Battery drain-current test - Ignition switch in OFF position
The ULTIMA RED-TOP battery was selected for the KJ CRD because the AGM construction could hold maximum charge for long periods of non-use, as resulted due to low sales rate as compared to the spark-infested V6 models, and for probability of week-end, month-end, or vacation-only RV usage - the RED-TOP reduced charging maintenance intervals vs standard lead-acid batteries, necessitated due to the increased starting current required by the 2.8L CRD engine
Several control modules, incl ECM, TCM, BCM, FCM, ABM, are fused for direct-connect to battery, as is the alternator\regulator - these all draw very minimal current from the battery, usually in microamps, with all combined current drains normally in the low milliamp range
If increased current drain is suspected as causing over-nite low battery voltage this test will reveal normal to excessive parasitic drain - Remove NEG battery cable - set DVM to CURRENT\AMPS, initially in 10amp range for manual DVM - AUTO-RANGING DVM will automatically select appropriate amp range - current flow is negative to positive thru the IGN circuit, so: - connect DVM RED\POS\+ lead to NEG batt cable - connect DVM BLACK\COMMON\- lead to NEG batt post - read KEY-OFF current drain, reducing DVM AMP range as necessary to increase resolution - total current drain from all modules should be in milliamps, incl Remote Key Entry and alarm system
Added for clarity to determine pass\fail results: - decreasing drain to minimum static level would be normal - increasing drain to maximum level would be a fault - most DVM's have a sampling\refresh rate of ~300ms or so (inexpensive versions even greater), so any decreasing or increasing change in drain current may not be indicated or observable
Coming soon to a forum near you: For your continued entertainment, actual open-hood in-situ parasitic drain tests, in series-insertion and clamp-on scenarios, replete with real-world measured values from microamps to milliamps, and all points in between Don't miss it - be there, or be square
_________________ '05 CRD Limited Pricol EGT, Boost GDE Hot '11; EDGE Trail switched SEGR; Provent; Magnaflow; Suncoast T\C, Transgo Tow'n'Go switch; Cummins LP module, Fleetguard filter, Filterminder 2.5" Daystar f, OME r; Ranchos; K80767's, Al's lifted uppers Rubicons, 2.55 Goodyears Four in a row really makes it go
Last edited by gmctd on Fri Jan 30, 2015 8:35 pm, edited 4 times in total.
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