NEW YORK (AP) -- Wells Fargo plans to test a $3 monthly fee for its debit cards starting this fall.The San Francisco-based bank said the fee will be applied to checking accounts opened in five states starting in October. The fee would be in addition to monthly service fees ranging from $5 to $30 that Wells Fargo already charges.Although it's unusual, Wells Fargo isn't the first major bank to test whether customers will be willing to pay to use their debit cards. Chase last year also began testing a $3 monthly debit card fee in northern Wisconsin.Other major banks have also revamped their lineup of checking accounts in the past year or so, in many cases by hiking monthly fees or adding conditions customers must meet to qualify for fee waivers.At Wells Fargo, for example, monthly service fees can be waived if customers set up direct deposit or maintain a certain minimum balances.The industry's experimentation with fees is partly a response to a new regulation that will sharply reduce the revenue that banks collect on checking accounts. Starting this fall, a new cap will limit how much banks can collect from merchants whenever a customer swipes a debit card. It's not clear exactly how much banks will lose. In 2009 banks collected an estimated $19.7 billion in such fees from merchants, according to the Nilson Report, which tracks the payments industry.Wells Fargo has said it plans to recover about half the revenue it loses from the new regulation, either through product changes or volume growth. Earlier this year Wells Fargo announced that it was ending its debit rewards program. Chase has also ended its debit rewards program and PNC Bank will no longer give customers with free checking accounts rewards for debit card purchases.For now, Wells Fargo's $3 debit card fee test will be limited to accounts opened in Georgia, Nevada, New Mexico, Oregon and Washington. A spokeswoman for the bank, Lisa Westermann, did not say when the bank would decide whether to roll out the fee in other areas.The test comes at a time when consumers are increasingly relying on debit cards.An Associated Press-GfK poll last month found that about two-thirds of consumers use debit cards more frequently than credit cards. When asked how they would react if they were charged a $3 monthly fee for their debit card, 61 percent said they'd find another way to pay.If the fee was $5 a month, two-thirds said they'd do the same. If the fee was $7, the figure rose to 81 percent.