78 f150 new alternator, voltage reg., wiring still won't charge
#1
03-21-2014, 02:42 PM
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78 f150 new alternator, voltage reg., wiring still won't charge
Hello I have a 78 f150 302 4x4 4 speed. I have had the truck 4 years, about 4 months ago the old 55 amp alternator died, I replaced it with a 70 amp along with a voltage regulator. One night the key was left on, when I got up the next day it was completely dead, so I charged the battery hooked it back up an the solenoid hung. I replaced the solenoid an go it going, couple nights later the key was left on again, charged the battery seemed to be no damage. Ran it for an hour an the battery died, hasn't charged since, I warrantied alternator an voltage regulator twice, I found the red/blue wire that runs from the solenoid to the "clutch switch" was burnt up along with a couple other wires(the switch was bypassed so I cut the plug off an ran the red/blue straight through to ignition switch I believe. I have bypassed the one resistor wire I found under the dash, checked the fuse block, cleaned and checked all wiring an it still won't give me charge. I can run power to f terminal on voltage regulator an it draws down on motor a little bit but the numbers I get at the battery fluctuate between 12.5-13.1 with jump wire to f on volt. Reg. I have some dash light issues but have 2 clusters an have tried both. So if anyone has any ideas or advice please feel free! I'm at my witts end with this old truck. Its been on the road maybe 2 months out of the years I've owned it. Thanks, Kyle
#2
03-21-2014, 02:55 PM
#3
03-21-2014, 02:57 PM
What was the purpose of this? The charging system does not use any resistor wires. This just adds variables and is going to cause other problems depending on what you did specifically (if you bypassed the ballast resistor, you'll eventually fry the coil and ignition module).
None of the charging system passes through the fuse panel.
Why do you believe the instrument cluster to be part of the story? Is there something you're leaving out?
#4
03-21-2014, 04:14 PM
kyle78f150 welcome to FTE, yea a bit of a rough welcome, but you got mucho elec issues and are already being assisted by the best spark chaser/electricial engineer on FTE bar none!
1. Quite leaving the key on...taking it out of the ing wil prevent that.
2. Just answer fmc400's questions and he will get it figured out. Just follow his advice to the letter, and anything you do not understand just ask, no matter what, ASK.
Be very detailed on your issues and test results, he will help you.
Again welcome.
1. Quite leaving the key on...taking it out of the ing wil prevent that.
2. Just answer fmc400's questions and he will get it figured out. Just follow his advice to the letter, and anything you do not understand just ask, no matter what, ASK.
Be very detailed on your issues and test results, he will help you.
Again welcome.
#5
03-21-2014, 04:18 PM
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Okay, there's obviously more to the story here. Why would this wire have been burnt up? What are you not telling us? And what are the "couple other wires" that were burnt up, why did it happen, and what specifically have you done?
......
The other couple wires that had burn spots in them ran to the same clutch switch plug, 2 white with stripe,2 black, my wiring diagram shows them going to reverse lights. I had not done anything to the system besides leave key on an change starter Sol. It was previous owners who removed switch an just looped wire in plug.
What was the purpose of this? The charging system does not use any resistor wires. This just adds variables and is going to cause other problems depending on what you did specifically (if you bypassed the ballast resistor, you'll eventually fry the coil and ignition module)......it was not ballast resistor, it was a resistor wire ran from a black an yellow that runs to ign switch and instrument cluster plug. I have put resistor back in. No improvement either way.
None of the charging system passes through the fuse panel.
It was something said by one of the idiots at the parts house that made me check resistor wire and fuse block
Do you hear the alternator spin up or whine at all? Are you sure the batteries in your meter are good?
Yes I can hear the alternator whine. And batteries in meter are fresh.
Why do you believe the instrument cluster to be part of the story? Is there something you're leaving out?......
......
The other couple wires that had burn spots in them ran to the same clutch switch plug, 2 white with stripe,2 black, my wiring diagram shows them going to reverse lights. I had not done anything to the system besides leave key on an change starter Sol. It was previous owners who removed switch an just looped wire in plug.
What was the purpose of this? The charging system does not use any resistor wires. This just adds variables and is going to cause other problems depending on what you did specifically (if you bypassed the ballast resistor, you'll eventually fry the coil and ignition module)......it was not ballast resistor, it was a resistor wire ran from a black an yellow that runs to ign switch and instrument cluster plug. I have put resistor back in. No improvement either way.
None of the charging system passes through the fuse panel.
It was something said by one of the idiots at the parts house that made me check resistor wire and fuse block
Do you hear the alternator spin up or whine at all? Are you sure the batteries in your meter are good?
Yes I can hear the alternator whine. And batteries in meter are fresh.
Why do you believe the instrument cluster to be part of the story? Is there something you're leaving out?......
#6
03-21-2014, 05:04 PM
#7
03-21-2014, 05:11 PM
Please answer the rest of my questions; we're not any farther along than the first time you posted.
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#8
03-21-2014, 05:45 PM
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the other couple wires that had burn spots in them ran to the same clutch plug, 2 white with stripe, 2 black, I had not done anything to the system besides leave the key on an change starter sol. ity was previous owner who removed clutch switch an just looped wire in plug.
it was not ballast resistor it was a resistor wire tied in to black/yellow ran to ignition and instrument cluster........I have put new resistor wire in, no improvement either way.
it was something said by one of the parts house guys that made me check the resistor and fuse block.
I can hear alternator whine and have new batteries an 2 test meters.
as far as the actual battery in the truck I have tried 2 different batteries, the one that's in it I bought new less than a year ago an the other is my known good Cherokee battery 2 months old.. I will try to answer any questions best as possible sorry for the delay, it only showed the bottom portion of my reply earlier.. and as far as leaving the key on, I have taken them out of the truck an have been keeping the doors locked so the neighbors kids cant "play" in it anymore.
it was not ballast resistor it was a resistor wire tied in to black/yellow ran to ignition and instrument cluster........I have put new resistor wire in, no improvement either way.
it was something said by one of the parts house guys that made me check the resistor and fuse block.
I can hear alternator whine and have new batteries an 2 test meters.
as far as the actual battery in the truck I have tried 2 different batteries, the one that's in it I bought new less than a year ago an the other is my known good Cherokee battery 2 months old.. I will try to answer any questions best as possible sorry for the delay, it only showed the bottom portion of my reply earlier.. and as far as leaving the key on, I have taken them out of the truck an have been keeping the doors locked so the neighbors kids cant "play" in it anymore.
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03-21-2014, 06:13 PM
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and the story on the truck is i bought it with an 85 302 in it, it cracked the block within a month (i guess someone had dropped a nut or bolt down the carb). i put a 74 302 out of a torino i think, in it. Along with the new motor i put a new distributor, ignition module, ignition switch, voltage regulator, starter, starter sol, intake and carb. i chased problems in the truck for the first couple years , it wound up bein the rebuilt carb had issues. but it ran well after that, i drove it to Boonville In from Nashville tn with no problems(never had charging problems before either) after leaving the key on i started finding the rigging while removing electrical tape trying to find out why it had killed the battery after a 15 mile trip to the dump with the heat on this winter.
#11
03-22-2014, 08:28 AM
I see you cross-posted this same thread in the Electrical forum and you've already tried all this. Assuming that's so, check the continuity of the wire from the 'F' output of the regulator to the FLD input of the alternator. That being bad would be another reason that jumping the 'F' terminal doesn't make the voltage across the posts jump. However, that doesn't really jive with the fact that you hear the alternator spin up (which is a GOOD sign).
#12
03-22-2014, 12:19 PM
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That's an 8.5-ohm resistor wire to power the instrument cluster voltage regulator for the gauges. It has nothing to do with the charging system.
Your results thus far indicate that the alternator is charging, but you don't see a proper charging voltage across the battery posts with a known-good meter. With the F terminal of the regulator jumped, the regulator isn't even part of the picture. All of this indicates that the fusible link at the output of the alternator is open or on the verge of failure as alluded to in the above post. You can check its resistance with your multimeter. You may see an intermittent or false reading since there appears to be at least some continuity through it, as indicated by the fluctuating voltage across the posts with the regulator jumped. If it looks worn or tattered, you may want to just replace it regardless.
I see you cross-posted this same thread in the Electrical forum and you've already tried all this. Assuming that's so, check the continuity of the wire from the 'F' output of the regulator to the FLD input of the alternator. That being bad would be another reason that jumping the 'F' terminal doesn't make the voltage across the posts jump. However, that doesn't really jive with the fact that you hear the alternator spin up (which is a GOOD sign).
Your results thus far indicate that the alternator is charging, but you don't see a proper charging voltage across the battery posts with a known-good meter. With the F terminal of the regulator jumped, the regulator isn't even part of the picture. All of this indicates that the fusible link at the output of the alternator is open or on the verge of failure as alluded to in the above post. You can check its resistance with your multimeter. You may see an intermittent or false reading since there appears to be at least some continuity through it, as indicated by the fluctuating voltage across the posts with the regulator jumped. If it looks worn or tattered, you may want to just replace it regardless.
I see you cross-posted this same thread in the Electrical forum and you've already tried all this. Assuming that's so, check the continuity of the wire from the 'F' output of the regulator to the FLD input of the alternator. That being bad would be another reason that jumping the 'F' terminal doesn't make the voltage across the posts jump. However, that doesn't really jive with the fact that you hear the alternator spin up (which is a GOOD sign).
I'm getting 0.2 resistance from f on regulator to fld on alternator. What size fuse should be in the fusible link? I put dash back together last night all lights are working besides alternator dummy light.
#13
03-22-2014, 12:26 PM
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#14
03-22-2014, 12:57 PM
Post Fiend
A fusible link is rated as a gauge of wire instead of a fuse. I believe the size of fusible link wire is 16 gauge that you need. The wire section in any parts store should have fusible link wire. I'm not sure, but a regular fuse might just keep burning out. At least right now, the circuit is protected, but I would still add a fusible link section of wire and not the fuse.
#15
03-22-2014, 01:59 PM
I'm not sure what to tell you because you're giving conflicting observations. Something is not adding up; there has to be something else going on or something isn't getting communicated properly. If the alternator spins up and loads the engine, you should see the battery voltage climb. The only reason you wouldn't is if the battery is bad, or the fusible link is open. You've obviously tried a couple different batteries and verified in another thread that the fusible link is fine via the measurements you took. For whatever the reason, the scenario and events that I've interpreted as described to me over the internet are not what's happening in real life. Historically speaking, that's always the reason behind electrical problems described on the forum that make no sense.
As stated above, the fusible link itself is the fuse. Fusible links are sized two AWG steps below the wiring you're protecting (e.g, 14-AWG link for 10-AWG wire and 16-AWG link for 12-AWG wire).