoids on the table right now in the box with the reciept waiting to be took back. I havent yet but I am going to when I remember. Since my 4x4 isnt roadworthy yet, I have a 90's 4.0 Ranger solenoid installed and it works really good. So yeah, only Motorcraft solenoids would be a good decision. I learned my lesson the hard way! So right now I have a New Ford Solenoid on the parts list, but a tad lower for right now since the Ranger solenoid is working real good. I thought about it being a tad small for the big 6 but I figured it would have to be better than the new non-Motorcraft ones!

If your ignition switch is sticking, you would have battery voltage on the small terminal wire keeping the starter being constant on. Try turning the key couple of times, with the small wire terminal removed. And then take a test light or a DVM and check to see if the test light lights up or the Meter shows 12 volts or so. IF it does then your would be on your way to finding your problem. But I doubt that is the problem. Gary's post is spot on and I would add make sure the solenoid is mounted good to the fender. The fender is the ground for the starter signal to the solenoid. Your sentence about the solenoid wobbling doesn't sound quite right, but I guess if you was jiggling the wire pretty good then i guess it would be enough to loosen it. I had to give my 3 solenoids lol non Ford part a really good TAP to break the connection. So now I have a new battery terminal that is a quick disconnect!!!!

 

The solenoid doesn't care what engine it is.

 

You are almost invariably looking at a bad solenoid! The others posts are spot on! The wiring getting hot is not necessarily a problem. Your battery cables were doing their job. That is why they are so big, so they can carry a lot of current. The heat was coming from the dead short that was created with the faulty solenoid. Under normal operation, your cables will not get hot because that electrical energy is converted efficiently into rotational energy in the starter. When there is not an efficient avenue for that current to flow, an excess of heat is built up and that is likely what you are feeling.
As for the solenoid itself, again, the guys above me are right. Stick with FoMoCo.
The stud leading to your battery that was corroded probably tracked across to the underside of the solenoid causing your initial problem(it is also important to make sure that none of the wires attached to that stud can come in contact with the underside of the solenoid for the same reason). The solenoid is a very simple spring actuated switch that when overheated from the dead short weakened the internals or left an arc track that the internals are hanging up on. Once that happens, it is toast. You can get back on the road usually by merely tapping on the solenoid with anything at hand, and that will free up the mechanism and disengage the starter but it needs to be replaced ASAP.

Lastly, the importance of good grounds cannot be overstated. If your solenoid is loose on the firewall now due to time or yanking on it to stop the chaos you were experiencing, you will need to fix this. Tighten the mounting screws. If they won't properly tighten down, you will need to either install larger hardware or drill new pilot holes for the original screws.

Hope this helps, and wasn't too rambling. Not sure if I am still making sense at 2am!

 

Man! I didnt even think that the solenoid was case grounded. Th PO stuck in on there all rigged like its loose and wobbly on the firewall. Ill remount it good tonight. I also noticed one of the hold downs thats on the black wire isnt bolted to anything so ill bolt that down. My guess would be bad ground since the isnt much good contact between the solenoid and fender. And im a lot tech at a Ford stealership so i can get a discount on solenoids!

 

What is a lot tech? Sounds like car washer/gopher.

 

Thats exactly what it is lol. I wash cars, move cars around, get salesmans lunches, help the detailer. Things of that nature

 

Yep, it's case grounded. One wire from the ignition switch, through the solenoid to ground where it bolts up.

Aproximately 80% of all Ford solenoids, switches, and devices ground through their case during this era of vehicles.

So... It was mounted on the firewall? It should be mounted on the passenger fender just above the voltage regulator. Hmmm...


If this is the negative battery ground wire going to the starter mounting bolt, that metal hold down on OEM wiring is crimped onto the bare cable with a protective sheath around it to protect the cable inside. This is how the battery grounds the frame. Then from there it connects to the starter mounting bolt. This is a quirk used to ground the frame and engine on the 300-6 of this year range. When the cable is replaced with aftermarket cables, the frame ground is usually deleted unknowingly.

The positive cable from the starter solenoid to the starter will also have a "hold down" but it's seperate and insulated from that cable.

 

And if the OP is going to be down there anyway, now is an excellent time to go ahead and replace that cable. I recently replaced the negative cable on my 1980 F-150 just for ****s and giggles (I'm a big believer in preventative electrical maintenance), and I'm glad I did; the cable was corroding inside the insulation down near the starter, and would have caused me problems before too much longer.

What I did was take some measurements from the battery down to the connection point on the frame, and then from that point to the starter. I went to NAPA and bought a regular battery cable long enough to reach the frame, and a battery cable with flat lugs on both ends long enough to reach the starter from the frame. Hooked it all up, and now I have nothing to worry about on that front.

 

Sorry i mistyped, the solenoid is mouted where it should on the fender. Now ive got it mounted tight and secure and so far no more problems. Time will tell i guess. As for the cable i spoke of, it is the black cable going to the starter, it has 2(as far as i see) metal hold downs attached to the bare cable, and 1 of the 2 wasnt hooked up. thanks for your help fellas. Next project, rebuild rear wheel cylinders!

 

Replace! They are cheap.

 

I was going to, but i figured i mine as well rebuild them(as long as they arent too pitted and nasty). I can get new ones for around $10 a piece, or rebuild kits for $3 a piece. $20 versus $6. Plus i like rebuilding things lol