wheelieking71

the crimps on all the heavy ga. wire were done by me, with a proper crimping tool, and just about as hard as i could swing a 5lb. sledge. high quality copper terminals, and good 2/0 weld cable. also, corrosion is not a big problem here in AZ. i understand the rules for electrical connections are different. but, its still not a big problem. the power for the fusable link delete comes from the starter hot post. it, the alternator, and the battery positive all meet there.

so, what would cause the volt meter to jump around at low idle the way it does? that seems to have a correllation to the problem. if the meter is jumping around when i mash the throttle, it cuts out. if the meter is reading smooth when i mash the throttle it runs good. i have tested that thoery many times now and it is 100% accurate. and it only takes very slight throttle pressure (maybe a 75-100rpm rise) to get the volt meter to smooth out. it is a new alternator, but that doesnt mean its a good alternator. as a matter of fact, it came from Orielly's, and i have had very bad luck with electrical parts from there. (it took me 2 trips to get a good starter for my daughters honda, the dimmer switch i am controlling my overdrive with is the second one in 2 weeks from there, and a few other things)

j_martin

There aren't many things that would do that. Bad connection, (I know, you swear it's impossible.) bad battery, direct high current short to ground. If the last one occurred on anything but a major power cable, it would instantly melt the insulation on the wire.

Food for thought. If the alternator is wired heavy, and is shorting internally, that would do it. To eliminate that, you could disconnect the alternator, and take a test drive running on the battery.

Next step would be to hook up a couple of cheap analog voltmeters. (needle, so you can see it wiggle or jump, but ignore small fluctuations that will drive you nuts with a digital read out.) One would go to the battery, and the other to the supply wire at the FL delete. If the battery one blinks, both will. If only the FL delete meter blinks, it's the supply wire for that.

BTW, have you tried the alternative supply for the FSS trick yet?

I'm having flashback nightmares about tracking down wild neutral problems in a computer center power system.

j_martin

I have seen diodes alternately short and open. One instance was in a big mainframe printer. (IBM 1403-N1) It would blow a card, then work for a day, then repeat. Drove 4 certified IBM engineers nuts for a week. Took me about an hour to find it analyzing the matrix of faults. That was the first 1403 I ever worked on.

wheelieking71

thank you again for more great ideas on troubleshooting. im not swearing that a bad connection is impossible. just that if thats what it is, i cant find it LOL. and im not just looking at stuff. i have taken lots of stuff apart. cleaned grounding surfaces. checked the integrity of connections and crimps. most anything that i have assembled smaller than 4ga. gets soldered. bulkhead came apart. spent a whole can of contact cleaner on it. gave every single female receptacle a little tweak to solidify the connections. reassembled with a liberal coating of dielectric grease. there is a silver lining to this problem LOL, this is all maintenance stuff that hardly anybody takes the time to do. (except maybe Jim Lane!) well, im being forced to do it through my inexperience of troubleshooting electrical LOLOL. and i dont mind doing it, as long as eventually i figure it out. but i really would like to get back on track with my "project". right now it has me feeling like this:

longshotranch

This might sound stupid but what is a FSS

wheelieking71

FSS = fuel shut-off solonoid

j_martin

Here, let me help.

I think we have the matrix down to supply to the FL delete, hard short or open on a heavy supply cable. (maybe the alternator) or the battery itself.

I'm thinking if it cranks well, the battery is probably OK. Usually if you have a weak internal connection, they'll either crap out or blow up and crap out when cranking.

tech-eh

j martin I think is on to something....... you swapped out regulator hows the ground on the regulator ???????

wheelieking71

okay, i did the isolated battery on the FSS tonight, and you are absolutely correct j_martin. truck ran like a scalded zebra. with the lights flashing and all! swapped the ignition switch. still cuts out from a dead stop with heavy throttle. although! the volt meter is now a little more steady. still twitches a teeny bit now and then. but much better. next step, run a temp power wire from the alternator hot post to the FL delete hot post. this should isolate the existing power wire for the FL delete. then if it still does it, i will swap the alternator. then if it still does it, i will swap the battery. then if it still does it, i will completely remove all the power cables i built from the truck, and inspect them 200%. although, i really dont think that is the problem. i feel that the only power wire it really could be is the 4ga. that runs from the battery hot post, to the FL delete hot post. that one wire feeds the whole truck really. i think if it was the battery, or its 2/0 cable running to the starter, the alternator would pick up the slack. if it was the alternator, or its 4ga. charge cable that runs to the starter, the battery would pick up the slack. the chances of it being both are slim to none. that leaves the 4ga. from the starter to the FL delete. (yes, your thinking is perfectly logical! and i agree!) i also need to do like you said J_martin, and rig a volt meter to the hot post of the FL delete. that way i will be able to tell if im loosing power before, or after the fuses. i think? LOL. i dont have an analog gauge. is it possible to pirate a gauge from an instrument cluster? i have a few of those laying around. i also can see why you think it is torque related, but, if it was, wouldnt it also do it brake-torquing at a standstill? i have taken it right up to converter stall and then some with the hood open, and watched the engine roll right up from the torque. but it wont do it then.

j_martin

You could do that. You could just use a light bulb. Yer just looking for the blink.

Next, I'd try just disconnecting the alternator. If it doesn't blink, the alternator is bad. The other tests, like a temporary wire, won't be valid if the alternator is shorting.

Headlights don't go through the ignition switch. If any ig. switch circuit grounded enough power to blink the headlights, it'd take a fuse out of your FL delete.

wheelieking71

cool, unhooking the alternator is EASY!

tech-eh

ya know what I think its a lose diode connection in side the alternator as in cold solder joint on the end of the diode bank . I believe wheelie king stated he has changed the voltage regulator
so that is out or a reg with a short internally due to the sand inside the regulator being wet internally. keep at it Wheelie this is interesting not a problem I have seen In along time .......

j_martin

What we have here is major power failure, which has to be either a high current short to ground (which usually makes smoke) or a loose connection in a high power cable.

The only reason the generator is even suspect is that it is capable of the short, and the trouble seems to have started near it's replacement time.

wheelieking71

yep, no smoke yet. and when it happens it definitely kills the whole truck. the alternator is about 1yr old. (maybe). the fact that it ONLY happens from a dead stop with heavy throttle input screams that it has something to do with engine movement. i will know the verdict on the alternator in about 1hr. and go from there. j_martin brought up a really good point earlier that the headlights dont get power from the ignition switch, but all the other lights do. that means i am loosing power to everything. that really narrows it down to the alt., the batt., or about 30ft of wire. wire that I installed. see the 3 cables circled in red here:



the large one is 2/0 straight to the B+ post on the battery. if it shorted the truck burns down LOL. the 2 4ga, one goes to the hot post at the alternator. the other feeds power to my fusable-link delete. circled in red here:



with j-martin's help i have it narrowed down to the circled post in the last picture OUT. i think! LOL

wheelieking71

Alternator disconnected did NOT solve the problem. It still cut out under heavy throttle from dead stop. Next up: swap out battery.