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View Full Version : ECU Power Drain Stumper!



dbrunges
04-07-2015, 11:31 AM
1987 Might Max (Actually Dodge Ram 50) with 2.0 manual transmission. Fully charged battery drains with 6 hours. Hot circuit though ECU (mounted on front right firewall). Looked at some of the old fix it books and it suggests power should be cut off to ECU when key is off. Replaced Ignition Switch and ECU. Still drains power. Removed ignitions switch, pulled all the wire connectors and still have power drain. Red-blue wire is hot. Any ideas on where this has crossed with another power wire? Fuze block? Where is the sneaker circuit? Old wiring diagrams leave a lot to be desired. Suggestions appreciated.

Bad ballast resistor or incorrect wiring at coil?

Help.

Thanks.

LSR Mike
04-08-2015, 10:43 AM
MPI Relay

dbrunges
04-08-2015, 03:29 PM
Thanks for the reply. Will give it a look.

Yoshiwarrior
09-23-2018, 06:34 PM
I'm having this problem. It seems to die faster when it's colder outside. So I started unplugging the battery when I know it's gonna sit for more than a couple hours. I'm getting pretty fed up with having to jump start it. At first I thought it wasy the radio. I have a stereo system in my truck. So I unplugged the radio, also unplugged my aftermarket lights, and it's still gets a dead battery. I put a starion alternator on the truck recently and used wire butt connectors, temporarily, for the field terminals, till I get the correct pigtail for it. I know there's not much to the electrical sustems on these trucks. So maybe that's why it's got me stumped. Is there a common problem I can check. Wiring is my weakness, so ideas would really be appreciated. If someone has a diagram for the fuses or something too. Thank you!

lush90
09-23-2018, 08:42 PM
I'm having this problem. It seems to die faster when it's colder outside. So I started unplugging the battery when I know it's gonna sit for more than a couple hours. I'm getting pretty fed up with having to jump start it. At first I thought it wasy the radio. I have a stereo system in my truck. So I unplugged the radio, also unplugged my aftermarket lights, and it's still gets a dead battery. I put a starion alternator on the truck recently and used wire butt connectors, temporarily, for the field terminals, till I get the correct pigtail for it. I know there's not much to the electrical sustems on these trucks. So maybe that's why it's got me stumped. Is there a common problem I can check. Wiring is my weakness, so ideas would really be appreciated. If someone has a diagram for the fuses or something too. Thank you!

Check out scannerdanner YouTube video on parasitic draw, great explanation. Also, bbbind.com has all wiring diagrams.