[GUITAR1989]

Hey guys Ive been having some electrical componants mess up on me and im wondering if you guys might be able to help me sort it out. The truck is a 1974 Chevrolet C10. It has a new carbureted Vortec 5.7 that I just swapped in so all wiring to the engine has been moved to the new engine and an oil pressure safety switch was added. it has hei, starter, oil pressure safety switch, electric choke, water temp...thata all the engine wiring i think.

The other day I went to crank my engine over and the starter just clicked. I had fully charged the battery and the starter worked fine on my old engine and seemed to be working ok on this one. Maybe kinda sluggish when cranking the engine over but i just figured it was cause it didnt have shimms yet or possibly cause of the higher compression. Tried to jump power from the starter batt terminal to the one that starts it but it still just clicked.

I figured the starter just crapped out at that point and I was going to buy a new one. Well the next day I was listening to music while working on my truck and one of the speakers just got major distortion so i figured it was messed up and i put all the sound through the other speaker.....Then today I was listening to the radio in the truck. My nephew came up to me so I turned the volume down and when I went to turn it back up my other speaker wasnt working then the head unit started going off and on.

Does anybody have any suggestions as to what i should check What should I be looking for that could cause this?

I have pretty detailed pics of my truck so if you need to see how something is wired i can show you pictures

[1971BB427]

First thing I'd check is the volt meter, and if you don't have one I'd get one! You need to know what the voltage is when the engine is running. It sounds like you may have alternator/regulator issues, and it may be overcharging and taking out electronic components.
Once you've got a meter or gauge on it, start the engine and see if voltage is over 14 volts. Ideally it will be 13-14 v. and if it's higher you've got either a bad regulator, or alternator.
Rarely will a battery cause a high voltage problem. It's almost always the charging circuit components.

[GUITAR1989]

I actually cant start the truck cause my starter doesnt do anything at all now. my batt is at 11.## volts with key in off position but when i put the key in the on position voltage drops fast to like 6 volts I havent tried to crank yet since my oil pressure gauge isnt connected and my wiring would get an oil bath if i cranked the engine over. when i turn it off the battery voltage slowly climbs back up. To be honest the wiring in my truck was a nightmare when i got it. right after i bought the truck i replaced a melted headlight switch wire that melted into quite a bit of the cab wiring harness. I took out old lighting and cigg lighter wiring today. I also found out that my ground for my gauge lighting and stereo was a horribly rusted connection and an old brittle wire so i replaced it and bolted the ground to some sheet metal.
Im going to keep going through the wiring and cleaning up the old corroded stuff but i also am going to draw a diagram of my engine wiring just to make sure i did it right. I added a few new things durring the engine swap so i wanna make sure i didnt wire something up to a wrong post. I added an Electric Fuel Pump, Oil Pressure Safety Switch, mallory HEI.

I read if you have an hei you dont use all starter wire terminals but my starter has all 3 terminals with wires on them.

Also I need to make sure my oil pressure safety switch is wired in right along with the electric fuel pump.

I hate wiring

[curtis73]

Originally Posted by GUITAR1989

. my batt is at 11.## volts with key in off position but when i put the key in the on position voltage drops fast to like 6 volts

Sounds like you either have a massive draw (unlikely) or the battery is shorted. A good battery should read 12.4v or higher alone, and stay well above 12v for quite a while with the key on.

A few things to try:

1 - disconnect the negative terminal. Use a multimeter to measure the amperage between the disconnected cable and the negative post. Do the same with the key on and off. If you have anything more than .25 amps, you have a drain.

2 - disconnect the negative and put the battery on a charger overnight. If you test it in the morning and its below 12v, the battery is toast.

3 - If you have more than .25 amps after trying #1, leave the meter in place and pull and replace fuses one by one. If (for example) you pull the "wiper" fuse and the amperage drops significantly, you have narrowed your problem down to anything on that circuit. MUCH easier than guessing.

4 - use a known good battery and try to start it. If it doesn't start, suspect the starter. If it does start, test voltage while running. If its not above 14v, you may have a bad alternator.

[1971BB427]

Still sounds like it might be charging issues, but it also sounds like you've got tons of other wiring cocerns!
The 3 wires on the starter are the main battery, and the start signal, plus the idiot light or volt meter. All three wires will be used regardless of which distributor you have, as the extra wire is going back to the alternator, or regulator to sense voltage drop.
If by chance your battery had an open cell it can and will often take out your regulator, alternator, or both. But if the same components go bad a high charge rate will take out the battery too, so no way to know which is the cause. It's best to pull your alternator and battery, and have them both tested to see which might be bad, or if both are bad.
Get all the wiring cleaned up, safe, and properly hooked up before replacing any defective components.

[GUITAR1989]

Hey guys So I pulled out my dash and cleaned up the wiring quite a bit. I got rid of alot of old accessory and interior light wiring. The old lighting was pretty much gutted aside from a light under the dash that would occasionally come on. Interior lighting, cig lighter, gauges and stereo wiring..This was all ground to the same horrible corroded wire that was grounded to the rusty parking brake I replaced the ground wires and ran them to a nice clean body ground. I also charged the battery.

Fired right up!!! Voltage doesnt seem to be dropping but Ill have to keep a close eye on it. Voltage is also stable and doesnt fluctuate on any fuse block fuses or terminals. Now Im going to look into what wiring I need to get rid of that use to power the old points distributor. The guy who owned the truck before me installed an HEI but just plugged it into the points wiring. Ive seen a few threads on here about it ill check em out

You dont know how happy I was today when my starter actually cranked over and she fired right up

[EOD Guy]

Starter wiring....... "S" terminal is the energizer wire to engage the soleniod and make the starter motor spin. The "I" terminal is the "hot in start" wire that provides a full 12v to the coil with the old points system and is not needed with an HEI dizzy. The old wire to the points dizzy only had 9ish volts going to it when the key was in the run position, you need to make sure that wire has a full 12 volts in run and start positions. If it has 9ish volts you need to run a new wire from the dizzy to where the old resistance wire hooked into the ing switch and do away with the old resistance wire. If the new wire isn't providing 12v when the key is in the crank position..... simply route the wire from the "I" terminal on the starter and splice it in at the dizzy. BTW never heard of a wire from the starter going to the voltmeter or idiot light..... unless it was connected to the large battery feed terminal