Question about 2002 GMC Sierra

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I am getting voltage drop itermittantly just when it gets really cold out. the lights go dimmer and you can hear the heater fan drop also

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Maybe you need a battery that has more cca.

Posted on Jan 04, 2013


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Posted on Jan 02, 2017


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1 Answer

How do I fix a voltage drop when applying breaks?

Get your battery checked. It sounds like you may have a faulty cell, or perhaps the alternator is not charging the battery properly.

Jan 14, 2016 | Kia Sedona Cars & Trucks

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Have no power to anything. The low beam relay under the hood clicks and the relay 13 under the dash clicks really fast.

Check the battery voltage and battery cable connections. It should be at 12.4 ~ 12.6 volts DC. Turn on a loads (radio, fan, lights) it should drop a bit but stay above 10 volts. Learn how to check he battery and alternator with the videos below.

Mar 23, 2015 | Cars & Trucks

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Car will not turn over, when lights first come on before trying to start they slowly get dimmer. Just makes a clicking sound,bought new battery in 2009. tested alt. at that time said it was fine. could it...

If your lights start getting dimmer when they first come on before trying to start, it is a very good indication that your battery is almost dead. You need to make sure your alternator belt is tight, then charge the battery fully, and then try starting it. If you have a tester, you can test the voltage, but to test it properly, you really need a battery load tester. 2009 is long enough back to warrant checking your alternator, again. What you can do is first charge the battery and try starting your car. If that works, your starter is fine. Then, with the car running, everything else turned off, check your battery voltage with a simple volt meter. Then turn on all the lights, heater, and anything else. Check the voltage, again. It should not drop, if your alternator is good. Leave the lights and accessories on for a while, then check the voltage again. If it has dropped, your alternator is not working properly. Get it fixed or replace it.

Feb 21, 2011 | 2004 Chevrolet Impala

1 Answer

91 honda accord battery lamp comes on, my climate is cold now and this seemed to begin when the cold started, after driving 20 minutes or so the lamp goes out, when the car is cold, if i rev the engine to...

Chances are, your alternator is on its way out. I had a similar issue a couple years back where the battery light was coming on in winter at startup but would turn off after a couple of minutes of driving. I know it was not charging the battery when the light was on because my head lamps and dashboard lights were a little dimmer than normal. I decided to just put a new one in instead of possibly getting **** in the cold somewhere. If I remember correctly, the voltage regulator is built into the alternator. I was tinkering with idea of pulling it out and trying to fix it, but it's really not worth it. Now, if you don't notice your lights being a little bit dimmer when the battery light is on like I did, the issue could be your battery. It should have 13.5 volts on it. Or you can just take it in to some auto parts store to have it tested. They usually do that for free.

Jan 05, 2011 | 1991 Honda Accord

1 Answer

No heat

You do not indicate if it is the fan not working, or if you are only getting cold air. If the fan, check the fuse first, then with a test light see if you are getting power to the fan motor. If not, check the switch and dropping resistor. If it is lack of warm air, you'll need to check the flow through the heater core. With the engine running, disconnect the return hose at the engine. CAUTION, may be hot water. If there is no water, perhaps you have a clogged hose or heater core.

Dec 06, 2009 | 1987 Chrysler LeBaron

1 Answer

Heater fan not working in a 1996 Chevy S-10

I looked at wiring diagrams at bbbindustries: the orange wire to the 20 amp htr fuse is direct from the ignition switch. You might check: that orange wire splices to the 10 amp brake fuse (fuse #12). check if that also has any voltage problems.
There are two black fusible links that supply power to the ignition switch. the fusible links come from the battery junction block.

May 26, 2017 | 1996 Chevrolet S-10 Pickup

1 Answer

Heater fan only works on high after replacement of heater core

It's very possible the fan motor has quit. The squealing noise is caused from motor bearing failure. As the bearings wear out or dry up the motor is harder to turn and require more current to run the motor. On lower speeds, the motor runs off a series of resistors that reduce the amount of voltage and current so the fan runs a lower speeds. If the bearings are worn, there is not enough voltage or current to turn the motor and that's probably the humming noise your hearing.
Good observation by the way.
Let me know.

Feb 13, 2009 | 2001 Chevrolet Prizm

1 Answer

Relay/resistor heater blower

There are two fuses for the fan. One is probably a 20 Amp in the fuse panel in the cab and marked "Heater". or "Heater/AC" The second is under the hood may be marked Heater, Blower, or Fan and should be 30 Amp. The one in the cab supplies switched 12 volts to the fan speed switch. The one under the hood supplies the 12 volts to the relay. The relay is normally energized by the 12 volts through the 20 Amp fuse in the cab and through the switch. I think you find that the fan has the normal speeds except for missing HI with the underhood fuse removed, and will turn off with the ignition that way. There is no hazard in operating it that way but you may want to replace the resistor/relay assembly before it gets too cold. The relay is a pretty trouble free device in most cases, maybe you can find a deal on a good one at a junkyard.

The whole idea with the relay under the hood started back in the Sixties believe it or not. There is considerable voltage drop in the wiring between the fan switch and the blower fan motor. By adding the relay under the hood right next to the motor, the voltage drop was reduced, both by the shorter wire, and by using heavier wire to boot. The motor gets really close to the full system voltage when the relay is closed. In your case where the relay keeps the fan running, it can drain a battery rather quickly too!

Dec 18, 2008 | 2004 Chevrolet Silverado 1500 Crew Cab

1 Answer

Parking lights and dash lights won't shut off

The park lights staying on indicates the switch is deteriorating.
I would replace it.
The door locks is probably a voltage issue. With the cold weather, the locks need more voltage to unlock. They get that voltage when the engine is running. If you really want the locks to work without the engine, you might try accessing the locks and cleaning them. Then use a lightweight grease, like lithium grease, to help them open with less power.

Aug 04, 2017 | 1998 Ford Expedition

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