03 MR2 SMT
Battery drain of 0.25 amps. After checking various circuits found that removing fuse ECU-B1 (25amp) solved the problem. Circuit appears to control radio and interior light. Removed festoon bulb but problem still there. Any thouhgts?
Not sure where the alarm gets its feed from the run and keep it's internal battery charged.
Do you have a standard head unit ... could be worth unplugging it to see what happens.
Radio needs constant live feed for memory does'nt it?Is your battery ok?
From experience as life of bryan says the radio needs a constant live feed to keep the radio presets, time and what not stored. I found that out after replacing the radio with an aftermarket one and not having the power constantly resulting in me having to retune the radio every time I started the car up.
Radios do take some power, but nowhere near 250mA.
Could be the alarm...? Some are quite power hungry.
Quote from: "Dan_R"From experience as life of bryan says the radio needs a constant live feed to keep the radio presets, time and what not stored. I found that out after replacing the radio with an aftermarket one and not having the power constantly resulting in me having to retune the radio every time I started the car up.
radios have to have a constant live power. they also take power from the ignition to turn them on when you turn the key
0.25A is very high. At this rate the battery would be too flat to start the car after less than 2 weeks. How did you measure the current, if you were using a clamp meter was it zeroed before you took the measurement?
Hi,
In my opinion, there is no way the standard radio or for that matter any radio, should be pulling that amount of juice. In my experience a normal battery being run in a car on a daily run basis should be able to cope with the small amount of drain overnight. IMHO it's either the battery not holding the charge or something else.
B
If it's an SMT, I thought the pump for the gearbox always checks for the door being opened and fires itself up. If it's always checking (I presume on that fuse line you mentioned) that'll be the drain. My cars an smt and drains after a couple of weeks also.
I don't have the diagrams, but I'd be surprised if the SMT didn't have it's own fuse. It's an interesting point about it checking the door, so the ECU is still powered even when the ignition is off. However, I'd hope it had a low power mode for this operation, using a lot less than 0.25A