i have an 84 with 7.3 swap. i did not do the swap but the problem seems to have developed a long while after it was done.

when i bought the truck i originally had no problems, however after the first time the batteries died (last winter) i have replaced both batteries (850 amps), new alt, new volt regulator. i have checked my big wires and they seem to be in order (no swelling or cracking) though i didn't get the chance to clean the ground connections. terminals are in good order. dash gauge reads that it is charging batts.

after leaving batts on the 2amp (i have to run 100' of cord to my charger) over two nights, one for each batt, i started and drove to my buddies house. seemed to be fine til i left, it started up turning over like it had full juice and died (odd) right after. had to be jumped and then headed back home.

went through same ordeal charging batteries, finally got it started back up, drove up and down the street for a while, then parked it again. that was about 2 weeks ago. went to start it today and its out of juice again.

i looked at the wiring from alt and it looks fine but in the mess of wires i am not sure what i may be missing. in the included pic there is a broken plug (so connections to whatever it goes to are kinda loose, but making contact) also there are two boots that i'm not sure about, might be from 6.9 harness or something but i'm not sure. starter solenoid has a third boot on the S, nothing on I.



Uploaded with ImageShack.us

any thoughts?

 

I am not sure(and I don't think you are either) that the problem is the charging system. I see that it could be 1 of 3 problems;

1. It's not charging.

2. There is a drain on the system when it's sitting.

3. There is a connection problem in the large wiring.


To test out #1, get it running and check the voltage on the batteries. If it is 13.5-14.5v, then it's charging.

To test out #2, take your driver's side battery terminals off, and carefully wrap them in rags or something to insulate them. Then take the passenger side battery negative cable off, and hook a testlight like the picture shows below. If the light glows bright, you have a drain problem.



To test #3, turn the headlights on and get someone to watch them as you try to crank the engine. Do they go out completely, or stay fairly bright. Did they come on at all?

 

i found my multimeter today and went to do some checking, unfortunately i couldn't get it to turn over so i couldn't check to see if the batteries were charging. i did however read the voltage from the two booted wires i was holding in the picture, and the black wire is reading 12V, should it be hooked up to something? it is in the same piece of wire loam as the wire going to the S on my starter solenoid. the red wire however showed nothing (this was with key off, didn't test with key on). i'm wondering if this may be associated with my no start issue.

to test #2, i don't have a test light, is there a way to test with multimeter and if so what should i turn the dial to? what reading should i be looking for?

#3 the lights stayed about the same.

i'm leaning towards there being an issue with the wiring associated with turning over the motor, i had full 12.7V when i started and used a couple shots of ether, still with no luck. my manual glow plugs light up for the first 2-3 clicks and then it seems to be at hot enough temp to start after only pushing the button for a second. (its been in the triple digits for weeks now)

i wonder if i should buy a new fuel filter/put some type of additive in the fuel to help with starting? i just changed the oil with rotella (15-30 i believe) a month ago, but the truck had sat for about 4 months prior. directly before that i had changed the fuel filter with a new wix one, though, and pulled it off today to find no gunk buildup or anything in it. but the fuel in the tank is a solid 4-5 months old by now.

help is appreciated!

 

The lights staying bright (they act like a crude voltmeter) are telling me you have a wiring problem. Since they stayed bright, that's telling me the batteries are up and connected to the wiring in the truck. Not dimming at all when you are trying to start it tells me there is nothing happening at all, no connection is being made to the starting system. You are not saying that you are hearing any clicking either, so I am going to assume the start relay(solenoid on the fender) is not getting power.

From the picture above, it seems like you may have some gasoline parts and some diesel parts mixed together. In the picture, see the wire on the solenoid with the red 90 degree boot? Take that wire off, and take a short piece of small wire and touch this terminal to the large terminal to the left in the picture that goes to the battery +. Does it crank? MAKE SURE THE TRUCK IS IN NEUTRAL OR PARK BEFORE TRYING THIS You don't want it to run you over.

 

it did turn the motor, and being able to watch the lights myself (i had my wife watch them for me before) i can see that they are dimming slightly when cranking.

the only clicking i can hear is the glow plugs.

i'm wondering how i could have a mix of gas and diesel parts? are you talking about the harness itself or the starting hardware (solenoid etc). from what i was lead to believe, it was originally a 6.9 truck and had a later 7.3 dropped in, neither of which would have called for gas parts so if there is something i don't understand why ol boy would have even bought it.

i'm wondering if perhaps there is a wire i missed when hooking up the new volt regulator. or the alt. its been a while since i swapped those parts out (6 months at least) but i recall starting and driving on a few occasions since then so it seems to be a more intermittent problem and surely a wire not being attached would make for it never charging or starting, not just hit-and-miss.

would i be looking for 12v on the red booted wire to the solenoid with key in the start position and no other time? would that solve whether or not the solenoid is getting juice?

 

I didn't know it was cranking. That means the batteries are good, the starting system is ok, etc. Are you getting white stinky smoke out of the exhaust when it cranks? If not, you are not getting fuel, and I would make sure you have 12v on the wire going to the injection pump. If you have 12v on the pump wire, I would look at the fuel filter mount on the engine, there is a valve with a cap on it that looks like a tire valve. Poke it with something and see if fuel comes out. If not, you have a fuel supply problem. You can unscrew the fuel filter and see how much fuel is in it.

If you are getting white smelly smoke out of the exhaust, you are getting fuel, so your glowplugs are not heating correctly, or the engine is not turning fast enough, etc. This engine fires on the heat generated by compressing air. Cranking speed, glowplugs, etc. generate enough heat for it to fire. If you think this is a problem, you could plug the 110v block heater in if it works for a couple of hours and then see if it fires off.

I just thought you might have gasoline parts because you said the word "swap" and it looked like you have the wrong starter solenoid on the fender(but it will work, and it might be correct for a early truck like yours).

 

We are very literal here....

"Turn over" means the starter motor turns, engages with the engine and turns it.
It does NOT mean "start the engine."

 

block heater is currently plugged up, i am showing 11.7V to both wire mounts on top of injector pump with key in RUN. also checked voltage on alt and both the larger ring terminal wire and the small clip-on wire are reading 12V.

i pushed on the valve you spoke of, and no fuel came out. however when i pulled off the fuel filter it was only about half full (i went ahead and refilled it). should fuel be coming out even with the truck off?

also, if the truck starts after having the block heater plugged in, will that narrow down my problem to gp's?

 

You will not get fuel from the schraeder valve until the engine is cranked. Its possible the filter drained because you let air in at the schraeder valve.

 

that makes sense, i didn't understand how a valve above the filter would let anything out without any pressure behind it.

anyway i let the block heater run for an hour and a half, just went out and turned it til the batteries sounded too weak to start it. unscrewed fuel filter, and it is once again half full (truck never did fire at all)

would that make it a fuel pump problem? don't these trucks have a mechanical fuel pump?

i'm completely at a loss here since i used the truck as a DD road truck up until about Feb/Mar when it developed an oil leak and i didn't want it to break down out on the road. never had any problem with it before and after sitting for a couple months it just refuses to run.

 

How long is your "Glow Plug" light staying on? If the glow plugs and/or controller are working correctly. The light should stay on 10-15 seconds for a cold start. Also Do Not use Starting Fluid! Unless you have Disabled the Glow Plugs! Serious Damage to the Motor can happen.

 

Those wires look like they go to the Glow plug relay. Looks similar to the Starter relay in the picture. But it should be mounted near the Voltage regulator.

 

Looks to me like you have a fuel problem. You should get a squirt of fuel anytime you push on that shrader valve. If it drains back over time, that's a problem too, the fuel cannot drain back to the tank.

Pull the line off that comes from the fuel pump down on the front pass side of the engine, put a hose on it into a bucket, and crank it and see if it pumps fuel into the bucket.

If you do not have any fuel, how much fuel is in the tank? These trucks have a large plastic fuel pickup inside the tank that looks like a shower head, and these are famous for breaking off. When that happens, you get down around a 1/4 of a tank and you run out of fuel. There is a fix for this also.

 

i have manual glow plugs, as soon as i turn the truck on the light comes on for a hot second then starts clicking, and gets successively dimmer with each pulse or after i have held the button in for 15-20 seconds. i use ether on occasion.

 

here is a picture of my glow plug relay. one prong looks as though it may have had a boot on it, would that be the one that reads 12V (i believe the key was OFF at the time) or perhaps the other? the second wire didn't register at OFF, should i check the voltage at RUN?



Uploaded with ImageShack.us