I checked the battery with my meter, showed 12.5V. Not running. Then I checked the hot at the switch on the console and it was 11.4V. I looked in my repair manual at the schematic and did not see a ballast resistor in that line. If there is not a ballast resistor shouldn't I get the same voltage as the battery. A friend of mine ran a hot from the battery to the switch. He did this to ensure himself he was getting a true 12v at the key. Should I do the same???????
If you have a stock, 12 or 10 gauge wire to the dash...it will have resistance in it (since it's pretty long). That cheezy stock wiring probably also has to support all you accessories wired at the dash, too.
If you replace it with at least 8 gauge, you should have less voltage drop. Don't forget to replace the ground while your at it.
I checked the battery with my meter, showed 12.5V. Not running. Then I checked the hot at the switch on the console and it was 11.4V. I looked in my repair manual at the schematic and did not see a ballast resistor in that line. If there is not a ballast resistor shouldn't I get the same voltage as the battery. A friend of mine ran a hot from the battery to the switch. He did this to ensure himself he was getting a true 12v at the key. Should I do the same???????
You obviously have a "voltage drop". You need to take your voltmeter and start checking v/drops between the battery positive and EACH connection/section in the circuit between the battery and the ignition switch. You should have the key in the run position when you do this. This way you can find the exact area of resistance. You should use the same procedure on the ground side. Be sure to check the drop across the ammeter, if you have one. I agree that a #8 feed wire would be good, but you should locate the source of your problem. Hope this helps.
Dave
Thanks,
I was planning on running both. The ground comes from the block. I'd rather have a ground come all the way from the battery. I'm an electrician. I've of ten wondered what the difference is in automotive type electrical wite and industrial wire. I was going to use like a #10 THWN . Its stranded and rated at 30 Amp A/C.
Maxy,
I'm not sure I totally follow how to do this. I would think I would connect the voltmeter to a good ground, preferably the battery. Check the volts across the battery, then go to each connection and read the voltage. If it differs then I have a volatage drop. For example, If I have a 12V at the battery, I then checx where the hot wire ties in to starter it is 11.5, I need to replace that cable. I know your going to have some drop. In AC 4% is acceptable, if I'm not mistaken. How much is acceptable in DC. Also, This voltage drop I have at the swith could this be why it doesn't just "fire up" when i try to crank it. My buddies, you just bump the starter and its running. Yes, I know there are alot of other reasons why it doesn't just "bust off". But could this be some of the problem?
I'm running a Thunderbolt IV. I thought a fully charged battery would be about 12.6
Obnoxious,
Are you taking the reading with the engine running?
13.7 looks more like a voltage while running.
I am usually at about 12.6 off and 13.6 =/- while running.
J
Thats where I'm at. My original question was what should it be at the switch, not running. And how much voltage drop is acceptable before it starts affecting how the motor starts.
Thanks,
I was planning on running both. The ground comes from the block. I'd rather have a ground come all the way from the battery. I'm an electrician. I've of ten wondered what the difference is in automotive type electrical wite and industrial wire. I was going to use like a #10 THWN . Its stranded and rated at 30 Amp A/C.
Get automotive/marine rated wire. The insullation is meant to withstand exposure to UV and oil. In addition, the biggest difference is the number of strands of wire. DON'T USE HOUSE WIRING, vibration will kill (break) the few heavy strands that they have.
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