Another No Start Thread

[bigblu78]

Alright... I have another 88 F-250 with the 7.3 and the C-6. (I know.. I should have stuck to just one but now I have 3 !!) Anyhow, I use this one for beating around the farm. Doesn't really see any road time. I have constantly had a problem with the batteries going dead and I have yet to find the issue there. Tried all the tricks to find the draw but I have had no luck. Now, I cannot get the truck to turn over hardly at all. It will spin but VERY slowly. As for new parts and things I have tried:

2 new 1200cca batteries
Alternator (Orielly's)
2/0 cables EVERYWHERE (Interstate Battery)
voltage regulator (Napa)
starter (Mits)
solenoid (Napa)
checked all of the connections and grounds.
new ignition switch (Napa)

Today I took the starter back off and swapped it for another new one and it does the same thing. Even when I have the truck on the charger or jump it off of my Pete, it still BARELY spins at all.

Hopefully someone can shed some light on this for me because I am stumped. I've been through every wire, connection, and electrical component that I can think of.

Thanks,

Troy

 

[Agnem]

Do the headlights stay bright when you crank it, or do they dim?

 

[bigblu78]

they dim...

 

[BigRigTech]

Is your GP circuit staying in when the truck is off? You need to go one circuit at a time, disconnect it and see if you still get a spark at the battery terminal when you take the cable on and off....To kill two 1200cca batteries it must be a significant draw like the starter, alternator or GP's.... Have you checked all your grounds really well, I mean remove them and clean them?...Are you sure that it's a draw and not a bad charging rate not charging the batteries when it's running?...Time to think outside the box....I had this problem with an alternator and external voltage regulator that were wired incorrectly.

 

[Pipeliner_86]

I know you said you've reworked all the cables and connections, but its my opinion that you problem lies in the connections.

 

[Full Monte]

What is the voltage of your batteries at rest after about 2 hours of sitting?
If the batteries are low, you likely have a drainage problem.

 

[bigblu78]

Is your GP circuit staying in when the truck is off? You need to go one circuit at a time, disconnect it and see if you still get a spark at the battery terminal when you take the cable on and off....To kill two 1200cca batteries it must be a significant draw like the starter, alternator or GP's.... Have you checked all your grounds really well, I mean remove them and clean them?...Are you sure that it's a draw and not a bad charging rate not charging the batteries when it's running?...Time to think outside the box....I had this problem with an alternator and external voltage regulator that were wired incorrectly.

Alternator is working perfect as did the one I just removed. All grounds have been removed, replaced and prepped with die grinder. My GP system will drop my charging system down to around 9 volts when on. When my WTS light goes off (around 10 seconds) my system will jump back up to around 14 volts about 5 seconds later. Can you explain the wiring issues that you have had with your voltage regulator and alternator. When I got this truck I was carrying spare voltage regulators with me like I do fuel filters. I would loose one about every month or two. I thought it was due to cheap parts so I put a NAPA part on an haven't had it go bad since. I did just replace it again when these problems arose.

I know you said you've reworked all the cables and connections, but its my opinion that you problem lies in the connections.

Last night I went back out again and used my die grinder to clean all the ground connections one more time. I also inspected the new cables again. I did find that a ground strap was frayed pretty bad from the firewall to the block. I ground the connections down there as well and replaced that. I am to the point with this where I am about ready to start removing and replacing one wire at a time to eliminate an interal crack or break. I have also replaced every fusable link that I can find. Is there any other connections that I am over looking? Is the 2/0 cables big enough or should I have gone to 1/0 for the ground?

Just as a note. I don't like jump starting things but I broke down and tried to jump the pickup with my Peterbilt. I figured that should get it going.. NOPE... still the same thing.

Thanks again for all of your responses. You've all been a great help.

Troy

 

[BigRigTech]

Basically there was a wire on the VR that was on the wrong terminal so when the engine was running the alternator was in "full field" mode putting out maximum amperage but when it was shut off it was drawing back the power fron the battery....The only wire on your alternator that should have power when the engine is shut off is the main wire going from the positive post on the alternator to the starter fender relay....The other wires should all be dead.

Like I said above, start unhooking things that could draw if faulty or wired incorrectly one at a time.....If you still see a "spark" when you take the positve battery cable on and off then something is still drawing. Keep unhooking things one at a time ( leave the previous items unhooked) until you don't see a spark and bingo! you've found your problem ciruit....You could also hook a decent amp meter inline with the positive battery cable and positive battery post to see how much amperage is actually being drawn and unhook the negative cable or buy a clamp on ampmeter and start testing circuits that way....First I would make sure you have two fully charged batteries and make sure your alternator is actually charging. Good luck.