Got a '69 351W. Was putting it all back together after installing intake and carb this weekend, hooked it all back up according to the tape on the wires and the pics I took prior to disassembly... on the third attempt to turn it over, the starter relay started smoking and it wouldn't quit turning over when I switched the ignition switch to off. Disconnected the negative cable on the battery.

Replaced the solenoid, and when I reconnected the negative, it started to turn over, even with the ignition switch OFF. I even tried disconnecting the little wires that go to the starter relay, and it still turned over when connecting the neg cable on the battery.

Does a starter relay get 'stuck' closed, keep in mind, this was a newrelay that did the same thing as the old one. If I put a continuity light on the starter side of the relay, should I get a light if the ignition switch is off or disconnected? I used the neg term on the battery as the ground.

 

Time for a new relay.

 

+1

Unless there is something I'm missing, the wiring to the solenoid won't cause what you're seeing. Possibly a bad ignition switch...

If you disconnect the starter lead, at the starter, andreconnect the wiring at the solenoid... then attach your test light ground to the negative terminal of the battery, you should not get a light on the starter lead at the solenoid. If you do, then disconnect the ignition switch, and check it again.

Please let us know what you see from there!

 

From what you are saying, it is my opinion that both solenoids are defective, if

1. The battery is attached to one side of the solenoid, and the starter is attached to the other side.

2. The starter turns the motor over when BOTH small wires are disconected from the solenoid.

3. There is not a wire from the battery side of the solenoid going to one of the small terminals on the solenoid.

It would be a coincidence, but it is possible. Is the old solenoid really old or did you recently change it as well? (since the motor has been started) If they were both "new" then the parts store might have gotten a bad batch.

 

I assume it didn't do this BEFORE you disconnected everything. If that is indeed the case you have most likely wired something wrong. Get a wiring diagram!! I cannot emphasize this enough. Do not ever disconnect wire without the proper schematic at hand. I cannot count the times I've seen guys work on wiring on cars, motorcycles, stereos etc. and not be able to get it right all because they reversed something, grounded the wrong lead, or had the wrong wire going to the 'hot' side.
My experence tells me the probability of the rely going bad at the exact moment you did your work is very low. THEN you add the probability of the 2nd rely doing the same thing.....well...let's just say you have a greater chance of winning the lottery 2 week in a row.

 

Thanks. This weekend I'll give those suggestions a shot. I suspect that I might have developed a bad ignition switch, the key was clicking differently than normal. No idea how old the original relay is, it was on the car when I got it. I'll be pulling out the ol' wiring diagram. mikethebike has a point, but I was very careful to replace wires as disconnected (labeled wires, etc). What's the difference between pulling the starter lead at the starter vs at the solenoid?

 

If all of the small wires are disconected from the soleniod, the ignition switch will have nothing to do with the starter cranking. If I have read your posts corectly, you have stated that the starter was turning over even though all of the small wires were disconected. If this is true, then it is my opinion that the solenoid must be stuck.

Your ignition switch might be bad, but if I have read everythig correctly, it is not the problem with the starter cranking on it's own, if the small wires are disconected from both center terminals, the ignition switch is not even part of the circuit.

The solenoid is nothing more than a relay SWITCH, it can not be switched on if the small wires are not connected.

The only purpose of the solenoid is to complete the high amperage circut between the battery and the starter, (big wires on solenoid)by using a low current signal from the start circuit of the ignition switch (small wires on solenoid).

Your starter might be drawing too many amps, (due to new tight engine, low voltage of battery,or a defecive starter. If this is the case the additional amps, may be effectivly "welding" the plunger in the solenoid to the contacts, thereby destroying them.

I recomend replacing the solenoid again before playing with the ignition circuit, and replacing it with a good high quality replacemrnt, not an AutoZone or NAPA special, get a OEM replacement from Motorcraft.

 

Thx JMD. True on the little wires not being on the solenoid. I'll try one more solenoid. I can afford $20. I'll do the tests from bronco1, too. Wish I could get to it sooner than this weekend!

 

Sorry, I was edditing my last post while you were replying to it, you might want to look at it again.

Also I wanted to say that when you replace the solenoid, hook up all of the wires that go to the big cables first, and then carefully touch the negative terminal to the battery, the starter should do nothing.

If indeed the starter does nothing, hook up the negative cable to the battery, and then carefully attach the small wires to the solenoid. If the starter still does nothing your problem might be solved. if the starter does begin turning when you touch the small wires to the solenoid, then you have somthing crossed, or the ignition switch is bad.

By following these procedures with a new solenoid, you can troubleshoot at the same time, thereby narrowing down where you need to search for your (possible)problem.

If with the new solenoid, the starter begins turning upon just hooking up the wires to the big posts, then I have flunked electrical, and I will need to re-educate myself on this circuit, but ther is no way!!
Good Luck!!

 

Well, it appears that I had three problems. I disconnected the starter. I was getting current through the relay with only the battery connected. I replaced the starter relay. I was still gettingcurrent thru the circuit when the ignition wires were connected. So I replaced the ignition switch, and the problem went away. Then I connected the starter, got current again. So I replaced the starter (which was a job because of long tube headers and rack and pinion). Problem solved. Started it up, and proceeded to crap the fuel pump... fuel spraying all over. That's another day, though! I guess the faulty ignition switch caused the starter relay to 'weld' itself closed, or the faulty starter stayed closed, thus frying my relay and ignition switch. Not sure if it could affect my ignition switch, but it's fixed... for now...