67 k20 electrical problem.. help?

[Nick Goldsmith]

hi. I have a 67 k20 dump with what I think is an early eightys 250? last week it would not start which was unusual as I had used it a few days earlier. I charged it for awhile and then jumped it. It idled up to 190f but I had no power and could not rev the engine. I thought maybe the choke was stuck so with the engine still running I took off the air filter to check that. I just turned to put the air filter in the garage when there was a big flash and the battery blew up.

1. battery was dead after only sitting a few days.
2. charged battery w/ 10amp charger.
3. jupstarted.
4 idleing with no power.
5. battery blew up.


Chapter 2.
1.turned it over with no battery and jumper cables. juice went to distributer but no spark.
2. went to auto zone for free replacement battery. had alternater tested. tested good for charge and regulater.
3. bought new HEI distributer cap,rotor,coil and wires.
4. Put it all back togethr. no spark.
5. new condenser. no spark
6. new control module. fired up on first turn. let it warm up and drive arround the neghborhood for half an hour. Good power, less backfireing,sounds much better but kills battery. Not chargeing.
7. I notice that my clearance lights are melted. the clearance lights are on the same circuit that feeds the alternator. I test the feed from ignition to the alternator and it has no juice.
8. I assume the reason I am not charging now is because there is no juice going to the alternator?

My question now is why did my battery blow up and will it blow up again? I am kind of gun shy working under the hood with the battery connected right now! my theorys are...
1. the clearance lights short out killing the feed to the alternator causeing the dead battery? The battery blows up from chargeing and jumping ?
2. the battery blows up from some kind of feed back from the bad distributer while it is stressed out from jumping?.

3. The battery leaked a little on top(fact). the 30+ year old ignition wires threw a spark, battery blows up frying clearance lights and control module?

my best guess is the short happened first wihch is what resulted in the dead battery on day one. fairly clueless on what made it blow? What do I have to do to not get blown up again?
Thanks much for any help.
Nick

[VetteVet]

.........

Originally Posted by Nick Goldsmith

hi. I have a 67 k20 dump with what I think is an early eightys 250? last week it would not start which was unusual as I had used it a few days earlier. I charged it for awhile and then jumped it. It idled up to 190f but I had no power and could not rev the engine. I thought maybe the choke was stuck so with the engine still running I took off the air filter to check that. I just turned to put the air filter in the garage when there was a big flash and the battery blew up.

1. battery was dead after only sitting a few days.
You have a drain on the battery drawing juice slowly. It could be several things. Regulator, alternator, a light on, radio, key switch, horn relay, etc.

2. charged battery w/ 10amp charger.
Did you charge the battery slowly on 2 amps or on 10 amps.

3. jupstarted.
4 idleing with no power.

A low battery might not support a higher RPM spark especially if the alternator is not charging.

5. battery blew up.

A low battery emits gases while it is charging, these are explosive and a spark could cause it to explode.


Chapter 2.
1.turned it over with no battery and jumper cables. juice went to distributer but no spark.

Same thing, not enough juice to support a spark. An HEI distributor needs at least 10 volts to throw a spark.

2. went to auto zone for free replacement battery. had alternater tested. tested good for charge and regulater.

Do you have the stock external regulator and alternator or has it been converted to the internal regulated SI series?

3. bought new HEI distributer cap,rotor,coil and wires.

4. Put it all back togethr. no spark.
5. new condenser. no spark

What condenser, HEI does not use one?

6. new control module. fired up on first turn. let it warm up and drive arround the neghborhood for half an hour. Good power, less backfireing,sounds much better but kills battery. Not chargeing.

Correct it's just running on the battery which has enough charge to fire the ignition.

7. I notice that my clearance lights are melted. the clearance lights are on the same circuit that feeds the alternator. I test the feed from ignition to the alternator and it has no juice.

Are the lights just blown or are they melted or is the wiring melted, The clearance lights should not be on the same circuit as the alternator feed wire, unless you are talking about the large red wire that comes off the terminal on the back of the alternator.
The ignition does feed the alternator charging circuit from the key switch to the fuse panel and then to the dash for the charging light, if you have the idiot light instead of the seven gauge cluster. From there a brown wire runs to the firewall block and then to the voltage regulator if it's external.

8. I assume the reason I am not charging now is because there is no juice going to the alternator?

My question now is why did my battery blow up and will it blow up again? I am kind of gun shy working under the hood with the battery connected right now! my theorys are...
1. the clearance lights short out killing the feed to the alternator causeing the dead battery? The battery blows up from chargeing and jumping ?

2. the battery blows up from some kind of feed back from the bad distributer while it is stressed out from jumping?.

Not likely

3. The battery leaked a little on top(fact). the 30+ year old ignition wires threw a spark, battery blows up frying clearance lights and control module?

Possibly. Most likely the alternator was over charging and the excess voltage blew the lights and the distributor module.

my best guess is the short happened first wihch is what resulted in the dead battery on day one. fairly clueless on what made it blow? What do I have to do to not get blown up again?

If you got a short in the marker or clearance lights it should have blown the "stop/turn/tail fuse" in the fuse panel. A drain will not cause a blown fuse unless it is more amps than the fuse is rated for.
Get the charging system working properly, find the short or drain and charge the battery with the cables off and do not run the engine while charging with a portable charger.

Thanks much for any help.
Nick

[michael bustamante]

Is the hei dist a new addition or was the disributer swap out done previously? Did you bypass the extrrnal regulator or are you using the original style alternator

[special-K]

Disconnect the cab light wire and run a wire directly to the alternator. Get a voltmeter and check what's happening. A battery can also explode from overcharging. Do you smell rotten eggs?

[Nick Goldsmith]

the wireing is a god awfull mess. it's a farm truck. all I know about the clearance lights are that they used to come on the same on the same time as at the ingnition key is turned. same thing with my back up plow light though that would work if the key was turned the other way in acessory mode. I have not had a chance to check fuses etc yet. just got it running last night and then noticed that the clearance lights were melted as in the lenses got so hot they melted. then I figured out it is not chargeing.

it is a new style alternator that does not use the old regulator. i had the alternator tested @ auto zone and it tested good for charge and regulator