After teaching a seminar recently, I received an email from an attendee, who works in a shop in Mississippi, asking me about one of the topics I discussed in the class. Essentially, I had reminded attendees that the automakers recommend (and I-CAR teaches) that before technicians do any welding on vehicles, they should first disconnect the battery of the vehicle and remove (or pull back) any wiring harness or electronic components that are within 12 inches of the weld area.
The gentleman from Mississippi asked about some of the electrical issues if the technician is using a “memory saver,” which is a low-cost device that typically use a 9-volt battery plugged into the car’s auxiliary power outlet (or cigarette lighter) to keep power directed toward the car’s radio or other components to maintain their memory settings. The Mississippi technician wondered if a memory saver was a good alternative to disconnecting the battery and losing some electronic memory information.
I was pretty sure I knew the answer to that question, but decided to put it out to some of the technical experts I know and respect in this industry. Their unanimous conclusion: They don’t recommend the use of memory savers.
“We do not use memory savers,” said Will Latuff, manager of the fourth-generation Latuff Brothers collision repair business in St. Paul, Minn. “They are not effective or worth the risk. I-CAR also teaches not to use them.”
Jeff Peevy, I-CAR’s director of field operations, concurred. “A memory saver can complete circuits that removing the battery opens in order to protect the system, and so a memory saver could put systems at risk,” Peevy said.
George Hogan, a business development manager with Axalta Coating Systems, agreed that welding has the potential to expose vehicle electronics to overly high voltages and amperages.
“There is also likely increased risk of fault codes being stored if the circuitry is exposed to unexpected signals if the modules are ‘awake,’ powered up from either a connected battery or a memory saver installed,” Hogan said.
Hogan said he recently spoke with an automaker engineer who noted that some vehicle electronic systems stay powered-up, even with the key off.
“Think of keyless entry systems, as they are always looking for a signal from the electronic key,” Hogan said. This could put these systems at additional risk if welding is done on the vehicle without appropriate steps being taken first.