It is called a "fuse" junction block but I don't see anything about it that would appear to serve the purpose of a fuse. I had a starter go bad on me. I replaced the starter and all seemed fine but now I get nothing other than a single click sound and lose power to the cab. The link I shared above mentions "Once installed all of your cars power runs through this connector. Your car will notrun c orrectly without this item."
It's not a fuse, it's a junction block mounted on the rad support. Power goes from the main splice to the junction block, From the junction block it goes to the battery via a fusible link. Charges the battery when running and supplies power to the main splice when the engine is off. The main splice is a big copper swage in the harness. Typically it has four wires running to/from it, One from the alternator, one from the voltage regulator, one to the junction block and another to the horn relay. From the horn relay power goes to the main feed through the firewall junction blocks into the cab.
I doubt that is your problem, but find it and make sure the connections are clean. Tell us a bit more about the symptoms of the first starter before you replaced it.
Sounds more like a ground problem. Charge the battery, remove and clean the battery posts and make sure they are tight when you reinstall. Remove the neg cable where it attaches to the block and clean that end then install tight. If the starter is not aligned correctly, or it it is coming loose,it the bendex could be stuck, when you try to start it the starter solenoid may not be able to pull the bendex resulting in a power draw.
Thanks for the replies! Sorry it's taken me a while to get back to you. It seems as though the issue was indeed a ground problem. I removed the neg cable from the block as you suggested, cleaned up that connection (which really didn't look bad at all) and I have power again. That seems to have done the trick however I have another issue...
To answer your question about the starter...the solenoid went bad. The starter looked like an original/refurb. I bought a Powermaster PWM-3655 from Summit. A tooth broke off the bendex on the first startup so they warrantied it and sent me another one. I don't know if it's safe to assume the starters are identical in size and dimensions but I used the same shims from the original starter I was replacing. Once I resolved the ground issue mentioned above I was able to attempt to start the vehicle with the second Powermaster starter installed. The first turn of the key turned the motor nicely. It's been sitting so it didn't fire right up as I needed to get fuel pumped to the carb. On the second and third attempts I started hearing a grinding noise. I though maybe the bendex gear wasn't spaced correctly with the flywheel so I dropped under the car to take a look. Everything appeared fine. I tried to start the car again, heard the same noise and, again checked on it and found the half-dome of metal that covers the bendex had broken into three pieces. So, at this point I'm trying to understand what the hell is going on. Did Powermaster have a bad run of starters??? I noticed the metal from the first Powermaster starter's tooth looks like cheap pot metal/white metal...whatever you want to call it. The same with the dome cap of the second starter....the metal looks cheap. What could have been the grinding noise??
Everything is so tight it's really hard to do anything more than visually check to see that the bendex gear and the flywheel are spaced correctly. I'm hesitant to get a third starter of the same model. I've already called Summit and they are going to warranty the second starter as well. That makes me very happy to hear!
Any recommendations for a good starter? It's such a pain getting the starter in and out..I have to loosen the headers at the block and further down the line on the exhaust just to get it out since it pinches against the oil pan. I think I've read about people putting the solenoid up by the battery...is that something worth considering?
I have a HI-Torque on mine, basically the same thing as yours.
They have to be indexed correctly. One installs the starter then measures how far the bendex teeth engage with the ring gear teeth and how deep the are meshed. You should have gotten some shims with the starter to adjust it correctly. If it is way out of wack the teeth could be binding and twisting the starter. Could also be high compression and the engine timing, if the timing is so far advanced it fires the plug while the piston is still way down in the hole it could stop rotation or I suppose even push the piston back down causing the crank to reverse rotate and kick-back on the starter. That would only happen at low cranking speed, the power master should be turning it pretty good.
The starter it self has to be correctly installed on the mounting block. If it is somehow kinked over at an angle it could cause a binding. These are high torque starter due to gearing, if they bind something will break.
Or the could have made a bad batch.
I have a Ford style starter relay mounted on the fender near the battery. The battery cable to the starter is only energized when the key is in the start position. That also re routes the Start wire from the key to the starter and the R wire to your distributor if you have a points ignition. A jumper is attached from the S post of the starter to the battery cable post of the starter. When the cable is energized so is the bendex and presto.
I will post pic large red cable is from battery; small red wire connected to white fusible link connects to same post as battery cable. That is from alternator and charges battery and feeds system juice when engine is not running. Blue wire is from start position at starter switch, used to connect to S on starter. Black wrapped cable goes to starter, only has power when relay is closed If I had a points distributor the wire that was attached to the R post of the starter would be attached to the same relay post the black wrapped cable is attached to..
One thing that jumped out at me was you said the starter hits the oil pan. Makes me think it's not mounted as straight as it should be. When I installed my mini it was contacting one part of the pan rail that bulges out around one of the mounting bolts. I had to hammer it back in to allow the starter to mount correctly. You might want to take some extra time and care when mounting the new one to make sure it's good before moving on.
What I meant by it hitting the oil pan is that there is not enough space between the oil pan and headers to remove the starter so I have to loosen the headers to widen the gap for the starter to be installed or uninstalled. I'll still look at it as you suggest the next time I install to ensure nothing is causing the starter to be out of alignment.
I'm gonna look into other brands of starters. I talked to a few guys who said the PowerMasters are junk and I have to agree to some extent based on the cheap metal they are using. I've also been considering having the original starter rebuilt. Is that a good option or should I stay away from doing things like that? I just need to find someone who can do it.
If it helps anyone I have the summit mini starter in my bird with a milodon oil pan which is kicked out a little and hooker super comp headers. The starter drops in and out no problems and the starter has been in the car for 5 years without any problems.
I think mine is a 108N. Your 68 400 is basically the same engine as my 68 428, except internal dimensions of stroke, bore and camshaft. It's also a pretty tight fit between the headers and the pan. One can rotate it in the mounting block to get the thing kinda centered. No room to take the cable off or on mine with it mounted so I have to attach the cable before I install the starter. Don't have to take off the headers though. If you do get one, after you know where it will be indexed on the mounting block, remove the starter to mounting block bolts and add some thread lock. Mine came loose from the mounting block a couple years ago, been tight ever since.
Wouldn't hurt to look at rebuilding your old one. Take it apart and see if it's in good shape other than the solenoid. Used to be able to buy replacement solenoids for them, don't know if that is still the case. I took one apart and just flipped the contacts over, worked great after that. The originals seemed to be affected by heat, either the starter itself or the S wire from the switch. Sometimes the starter got so hot it would drag. Sometimes the large purple start wire from the switch through the heat tube on the rear of the block, got so hot nothing would happen when you turned the key.. Most often that would be after it sat for about 10 minutes after shut down and the wires absorbed all the heat from the block and exhaust. The more heat in a wire the more resistance to current flow. The solenoid can draw 30 or so amps on initial contact of the switch. That juice has to go from the battery, all the way to the switch and back to the starter. If the wire is hot the result can be no contact of the solenoid. If you install a remote starter relay you can reduce the draw to 2 amps through the start switch. You also have no live wires running anywhere to or from the starter unless the start switch is engaged, then it's only the cable itself.
Of course I'm not an expert, these are just my opinions and observations.