BMW 740i Ballast Resistor Replacement at your home or office.

Our mobile mechanics offer services 7 days a week. Upfront and transparent pricing.

Estimate price near me

Service Location

Customer Ratings

(46)

Included for free with this service

Online Booking

Mechanic comes to you

12-month / 12k-mile warranty

Free 50 point safety inspection

Our certified mobile mechanics can come to your home or office 7 days a week between 7 AM and 9 PM.

Customer Ratings

(46)

Ballast Resistor Replacement Service

How much does a Ballast Resistor Replacement cost?

On average, the cost for a BMW 740i Ballast Resistor Replacement is $430 with $335 for parts and $95 for labor. Prices may vary depending on your location.

CarServiceEstimateShop/Dealer Price
1995 BMW 740iV8-4.0LService typeBallast Resistor ReplacementEstimate$784.53Shop/Dealer Price$969.42 - $1484.70
1993 BMW 740iV8-4.0LService typeBallast Resistor ReplacementEstimate$764.53Shop/Dealer Price$949.45 - $1464.75
1994 BMW 740iV8-4.0LService typeBallast Resistor ReplacementEstimate$764.53Shop/Dealer Price$949.45 - $1464.75
Show example BMW 740i Ballast Resistor Replacement prices

What is the Ballast Resistor all about?

Modern ignition systems use electronic circuitry to control voltage during engine starting and operation, but it wasn’t always this way. Older vehicles with points and coils did not have the benefit of circuit boards and computers, so another way to control voltage was needed. The ballast resistor coil was the solution. Think of it as a giant fuse in a way, although it serves a much greater purpose.

The ballast resistor coil plays several roles in your engine and charging system. In terms of position, it’s located between the ignition switch and the positive battery cable. During engine operation, the ballast resistor is responsible for lowering voltage applied to the coil to ensure that it doesn’t overheat and burn out, or damage the battery. During cranking, the ballast resistor allows normal battery voltage into the coil to ensure a good, strong spark for starting the engine.

The ballast resistor is subjected to significant amounts of heat during operation (the resistor’s resistance level increases or decreases with the application of heat and voltage). Over time, it will eventually wear out and need to be replaced.

Keep in mind:

  • The ballast resistor is not inspected during normal maintenance.
  • The ballast resistor is subject to significant amounts of wear and tear.
  • Ballast resistors are not generally found on fuel-injected engines.

How it's done:

  • The Ballast Resistor is verified that it needs to be replaced. The battery and battery tray are removed.
  • The defective Ballast Resistor disconnected and removed.
  • The new Ballast Resistor is installed, secured, and connected.
  • The battery tray and battery are reinstalled. The Ballast Resistor is tested for operation.
  • The vehicle is tested to ensure proper operation of the Ballast Resistor and road tested to ensure fan operation.

Our recommendation:

Over time and through normal use, the ballast resistor is subject to a great deal of wear and tear, and heat. This can cause it to fail unexpectedly. When this happens, your vehicle will experience unwanted, and perhaps dangerous, operation. It may crank but then stop running immediately after. Have any starting problems immediately diagnosed by one of our expert mechanics.

What common symptoms indicate you may need to replace the Ballast Resistor?

  • Engine cranks, but dies immediately when the key is moved back to the run position from the start position

How important is this service?

Without a ballast resistor, your engine will not operate unless you jump the resistor, which is dangerous, as it will eventually burn out the points, and is not recommended. If your engine dies immediately after turning the key back to run from start, likely the ballast resistor needs to be replaced. If the engine runs with the key in the run position, you may have another issue. Have it properly diagnosed by one of our expert mechanics immediately.

Fast and easy service at your home or office

Backed by 12-month, 12.000-mile guarantee


Meet some of our expert BMW mechanics

Real customer reviews from BMW owners like you.

Excellent Rating

(46)

Rating Summary
44
0
1
1
0
44
0
1
1
0

Peter

36 years of experience
346 reviews
Peter
36 years of experience
BMW 740i V8-4.4L - Window Motor / Regulator Assembly Replacement (Passenger Side Front) - Chula Vista, California
He was great. It was raining really hard. He still was very pleasant and did a good job on the repair.

Travis

18 years of experience
117 reviews
Travis
18 years of experience
BMW 740i L6-3.0L Turbo - Brake Rotor/Disc Replacement (Front) - North Charleston, South Carolina
Did a great job references for this service has been forwarded. Thanks

Lucas

21 years of experience
891 reviews
Lucas
21 years of experience
BMW 740i V8-4.4L - Battery will not hold a charge - Los Angeles, California
Very pleased with the service. Will recommend to my friends and family.

Eduardo

19 years of experience
554 reviews
Eduardo
19 years of experience
BMW 740i L6-3.0L Turbo - Oil Change - Houston, Texas
Timely, friendly and great job!

Excellent Rating

(46)

Rating Summary
44
0
1
1
0
44
0
1
1
0
Number of BMW 740i services completed
506+
services done by our mechanics
TOTAL NUMBER OF EXPERT BMW MECHANICS
1100+
experts on our platform

Recent articles & questions

How to Get an Iowa Driver's Permit
Like Like most states, Iowa requires all underage drivers to participate in a Graduated Driver Licensing program. This program states that those under 18 must obtain a learner’s permit that graduates to a full license as the driver gains experience...
How to Fix a Flat Tire
Knowing how to fix a flat tire on a car is part of being a safe driver. Driving on flat tires is dangerous so it's smart to repair flat tires quickly.
P0690 OBD-II Trouble Code: ECM/PCM Power Relay Sense Circuit High
P0690 means a high voltage problem with the power supply to the ECM/PCM which may cause Check Engine Light to come on or the vehicle will not start.

What would my next step be? Wheel bearings are driving me crazy!!

This is a common sound when wheel bearings are badly worn and need to be replaced (https://www.yourmechanic.com/services/wheel-bearings-replacement). When they wear out, the bearings begin to grind metal on metal which as you know creates an intense heat. This can be...

Trouble starting car when cold

The starting (https://www.yourmechanic.com/services/car-is-not-starting-inspection) issues scream timing. The typical causes that set these codes are the cam (https://www.yourmechanic.com/services/camshaft-position-sensor-replacement) and crank position sensors (https://www.yourmechanic.com/services/crankshaft-position-sensor-replacement). The only option you have not tried to my knowledge is the camshaft position sensor. I would start...

Heater does not blow hot air.

Hi there. Check the coolant level in the radiator and make sure that its full. Check the heater core valve near the firewall in the engine compartment and see if valve is working. Feel the heater hoses before the valve...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1 (855) 347-2779 · hi@yourmechanic.com