Went out to start the truck yesterday and it started up just fine. After sitting for a couple of hours, I tried starting it and I could tell the batteries were weak and I was worried that it wouldn't start but it did. It did this to me again about two hours later and then started fine two hours after that. However, I went to start it this afternoon and it would barely crank. I stopped by an auto parts store and had them check the batteries in the truck and they said they were good. I'm not sure if they checked them right...what's the procedure for this in our trucks?? Pretty sure the auto parts guy had never seen a diesel before. I did notice that the CCA were about 620 on the test, and the batteries are rated for 880. Could it be a bad cell or anything else shorting them out? Ohh...the batteries are about four years old and the truck has 193,000.

 

It sounds like your alternator is not charging. I had one really bad battery and one that just passed the test and the truck would still start. I still have the original alternator on mine with 222,000 miles, knock on wood.

 

ohh yeah...forgot to mention I replaced alternator last summer. And the batteries showed low voltage (12.5) with the truck off and were up to around 14.5 with the truck running, so I think the alternator is doing it's job.

 

Double check and clean all the connections even at your starter. Maybe take it to another part store and see if they come up with the same results.

 

12.5 with truck off is correct not low but if each battery only tested to 600 some cca that is not enough. and did they disconnect on battery and test each of them seperately? i would have the batteries tested somewhere else and make sure they disconnect one of the batteries and test each seperately. you make also have a parasitic draw when the truck is sitting if the batteries are fine. but that is where i would start so keep us posted.

 

I don't think I'm having battery troubles as much as I am thinking that something must be shorting them out when I turn the key. The batteries are at 12.5 volts without the truck being on, which I think would be sufficient to start it. I've checked all the connections to the starter, batteries and ground. I was reading about the fuel heater shorting out against the side of the canister, but the wait to start light is still coming on which would lead me to think that the PCM isn't shorting out. The number 18 maxi fuse which charges the trailer battery circuit is blown, but I'm not sure how it would have happened since I haven't had a trailer hooked up for a while. Unless there is just a wire shorting out somewhere. Not really sure where this circuit runs and if it would drain my batteries as soon as I turn the key. Anyone have any ideas about this situation??? I have also tried charging with a battery charger and still have no luck.

 

The trailer charge circuit is in a bundle that runs down the driver's side frame rail from the power distribution box to the seven-pin trailer plug on the rear bumper. If the fuse is blown, it shouldn't be causing the trouble. It also has a relay in the circuit that will only allow the circuit to operate when the engine is running. Has the problem cleared up since the fuse blew?

Gene

 

No the problem still hasn't cleared up, and it should start if the fuse was blown and not allowing the current to source back to the battery. Any other ideas on what it could be?? Is the trailer circuit the only one on that fuse?

 

On my '95 F350 the trailer battery charge is on a separate 30 amp Maxi fuse.

The glow plug circuit will drag the voltage way down while it is engaged. You might try waiting about two minutes after you turn the key on and see if the voltage goes back up to around 12.5 before starting. You may have a short or heavy draw in the GP circuit.

Gene

 

I was thinking something in the gp circuit as well. I tried what you just mentioned and the glow plug relay doesn't click like it normally does when I try starting. However, with the key off, one side is hot (12 V) and the other is 0 V as it should be. The battery voltage drops to around 11.4 volts with the key on, but it does seem to recover only up to about 12.15 V after the relay kicks off. It still didn't click as loud as it normally does though. The truck still won't start either. It acts as if the batteries are severely drained. I need to pull the batteries and have them both load tested on the stand at a parts store to make sure they still aren't the culprit. Any ideas of what it could be in the gp system??Thanks for your help so far!

 

A lot of people have reported burned wires or contacts in the under the valve cover wiring or in the valve cover gasket where the terminals pass through it. A bad glow plug has a high resistance too, which is probably what leads to the burned wires or contacts.

I would think that it would crank on 12.15 volts though. Does it turn over and just not crank or what?

You could use the block heater for two or three hours just to rule out the glow plugs. They will crank fairly easily, even with bad glow plugs when you plug them in for a while. You might also try adding another battery to the circuit with a set of jumper cables to see if it will crank. If it does, then I would suspect the batteries or a bad connection.

You mentioned having the batteries bench tested, which would also be a good idea. Go ahead and clean the terminals while they are out, even if they look fairly clean.

Gene

 

I have read about the burnt wires and contacts, but was hoping not to have to take the valve covers off. I think I am going to pull the connectors and check the glow plug resistances and see if I may have a bad plug. I also have plugged the block heater in, but it has not had enough time to heat up yet. Also added a battery from another truck and ran the charger on the start mode to the circuit. The truck will turn over, but only about once before the battery is dead. I think even with the block heater plugged in, the batteries will discharge too rapidly for the truck to start.

 

Just got back from getting the batteries tested and one tested "marginal" and the other was just completely bad!! I'm glad I tested them before I dove into everything else. They're carquest batteries w/a 70 month warranty so at least I'll get a little money back since they're only 4 yrs old. Thanks for the help, hopefully this will be the fix.

 

Good deal. You might want to follow up on your GP circuit too if it had trouble starting (turned over good but hard to start) when it was colder.

If your lucky, the batteries will be the whole story.

Gene

 

97 red psd did that do the trick? If not check number 22 fuse. the fuel heater on my truck shorted out and would not let the truck start. the fuel heater is on the side of the bowl where the fuel filter is. if you need more info let me know