Electrical Gremlins

[69PaleHorse]

This afternoon I ran a few errands on my lunch hour and on the third errand the starter cranked very slowly. I thought perhaps that I was taxing the battery with all the starting and stopping, but eventually adopted the belief that the starter had heat soak. After 15-20 mins she started right up.

So I head back to work, and 4 hours later when I try to start, no joy. Cranks very slowly. So on an off chance, I ask someone for a jump start, and that does not provide any results. However; on the last attempt I kept the key in the start position, the starter cranked slowly twice, then I heard a faint click and the car went dead. No lights, no interior lights, no brake lights, no horn, no nothin....completely dead.

I have replaced the fuses under the dash as well as the starter solenoid and verified that the battery has a charge. I can get no power to anything at all. I'll likely be spending an awful lot of time with an voltometer, but thought I'd check here first to see if anyone had experienced anything similar.

Any thoughts?

 

[Ronstang]

Have you tried cleaning up all the connections to the battery? Sounds like a bad/loose connection here or the solenoid could be causing your problem.

Sorry, didn't see that you changed the solenoid...have you had the battery checked?...and I don't mean with home tools, I'm talking about the testers at the auto parts stores that can tell if a battery is bad even when it appers not to be.

How about the negative battery cable to the block? And the ground straps from the block to the body?

 

[69PaleHorse]

Ahhh yes, sorry, forgot to mention that I also tried another battery and that did not solve the problem either. My bad for leaving out that detail.

 

[Ronstang]

Did you check the negative cable at the block?

 

[MustangPaul]

Did you check the negative cable at the block?

Wouldn't this cut the car out completely--no slow crank at all? Did you take your battery to a car parts place and have them check it?

 

[Pakrat]

Until you put a multi tester to it and verify every single section, basically everything will be a guess. It is possible that the ground has been slowly loosing it's contact to the block until it finally went from a partial draw to none at all, but I do agree that a slow crank starts to make the ground a less likely candidate than if he had nothing to begin with. Just stick your arm up behind the grill and try rotating the ground around the bolt from 9 o'clock to 3 o'clock a few times and try to start it again.

 

[Ozsum67]

Worse case senario, the thing is trying to lock up on you. I dought that is the case though. Could be your starter is fried.

 

[69PaleHorse]

Alright, been trying to diagnose with a multimeter. Is it normal to be able to get current (no impedance) from the positive battery terminal to ground on the block? hehe

I am beginning to think that I may have fried a fusible link somewhere in the main power feed harness...

Frustrating as all get out though, let me tell ya!

 

[blandq]

Here's my .02.

#1. Unless your real experienced or an electrical type ground issues and loose connections are difficult and can be a real mind-screw.

Loose connections and high E-fields (very much like those generated by a starter coil placed across the battery) can easily cause dendritic growth across the connection. This is where the copper migrates and oxidizes from side to the other, across the loose (gap) connection. all can seem fine....for awhile. Then slowly over time the oxidation builds up and replaces the gap or loose connection and eventualy goes from ohmic to resistive to an open.

#2. The process of elimination seems pretty straight forward here.
a. Try a direct battery to starter...go get an under hood button if arcs and sparks make you nervous.
b. if a above then re-introcude the starter solenoid but not the rest of the ignition system (i.e. you play ket with a 12 volt "on" to the starter realy coil.
c. if b above then continue to add in parts of the system until it no-workie!

At least this can eliminate via float test that items are as good as you think they are.

As an aside, but it can be a contributing factor, how big is the ground strap from your engine to the frame. The return path for the starter current, which is in the hundreds of amps the instant the relay closes, is through this cable, motor mounts (depending on style) and where ever your engine eventually through transmission, etc. bolts on to the frame. DO NOT rely on indirect connections to return this current, your engine ground optimally is matched to the cable going to the starter. If it's a 2 then the ground should also be a 2

 

[toyshop]

One usually accurate check for bad/weak connections is by checking "voltage drop." This is done with a voltmeter, connecting it in parallel with the circuit and then loading it to see how much "juice it needs to make the trip." Example: To check voltage drop in the ground cable, hook dvom pos lead to engine block. Hook dvom neg lead to battery post, not the clamp at the post- to the post. Now load (try to start it) the circuit. Usually 1/10 of a volt is allowed per connection. One connection is from post to clamp. next connection is clamp to cable. Next connection is cable to lug. Next connection is lug to block. Get the picture? This means a total voltage drop of .4 volts through the ground circuit form engine to bat. If you see for example 3 volts voltage drop, isn't it easy to see that a bad connection can cause a slow crank problem because you just sucked up three of your precious 12 volts just to "make the trip". Now only nine are left. I hope this helps somebody.

 

[69PaleHorse]

Spent the better portion of the day tracing out this problem, and I am not much closer to a solution. From the battery to the solenoid checks, solenoid main power feed to the firewall checks.

Now here is where it gets weird...inside the cabin, power to the pins on the inside of the firewall checks out, BUT when I put the fuse box back on I can't get power. If my testing is accurate, the fuse box is grounding out. Taking a test light and a small alligator lead, I connected the alligator to the power pin at the firewall and the other end to the test light - light is on. Touch the test light to the power receptacle at the fuse box and the light goes out.

More confused about this turn of events than I was yesterday.

 

[hdgapeach]

Jumping around too much. Go back to square one and start with the battery cables. Remove both positive and Negative and clean both ends of each one till the metal is shiny. Clean both battery posts the same way. Clean the ends of the cable from the solenoid to the starter. Now clean the attaching point at the starter and the solenoid. Clean the block attaching point where the negative cable bolts up. Consider replacing old cables. When you got the slow starter syndrome, you ended up overheating the cables and could have damaged them. Once everything is clean reattach all the cables and give it a try. You may have had 12 volts going to everything, but you could have enough resistance caused by corrosion on the ends of the cables, to reduce the amount of usable amps to turn the starter. When this is done, if you still have problems, repost and we'll go from there.

 

[L8knight]

Same prob before

I had the same thing happen to me with my 65 Ford Galaxie. It turned out to be the ground cable had overheated but it was not readily visible because the black covering didn't really show wear. Underneath however the copper was all burnt up and damaged. Replaced it and everything was fine.

It happened just how you described though; started having problems after frequent runs from store to store (hot days too), waited awhile after it cooled and it started. Then suddenly (fortunately at home in my driveway), nothing.

 

[69PaleHorse]

Jumping around too much. Go back to square one and start with the battery cables. Remove both positive and Negative and clean both ends of each one till the metal is shiny. Clean both battery posts the same way. Clean the ends of the cable from the solenoid to the starter. Now clean the attaching point at the starter and the solenoid. Clean the block attaching point where the negative cable bolts up. Consider replacing old cables. When you got the slow starter syndrome, you ended up overheating the cables and could have damaged them. Once everything is clean reattach all the cables and give it a try. You may have had 12 volts going to everything, but you could have enough resistance caused by corrosion on the ends of the cables, to reduce the amount of usable amps to turn the starter. When this is done, if you still have problems, repost and we'll go from there.

Thanks for the list. Completed all of the recommendations (save for relacing the cables) and still no joy. The strange thing is that I get power at the firewall, but the fuseblock itself is completely grounded out. Literally every terminal on the fuseblock has continuity to ground. I do not believe that tere is any electrical issue under the hood at this point, rather, I think the problem is from the fuse block back.

I had an issue with the ignition switch a long while back and replaced the cylinder, but am wondering if keeping the key in the Start position may have grounded out the ignition switch itself. Will be checking that next.

Oh, and thanks to every one for posting advice! Although we haven't found the culprit yet, some of your ideas I never would have thought to look at.

 

[pabear89]

Why you say the light is out on the fuse block,
Is the key in the on or acc position?
looking over the wiring diagram manual for my 70,
the Black w/yellow is the main lead for power from the batt.
and it also controls the keyed positions for power.

Do a bypass on the key switch and see if your getting power to the block.
disconnect the harness to the key and place a jumper wire to the differant terminals to check.

Getting a cont to ground on the fuse block shows that it is going thru the accessorys.

PB

 

[69PaleHorse]

Well, I took my car to the shop since I was obviously out of my element here.

You know how they say "It's always something simple"? Well, it was, sorta.

The engine had one, yes one, ground wire. It was from the battery to the block. And although this particular set up seemed to work fine for me over the last two years, it apparently is not sufficient. In fact, there was so much amperage running through the main power feeds that my starter was completely fried.

I have since upped the guage wire on the starter, and added an engine-to-frame and bellhousing-to-frame ground and all seems right with the world once again.

On a side note, while I was troubleshooting this issue, I found a ballast resistor in my ignition line. Since I am running a MSD Ready To Run dizzy and a pertronix coil, I don't need the resistor. Woohoo! Found myself a little ignition upgrade...and it only cost me three days and a couple hundred bucks!

All in all, I have to look at this as something that will undoubtedly make my car stronger. Better grounding is always a bonus.

 

[Pakrat]

Well, I'm glad to hear you are out of the woods, but once again we find the answer was in fact here first and for free. Rons very first and second reply for that matter:

How about the negative battery cable to the block? And the ground straps from the block to the body?

Had this been checked you would have discovered it's absence and could have added the braided line back yourself. Your expense has bought you some knowledge though and you really can't put a price on that. I think learning what we don't know about these cars is more than half the fun of ownership.

 

[Ozsum67]

Well, I'm glad to hear you are out of the woods, but once again we find the answer was in fact here first and for free. Rons very first and second reply for that matter:

Had this been checked you would have discovered it's absence and could have added the braided line back yourself. Your expense has bought you some knowledge though and you really can't put a price on that. I think learning what we don't know about these cars is more than half the fun of ownership.

And the part about the fried starter.

 

[69PaleHorse]

Oh, there is no doubt in my mind that I've learned from this site. And please do not think that I am unappreciative of the advice.

It is often said that doing the job right requires the right tools - to that end, I believe a good working knowledge of what you are trying to do is, in fact, a tool. Unfortunately, electrical is not something I have confidence in...and the 20-year old multimeter I have probably doesn't contribute much to the mix.

As I stated, this repair will undoubtedly make my car stronger, and now, should someone else here ever experience something similar, perhaps I'll have some knowledge/experience to share.

Thanks again everyone!