How F***ed am I

[DailyDato]

Ok community, I need help, and I need advice, I will try to the best of my understanding to explain, I have a 77 620, DE swap, IR alt, w/ Regulator delete, wired properly. The truck is great, until at complete and utter random, ALL FUSES blow, and truck shuts down completely.....this is the start of my problem, well its been four days now, and i looked through 14 or so pages of electric, and arent finding many answers, SO, in the last few days, I gutted my harness, completely checked every wire for shorts, nicks, scrapes, burn, etc, found a few melted wires, not burned, just kinda drippy looking insulation, but nothing severe, fixed them, added some grounds into the harness, and reinstalled, truck started and ran great, pull on the lights, running light? good, head lights? good, pull on the wipers, low? good, high? good, pull on the blower, No low speed, and on high, the head lights dim (high beam or low, dont matter), and the wipers slow, ok? weird, checked brake lights, working, reverse lights work, Hazards and turnsignals work, except every time they blink, the rest of the truck dims, Alternator charges at 12.9-13.7, adequate enough, Gas guage no longer works, temp guage is not hooked up, charge light works and goes out properly, beam indicator light works,

 

So in conclusion, everything "works" except temp guage, not hooked up tho, my fuel guage, but not worried about it, the main part is that the truck goes dim and flicker and goes normal with the turnsignals or hazards on, but now for the kicker, the black wire from my battery that powers the fuse box, gtets smoking hot, and the insulation trys to sag off, The DE is wired properly and correctly as of the instructions provided on here, proper fuses, proper relays, everything is great, truck runs and drives like a beast, I feel the issue is in the stock truck harness, but where, everything works, but why is the amp load buring such a larger wire, and not a smaller one? I have added too many new grounds, and ohm all the wires in the complete harness, NO SHORT TO GROUND, NO SHORT TO POWER.......Only mod to stock harness, is remove all unneccessary extras, and upgrade to new bulbs, 194's, 1056's 1157's and the reverse lights and tag lights, ?168's? OH and the little turnsignal idc. bulbs too I do not have a radio, cig lighter, interior lamps, no door switches, just bare needs, the horn is not even wired, no seat belt lamp, no W.e light is next to the seat belt light, bare minimum, Any ideas? anyone, Lest all just get involved and someone ask me something new, and see where we can get to, Oh BTW, its supposed to be my daily, and I cant go anywehere, good thing i live nextdoor to my job, and the other side of work,....Is Orielly's

[MicroMachinery]

I thought this was gonna be another butt lice thread..

[wayno]

I have never heard of every fuse blowing at once, doesn't sound good. I hope you find the issue.

[DAT510]

Replace relays maybe? Try eliminating all possibilities

[Jester]

Pull your fuse box and check behind it to see how it looks. Maybe something fell back there and is causing a short. That is the only thing I can think of that would cause a short on all fuses at one time.

[yello620]

Are you using molded style battery cable ends or those peice of crap bolt on cable ends?

 

You can add lots of grounds to the system, but none of them do you any good if the one attached to the battery is marginal.

[Guest kamakazi620]

Do you have a proper sized fusable link???? or did someone replace with a small gauge wire??

[yello620]

Agreed on the fusible link, if it is overpowering the system in a manner that blows all the fuses, it should have had a fusible link go first.

 

However, the fusible link is not the source of the problem. I suspect you have a major wire causing this(battery cable).

 

Another thought, is your fuse box housing melted at all??

 

 

And since this is the third thread that you have started regarding very similar wiring problems, have you resolved any of the other problems that you were having??

 

http://community.ratsun.net/topic/35061-help-ratsun-community/page__p__536309__fromsearch__1#entry536309

 

http://community.ratsun.net/topic/35030-um-620-wiring-help/page__p__535425__fromsearch__1#entry535425

[Guest kamakazi620]

Agreed on the fusible link, if it is overpowering the system in a manner that blows all the fuses, it should have had a fusible link go first.

 

However, the fusible link is not the source of the problem. I suspect you have a major wire causing this(battery cable).

 

Another thought, is your fuse box housing melted at all??

X2 on that check that fuse block

[albyneau]

More info needed~ which other wires showed evidence of overheating? How intermittent is this? Can you duplicate by jiggling the wires/harness? Have you stripped all harness wrapping to check for hidden chafing?

 

My 521 doesn't have an IR alternator; yours has the regulator delete mod~ but there might be common ground here (excuse the pun). I had some quite similar symptoms (less the melting fat wire) that turned out to be an intermittent open in the wire that goes from the alt to power the charge indicator lamp~ gauges & lights worked voluntarily, alt full-fielded and cooked the batt dry (mystery melted wire?), yet showed low borderline voltage readings, etc...

 

Remember, wiring is a prime candidate for tolerance stacking; bad connection here, an extra ohm or two there, can add up to one big electrical gremlin headache. I'm thinking you're looking at more than one issue here....

[DailyDato]

Thanks everyone,

 

Yello620 - Yes, both issues in my other two posts have been repaired, the issues with the residual voltage on the fuse box was from what is called in the schematic, Full Transitor Amp, removed it and its corresponding wires, and its fixed, and the mix up with which wire is the harness ground and hot wires, I simply cut the harness open and traced the ground from my core support over th the battery.

 

When my truck was still 100% stock, the issues first began with the BW wire that runs from the ignition switch, to the fuse block, and to the coil, the wire was burnt nearly two inches off the key, and where it makes the connection between the engine bay harness and the dash harness was also melted, and the PO had jumped the red wire for the fuel cut solenoid to the ele. choke, because the red wire off the coil BW wire was no longer functional from the splice at the core support. I replaced the entire wire, and no other issue, truck ran great.

 

I then began removing everything I didnt want/need, the L20 4 speed came out, and all i have left, is all exterior lights, horn, and both relays, for the interior, I have the guage cluster(with temp guage yellow/white wire cut short n taped), after market sunpro tach, blower motor, cig lighter (not hooked up), wiper motor, and column switches, and an un hooked interior lamp, two extra lights for my oil pressure and temp guages from sunpro. I dont even have a stereo wired in yet. The entire harness was removed, untaped, clipped, soldered, and heat shrunk, and rewrapped, I then wired in a 94 DE harness, to the specs of How to wire a KA/CA/SR....page, and everything is wired on its own fuse block with power provided with 80A fuse on 4ga wire, and then the only other splices in the stock truck harness were made at the key with ?16ga? to operate my relays, everything else is its own power and ground source. even the DE harness has been reworked and tucked, and all the extras removed.

 

Everything was perfect and fine, until the yellow wire came off my blower box, and shorted out to ground, and now my blower switch no longer works on low, and it blew fuses, cant remember which ones now, except it blew the 80A fuse for the engine too, and i know it has nothing to do with it, but it did, and how do i know it was only the yellow wire shorted, it was dark, my dash has no pad on it, and i watched it spark while driving. the only other weird short and fuse blowing that i didnt accidentaly cause was when the hazard flasher came loose swung down an smacked the back of the fuse box and popped two or three.

 

As for wires melting, after the PO "attempted" to repair the orginal harness, I had to repair the BW wire off the key, I have now had to repair the W wire, and the BR wire off the key, I have even replaced the key as well thinking it was cross shorting or something, nothing else has gone wrong in several months now, BUT.......

 

In the diagram, there is a B wire that goes from the battery to the IR alternator, and is the Giant wire in the passanger corner of the cab that has the giant blade terminal on it, it then runs across the dash, and makes a splice to the RY wire that goes into the inline glass fuse there under the dash after that splice, the B wire feeds the blower power, the key, and the fuse box. Which is the horn, the lights, and i would assume the running lights, the white wire off the key is spliced to the B wire, the W wire feeds power through the switch the the L wire, and it runs to the cig lighter and radio. The RY wire that is spliced off the B wire, feeds interior lights, cig lighter, and tach power. I have nothing added to the B wire except less than factory...... The wire melts after the blade terminal and before the RY wire, Any idea why? and it typically, yes typically, it doesnt do it all the time, making me think its a short, but i can, and have replace the entire wire, larger, smaller, doesnt matter, it gets really really hot, and the insulation begins to shrivel and sag like its melting, but its only in the dash harness, and it happens when there is full load on the wire, headlights on high or low, wipers running high or low, blower on high, and it wont do it...... kick on a turnsignal and hold the brake........and give it a minute, it will happen, I have rechecked everything, ohmed every wire, cleaned every ground, cleaned every switch i could disassemble, all new relays, which is only the headlight relay, horns dont work, and the only other relays i added are bosch 5 pins three for the ECM and one for the fans.... thats it, but the ECM and the fans, are not connected to the B wire.....

 

So mainly I ask, is why does this wire melt, and why it it always in the same place? I have even removed the blade terminal, and made it a solid wire, several times. If it is a short to ground, Why does everything work, and why does it burn the biggest wire in the harness and not the lil small simple ones? I figured a smaller wire would get hotter quicker than the big one.

 

but on a good note, no more fuses are blowing, i have worked four days and most of the nights to rack my brain, and its down to the one wire now WTF?

[yello620]

 

 

In the diagram, there is a B wire that goes from the battery to the IR alternator, and is the Giant wire in the passanger corner of the cab that has the giant blade terminal on it, it then runs across the dash, and makes a splice to the RY wire that goes into the inline glass fuse there under the dash after that splice, the B wire feeds the blower power, the key, and the fuse box. Which is the horn, the lights, and i would assume the running lights, the white wire off the key is spliced to the B wire, the W wire feeds power through the switch the the L wire, and it runs to the CIG lighter and radio. The RY wire that is spliced off the B wire, feeds interior lights, CIG lighter, and tach power. I have nothing added to the B wire except less than factory...... The wire melts after the blade terminal and before the RY wire,

 

Damn Daly, gotta give you credit for taking the time to write details. :cool: Rather than the vague one sentence crap that we seen to be getting lately for people.

 

 

I sounds like you have it narrowed down quite a bit. Few things, (1)do you have two CIG lighters?? (2)And that B wire should not be feeding the heater blower motor either(it does go to another subharness and fuse on air conditioned trucks).. And third is, remember that everything on that wire is getting battery power at all times, so make sure all those items that are disconnected(cig, radio, dome light) are taped so as not to make contact to ground. I would first suspect the dome light because it is routed into areas that are unseen and you would not see the sparks either.

[DailyDato]

Thanks Yello, I have this diagram stuck in my brain at the moment, I only have one cig lighter, its power supply has the lil rubber coating on it, it wont short, but its taped as well, the radio wires are non exsistant, dome light wires are zip tied up and put away until i get my new door switches..

 

I understand that the B wire does not feed the blower, its the BW, but.... heres what i have done, every switch that can be opened, cleaned and reassembled, steering column included, done, every connector one wire at as time has been removed, cleaned, and re pinned, as well as to insure that the terminals fit together sungly and securly, every bulb socket disassembled, cleaned and reassembled, new headlight relay, new bosch relays to the DE swap and cooling fans, new turn flasher, hazard flasher, douched the fuse block, new glass fuses, new fuses in the accessory fuse block, every bulb/connector has been packed with dielectric grease, 10ga grounds ran through the complete harness, overkill? maybe, do i care, certainly not when it comes to grounds, The B wire from the battery to the fuse block, is now 10ga as well...........

 

Maybe anyone can answer this one, but if my / your truck is wired absolutly and completely exactly by the way the FSM says it should be, if you turn on everything you can in your truck, engine running without interior lights, a radio, or the cig lighter functioning, Does the blower motor on high or low surge with the turn signal/ hazard flashes, as well as does the opposite tail lamp dim as the turn signal applied flashes, either direction? with no affect to the front turn signals? and then finally, if the said vehicle does this, Does the B wire from your battery to your fuse block, get either extremly hot, coating melt off, or smoke if left in operation long enough. BTW headlights on, and no brake lights and wipers running......this is what is happening to me, and nothing, nothing im doing is solving it, and as of today, brand new 90amp alternator..........my brain hurts

[DailyDato]

i even increased the fuses by 5 amps each, no noticable change

[Guest kamakazi620]

i even increased the fuses by 5 amps each, no noticable change

NO!!!!!!!!!! DO NOT do THAT!!!!!!!!! you WILL fry your wiring and everything else!!!!! NEVER put Bigger than the rated fuses!!!!!!

[yello620]

Yes, i have seen the dimming light issues before without the wires getting hot. But i have only seen it with stock or close to stock alternator output ratings.

 

I too dont like the idea of the larger fuses.

 

What did you lube the ignition switch with??

[]2eDeYe]

What amperage is your alternator?

[Guest kamakazi620]

Bad connection in turnsignal switch???? its in the headlight circuit

[DailyDato]

Yello620 - Ignition switch was replaced with a new one but connection wass lubed with dielectric grease

 

]2eDeYe - i believe the new alternator is rated at 90 amps

 

kamakazi620 - i disassembled the turnsignal and head light switcha assembly, used a points file to clean everything up, and lubed it with dielectric grease, and ohmed all connections over the complete harness and recieved little to no resistance, but no open circuits, shorts, or high resistance has been found yet.

 

and i only swaped the fuses to 5amps higher to see if it would either prevent the surge, or smoke a wire some where other than a 10ga i would have thought that the smaller component wires would burn closer to the issue, but nope, its always in the same spot, new wire old wire, bigger wire, smaller, dont matter, and it can be in there five minutes, it will smoke, melt, w.e.

[]2eDeYe]

Does the B wire from your battery to your fuse block, get either extremly hot, coating melt off, or smoke if left in operation long enough.

 

There should be a fusible link here a few inches away from the battery. Last time I burn one up was from turning the starter for way too long and double clicking the starter as well. I had moment that day as I had left the lights on and was flustered while getting a jump.

 

Have you check to see what kind of amps you are pulling as you turn on each system?

[DailyDato]

There was a fusible link at one time, i fired it tho, and put several more in place, but at the current moment, no, there is not, i replaced the entire B wire with a new 10ga wire, straight from the battery to the fuse box

[DailyDato]

Ok, well this is where things get weird, found the Issue, any one got a known good blower motor that will fit my 620? The blower is back feeding voltage in the harness, that and the ground to my tail lights was very weak, it ifxed the dimming side to side with the flashers, but yea, all is well again.....for now. Lets see how long this lasts