br1anstorm
NAXJA Forum User
- Location
- United Kingdom
I have a 1993 XJ Sport, 4.0 engine, auto transmission, standard spec (no major electrical mods or accessories). I need help in tracing a battery drain problem.
I replaced my previous battery a month ago. It was 7 years old, wasn't holding charge, struggled to turn the starter, and the little indicator showed "charge/replace". I assumed it was worn out, and replaced it with an Optima Red Top (expensive and hard to find in UK!).
This weekend, after sitting for only 3 days, the jeep wouldn't start. Battery flat - dome light barely glowing. I checked all the obvious things: I hadn't left the lights on, the interior courtesy, glovebox, and underhood lights all went off properly, and the battery connections all seemed clean and tight.
So I charged the battery overnight, and did some more research (I'm not an engineer or auto electrician). I have now just done the "parasitic drain test". Disconnected negative cable, and put my analogue meter between neg battery post and cable, with ignition and all lights etc off (including underhood light, which I removed). Here's the results:
Can anyone suggest a step-by-step sequence of further checks that would enable me to locate, or narrow down, the problem? I hesitate to go to a dealer, as apart from the cost, local workshops rarely see US-spec vehicles like mine; if I need something done, it helps if I can at least tell them what and where the problem is!
Expert advice would be appreciated...
br1anstorm
I replaced my previous battery a month ago. It was 7 years old, wasn't holding charge, struggled to turn the starter, and the little indicator showed "charge/replace". I assumed it was worn out, and replaced it with an Optima Red Top (expensive and hard to find in UK!).
This weekend, after sitting for only 3 days, the jeep wouldn't start. Battery flat - dome light barely glowing. I checked all the obvious things: I hadn't left the lights on, the interior courtesy, glovebox, and underhood lights all went off properly, and the battery connections all seemed clean and tight.
So I charged the battery overnight, and did some more research (I'm not an engineer or auto electrician). I have now just done the "parasitic drain test". Disconnected negative cable, and put my analogue meter between neg battery post and cable, with ignition and all lights etc off (including underhood light, which I removed). Here's the results:
- When connected, meter reads 48 (or is it 4.8) mA
- I pulled each of the fuses in turn on the interior fuseblock in driver's footwell. No change in meter readings except when I pulled fuse no 9. Meter dropped very slightly (to 42 mA). I figured this was normal - fuse 9 controls the radio/memory as well as interior courtesy lights etc, so I reckoned there would be a very tiny current draw there anyway
- So then I pulled each of the fuses in the relay/fuse block - aka the Power Distribution Centre - under the hood. No change in readings until I pulled fuse 2, the 30A one which is labelled 'Engine Cntrl', and on the wiring diagram connects to, and protects, the Powertrain Control Module (PCM). The meter reading dropped significantly - to 10mA.
Can anyone suggest a step-by-step sequence of further checks that would enable me to locate, or narrow down, the problem? I hesitate to go to a dealer, as apart from the cost, local workshops rarely see US-spec vehicles like mine; if I need something done, it helps if I can at least tell them what and where the problem is!
Expert advice would be appreciated...
br1anstorm