Battery/electrical issues. I'm stumped

[Ben5959]

I'm having issues with my 66 c10 327. For reference I've put in a brand new alternator, battery, starter, voltage regulator, carburetor, plugs, plug cables, and distributor coil.

The issue I'm having, everything will be running fine, until I do some serious driving, over 10 miles or so and definitely each time I'm on the highway. After driving, the next time I go and try and start it has a hard time starting as if the battery is not charged enough. Eventually it will start after cranking for a bit, but every few trips this happens, it won't start up at all. Lights will turn on in the cab, but there is not enough juice to crank it over. A quick battery jump will get the truck going, and everything will be fine for a week or so. Then it all will happen again after about a week. At this point, other than replacing all of the wiring. I'm stumped

[jtrichard]

check the battery voltage before you start and when running and see if its charging

[Palf70Step]

Could also be the starter/starter solenoid overheating, but I would start checking your battery voltages and charging voltages

[Hugh in NC]

If your initial timing is too high, engine will be hard for starter to turn over after warmup. If all the above stuff checks ok, lower timing by several degrees and see if it helps.

Hugh

[T and S]

Just guessing, but sounds like a heatsink problem. Heat causes more resistance in your wiring. Does it start ok after it sits awhile, or on cold starts ?

[par4tom]

Go through the process of elimination. Use a volt meter to check the battery voltage before your first start and then after. Also, check the voltage with the truck running. At rest, the battery should be about 12.3 to 12.7 volts. Once started and running, I'd look for 13.7 to 14.1. Also, be sure and check your voltage from the battery to the starter --- but check the voltage on the starter side this time.

If that all checks out, I agree with one of the earlier writers, check your timing. Too much advance and the spark will be going off too far before TDC and that could be the issue...especially when it gets warm.

If both of these are ok, then it probably is a starter/heat issue.
Tom

[buds56]

I would take a look at the battery cables, If they're old or small, replace them and bump up a size so they can carry more current.
Hope this helps

[Ben5959]

Originally Posted by T and S

Just guessing, but sounds like a heatsink problem. Heat causes more resistance in your wiring. Does it start ok after it sits awhile, or on cold starts ?

The voltage is reading right, it starts fine when it's cold. Just not when warm/hot.

[geezer#99]

You need to wire in a remote solenoid and kiss your hot start troubles goodbye!
http://www.madelectrical.com/catalog/st-1.shtml

[trooper61]

You didn't say but If you have headers then you need a heat shield on the starter. I had the same problem years ago.

[dougf]

Same issue years ago and it was the starter. Good luck!

[Greg63]

I recall having an issue just like this about 20 years ago. I went to the remote solenoid route and that fixed the issue but it killed me knowing I had to add a F*%D part to keep my truck running.
Eventually I was given 1968 C10 Repair manual so I went over it out of interest sake and I found a difference in the wiring between 1963 and 1968 on one wire under the hood. IIRC in the 1963 harness that goes to the starter from the right side of the firewall the was an 18 ga wire that was upgraded to 12 ga in the 1968 trucks. I changed that wire in my truck to 12 ga and I never needed the solenoid again.

Might be worth a look to see if it helps you out.
Greg.

[jtrichard]

Originally Posted by Ben5959

I'm having issues with my 66 c10 327. For reference I've put in a brand new alternator, battery, starter, voltage regulator, carburetor, plugs, plug cables, and distributor coil.

The issue I'm having, everything will be running fine, until I do some serious driving, over 10 miles or so and definitely each time I'm on the highway. After driving, the next time I go and try and start it has a hard time starting as if the battery is not charged enough. Eventually it will start after cranking for a bit, but every few trips this happens, it won't start up at all. Lights will turn on in the cab, but there is not enough juice to crank it over. A quick battery jump will get the truck going, and everything will be fine for a week or so. Then it all will happen again after about a week. At this point, other than replacing all of the wiring. I'm stumped

Can you get a good pic of the starter at the solenoid? Are you still running points? there are many things it could be need more info like main cable sizes? what is your timing set at? is hot start still hooked up? Secondary solenoid/relay is only needed if when hot it wont crank at all... sounds like yours is cranking when hot just maybe slow.... so second relay wont help your problem

[OldChevy61]

Had the same problem. Had 3 places check battery and they said it was good. Put a new one in it anyways after getting stranded at Walmart,no more problems. Bad starter will also cause it if its hot.

[siggyfreud]

I agree that it sounds like the starter solenoid is getting too hot. Would explain why cold starts are fine, and warm starts are a problem. Remote mount the solenoid, or protect the starter with a heat shield or wrap and I bet the problem goes away.

[Hansome]

Hi,
Thought I would just my 2 pence to the list......

Not because I have the right answer but in doing so you maybe able to eliminate some of the other things off your list.

I had been chasing a similar problem to what you are describing, starting from cold not a problem drive to work/ builders yard turn off engine go and sort stuff , jump back in the truck and Ffffzzzzzzz nothing just dead. So get a jump from another a vehicle starts up fine and strong no problem for a few days. Then after a good drive the same thing would happen.
1st thought - battery not holding charge = not enough volts to crank the engine over.
2nd thoughts - alternator going south and not charging the system properly
3rd thought - starter motor solenoid going too
4th thought - ignition switch
So ordered all new of the above and from USA an awaited them to arrive from over the water......... Too many days later they arrived and up to this point the truck is still having the same problem.
The P/O had also had an issue and had chased it around and thought it had been fixed.
So fit all of the above new part - thinking this would solve the issue and it didn't ....... I then read some where about the neutral Saftey switch could cause a problem so removed the 49 year old one to find out that the prong was mashed up - popped in the new in I had and turned the key and ............... Fired up first time and has doene every time since that day 4 months ago all the electrical gremlins that were making me miserable dissappeared ,until this morning!!!!
Disheartened I set about the process below to solve the problem.
Open the bonnet / hood
Get a multimeter test the the volts on the battery with the ignition off
Then get a test light hook up the lead up to a good earth ( test on battery + light should come on)
Then locate starter / solenoid then look for the purple wire that runs to the smaller connection on the right hand terminal - ( your facing the starter with the 3/4 terminals pointing back at you)
Then turn key in ignition to on but don't crank -
Go back to under the hood and put your test light on that terminal ( with the purple - original colour wire)
If the test light glows then it's not your ignition - if it doesn't then trace the purple wire back to fire wall terminal to check for damage or all the way back to the ignition terminal under the dash.
This was the problem with mine today as I had no test light connection when key was on but was showing 12.2 v on the battery.
Thankfully I have a remote starter in the glove box so connected that to the purple wired terminal on the solenoid and the big (top centre ) connection direct from battery and she fired right up - that got me started and home.
Meaning tomorrow's job is run a new length of purple wire from the ignition cylinder to the starter solenoid.

What's was stressing me out was I couldn't work it out I tested this I tried that - but it needs to be done in a methodical manner - I tested the battery and it was holding a decent enough charge to crank it over but would ( but I knew it could) so I changed everything over to solve the problem. This is where I should have taken it one logical step at a time but you know this whenever your doing it ,but you get frustrated and you start going off on a tangent.

I have to say having a test light and a multimeter ( and learning how to use them properly ) are the best and relatively cheapest things I've brought to fix my truck and it has proven to be invaluable
Today breakdown diagnosed and fixed in 20 mins - but that's because I have spent months (years) breaking down and trying to work out how to fix things . Learn by doing/trying

Ok so I notice I've gone on a bit - it's late and I'm "drinkIng and typing " ........... Where's that spellcheck thingmejig 🔙🔛🔜
Posted via Mobile Device

[franken]

A slow crank issue isn't the solenoid unless the contacts are burned.
You say the battery voltage is ok, but don't say what it is. What is it to the nearest tenth?
Once the solenoid switches the starter on, there are 4 things involved, the starter, 2 cables and the battery.
The reason a ford solenoid fixes a slow crank problem is part of installing it involves fixing the wiring that's causing the problem. Fix the wiring and another solenoid is not needed.