Suggestions about Car not starting in wet weather?
Asked by Rdmupton Feb 24, 2020 at 09:22 AM about the 2009 Subaru Outback 2.5i Limited
Question type: Maintenance & Repair
The battery is less than a year old, altenator provides 16 amps while running
so I've ruled that out. The lights and other electrical devices work properly
before, during, and after trying to start. Occasionally, a small black box near
the top / center of the engine makes about 3 or 4 ticks then stops. The car
never tries to turn over but when it does, it starts immediately w/o any effort.
I've checked the wires / connections and they seem OK. Only seems to
happens during wet weather but the engine compartment is dry... Seems
electrical in nature but I'm stumped.. Help please!
7 Answers
16 amps from the alternator is nothing. Do you mean volts?
TheSubaruGuruBoston answered 4 years ago
And that would be overly high voltage! I'm guessing your top-mounted coil-pack has corroded terminals (clean 'em!), or an internal short that's draining ignition voltage to ground. Both conditions are common in 2000-2012 OBs. The coil-packs are cheap online. Not a bad idea to install nice iridium plugs and wireset at the same time. Delaer will charge you $550 for this. DIY for under $200 total. Good luck. Ern TSG/B
TheSubaruGuruBoston answered 4 years ago
Forgot: what's happening is that wet air conducts high voltage very easily, especially if there's a high resistance from corroded coil-pack terminals. As well, a cracked coil will short to ground in moist air. Clean everything up! Note that a CEL PO30x will indicate which wire is shorting, but check 'em all. If you have multiple PO30x codes then your coil-pack is shorting out.
TheSubaruGuruBoston answered 4 years ago
16v? Hmmm...regardless, proceed as above. It's rare to have the alt's internal voltage regulator fail in a way that BOOSTS voltage. Usually they just become intermittent and prevent battery charging, resulting in a 12v reading when idling. But deal with that after the coil-pack/wires/plugs scenario as I suggested. Ern TSG/B
Thanks.. I'll take your advice SCG/B and look for coils/ wires and replace... I had a mechanic tell me that the ground to the starter was corroded and that would fix the problem. It is a copper braided ground that does look in bad shape but I'm not confident that will solve the problem. What you suggested makes much more sense and not a big expense. Thanks again...
