Voltage Drain?
Thread Starter
Melting Slicks
Joined: Mar 2003
Posts: 2,898
Likes: 0
From: Oklahoma City Oklahoma
Voltage Drain?
OK, here's a brain twister for y'all.
When the car is running with no accessories on, the digital dash works great, but turn on the lights, or the AC/Heater, or signal lights, in fact just about anything, and the fun begins.
1. Oil pressure reading drops dramaticly.
2. Engine temp reading rises dramaticly.
3. Low voltage warning comes on.
4. Low oil pressure warning comes on.
I've had everything above checked with manual gauges, and all is well.
Have had new alternator installed....no change
Installed a new battery with a new ground strap....no change.
Instrument cluster has been rebuilt...no change.
Serpentine belt is good and tight.
I'm getting used to this nonsense now, and I know that all systems are functioning properly, in spite of what the gauges say, but it is getting annoying.
If anyone out there in tech land has any ideas, suggestions, cures, etc. I sure would appreciate any help thrown my way. Thanks in advance!
Larry
When the car is running with no accessories on, the digital dash works great, but turn on the lights, or the AC/Heater, or signal lights, in fact just about anything, and the fun begins.
1. Oil pressure reading drops dramaticly.
2. Engine temp reading rises dramaticly.
3. Low voltage warning comes on.
4. Low oil pressure warning comes on.
I've had everything above checked with manual gauges, and all is well.
Have had new alternator installed....no change
Installed a new battery with a new ground strap....no change.
Instrument cluster has been rebuilt...no change.
Serpentine belt is good and tight.
I'm getting used to this nonsense now, and I know that all systems are functioning properly, in spite of what the gauges say, but it is getting annoying.
If anyone out there in tech land has any ideas, suggestions, cures, etc. I sure would appreciate any help thrown my way. Thanks in advance!
Larry
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
Re: Voltage Drain? (White85InOKC)
Almost all of the electrical devices receive current through the ignition switch contacts. You have ign sw contacts with excessive resistance causing low voltage on just about everything in the cockpit. Normally the ign sw has about 0.3 volts drop across its connection resistance. You can check this by measuring the voltage across the battery terminals and comparing it to the dash voltmeter. I am sure you will find that the battery terminal voltage stays constant , while the dash voltmeter drops (you already said it does) when you turn on something. You need a new ignition switch.
Pro
Joined: Jul 2002
Posts: 729
Likes: 4
From: Yukon OK
Re: Voltage Drain? (White85InOKC)
Larry;
I still think the belt maybe an issue. The spring tensioner looked like it was near the end of it's travel. How old is the belt? Could be slipping even if it is tight. I ended up putting a slightly shorter belt on mine that got the tension back in spec. I can give you the size if you want it.
I still think the belt maybe an issue. The spring tensioner looked like it was near the end of it's travel. How old is the belt? Could be slipping even if it is tight. I ended up putting a slightly shorter belt on mine that got the tension back in spec. I can give you the size if you want it.
