No power at all! No lights, nothing. With the key OFF, I've got 12v at the battery, cable, solenoid all the way up to a buss bar under the cowl which powers all my relays, gauges, etc. With the key ON, I've got 12v at the battery but, only 1v at the cable which is attached to the batt post! 1v all the way up the line to the buss bar. This is only with the key ON. In addition, I was playing around taking readings and such when suddenly I noticed I had 12v to the cable with the key on! Walked around, turned it to start and it fired up. Lights worked and everything. Turned it off and it went back to 1v. WTH! My electrical skills are basic. Does anyone have any insight?
sounds like a bad or dirty terminal. There's a reason it behaves that way...when there is no load (switch on), you get voltage. When there is a load, the voltage goes away, because of the resistance in the terminal.
Take both terminals off the battery and scrape the inside of the terminal with an exacto knife, do the same with battery posts.
yeah, no load, sorry! when there is a load, the voltage goes away, because of the resistance in the battery terminal.
How old is the battery? Do you have another battery you can try, to see if your battery is the problem?
Yeah, terminals probably need cleaning. One of these is handy to have in the glove box: They're like $3 at the parts houses or Harbor Freight. Also, those felt washers for the terminal posts work well for keeping down corrosion. Plus IMHO they look good. A nice little added detail.
Connections. Grounds, fusible link which is often a section of wire in the loom. Good luck finding the problem
Well, looks like squirrel nailed it! Bought a new Pos batt cable (it needed one anyway), cleaned the terminals really well and the roadster fired right up! Big weight off my shoulders. I thought there may be a short in the wiring somewhere and I would have to pull the cowl to access the harness. Everything seems to be working fine! Now I can get back to the '54 build! Thanks squirrel and everyone who chimed in! HAMB to the rescue....again!
If the positive battery terminal was bad, I think I would look at the condition of the negative terminal as well, it may not be much better. Gene
You just did a voltage drop test, probably the best overall electrical test. You were dropping 11 volts due to a dirty battery cable. Voltage drop tests only work when there is a load on the circuit. In your case, turning the ignition on loaded the circuit and you found the bad connection. It also works on the ground side which many mechanics forget.
Man, brings back memories! My Dad had 6 volt vehicles. Any time there was an issue : Clean your connections 1st! You can't expect anything electrical to work with corroded connections. Sent from my LG-TP450 using The H.A.M.B. mobile app
Think of the flow of electric like the flow of water. When you get a kink in the hose (a bad connection) some of the electrons will flow, enough to get a meter to resister but not enough to turn a starter motor. So just because that meter shows voltage doesn't really mean anything. Go over all the connections with WD-40 and make sure they are tight. Look for corrosion, it could be under the insolation of the wire..
The Jalopy Journal
