Skip the auto shop - Our mechanics make house calls

Q: Electrical power drops out completely while driving.

asked by on

2003 Jeep Grand Cherokee Laredo 4.0L 305,000+ miles. On startup in the morning, when I put the car in drive and stepped on the gas, electrical power would sometimes drop out completely, then comes back, then does it again sometimes 5 or 6 times (i.e., RPM's go to zero, gas gauge goes to empty, speedometer goes to zero, engine stops running, etc.). Wiggling the key always resolved the problem but sometimes it took several tries (and sometimes a couple of restarts) to find a "sweet spot". After it resolved it ran fine, but once in a great while it skipped a beat again. Throughout the day when I started it the same thing would happen, but not as bad. I have replaced the ignition switch with a new one from Standard Electrical Product. It greatly improved the situation, but sometimes it still happens. Question is, short of having gotten a defective ignition switch off-the-shelf, is there anything else that might cause this? (Bad relay somewhere, etc.) Thanks.

My car has 305000 miles.
My car has an automatic transmission.

A faulted automatic shutdown relay or asd relay is a common concern on your vehicle model and can show the same symptoms. I have seen this problem caused by the relay as well as corrosion inside the under hood fuse block so that would be a good place to start looking around. Consider hiring an experienced technician like one from YourMechanic who can come out and take a closer look at your loss of power or stalling concerns and offer a more personal diagnosis.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: My jeep won't even crank

This may potentially be related to a faulty starter relay. The starter relay directs power from the battery to the starter solenoid which then engages the starter when you turn the key. When this is not working properly, you may...

Q: My car is overheating even after replacing waterpump and thermostat

Hi. It sounds like the heater core is clogged and restricting the flow of coolant in the coolant system. There is also the possibility that the new radiator is defective and is causing the car to overheat. The head gasket...

Q: Truck shuts off, hard to restart - 2000 Dodge Ram 2500

Hello. The neutral safety switch should be checked for proper operation. There could also be a problem with the glow plugs and turbo system. Another possibility is that the fuel injectors may be causing the problem you are experiencing. Have...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...