my cars gauges go crazy when i turn on my lights and i cant even see my gauges at night.. also when i would have my radio on and id turn on the lights the radio would turn off and not come back on.. when i put the turn signals on my car my battery gauge and my rpm gauge go up and down with the turn signal i dont know whats going on i was told it could be a bad ground but who knows can someone plz help id appreciate the help thanks
Check the output voltage on your alternator. It may be letting you know it cant handle a load anymore.It should be 14.? volts. If your only getting 12 volts(battery voltage) output something is wrong.
Hi EDE,
What you have does sound like a bad ground. Here's what's happening. When you're just running your gauges you have a relatively low resistance to ground. There is a loose ground bolt somewhere but the minimal amound of current that the gauges are drawing doesn't significantly affect their operation. When you turn on the lights you now have to supply a ground for the gauges as well as all the dash lights, or if you're using the turn signal, the turn signal indicator light. Suddenly the marginal ground that was okay when you were using the gauges cannot handle the extra current from the light bulbs you're trying to power. It's like having a resistor in between the ground wire and chassis ground that increases it's value when the current through it goes up. You develop a substantial voltage across that "resistor" which can cause the problems you're experiencing.
The gauges may actually be effected too. They may be giving an incorrect reading but since the current isn't radically changing, everything looks normal.You just don't notice that the voltmeter is pointing at 13.5V when it should be at 14.2V. What you do notice is the instant change in gauge readings as soon as you turn on the lights or turn the signal. The gauges seem to pulse, changing their indicated values, as the turn signal, (or lights) turn on or off.
This sounds like a bad ground problem. What you need to look for is a ground wire with an eyelet. There's a bolt through the eyelet that has loosened. Tightening the bolt with a socket or wrench should fix the problem. You just need to find the bolt.
Start looking under the dash. Take out the panel, if there is one, under the steering column and look around the steering column mounting bracket. Look near the firewall. If you don't find it there, look on the passengers side. Look under the hood by the firewall, or on the fenders. These are places that you can typically find the ground. Also, there may be more than one wire in the eyelet. It may be a junction of 2 or more wires sharing the same eyelet. Let us know what you find.
Hope this helps,
David
This problem sounds like a classic:
Just like someone did the valve cover gaskets, and didn't put back on the two ground straps from the firewall to the valve cover bolts.
Look there first, then look under the dash at the driver's side, there is a metal bracket that holds in the instrument cluster in the plastic part of the dashboard, and also a few screws that penetrate the metal bulkhead, that holds the brake/clutch pedal, if the car is manual transmission. So a loose dash trim screw may be the culprit.
If you have replaced your stock radio for an aftermarket, make sure that you didn't short the black wire from the radio plug, it's a long shot, but can cause the same problems on an unfused install.
Refinish King
my car is a manual transmission and i had put an after market radio on my car but i took it off because of the problems when i turn on my lights so um what is the certain screw that i need to tighten or what.. thanks EDE
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