Electrical Problem

[mik9185]

Got a 2000 Civic EX the battery light comes on then after it revs over 4k it turns off untill the engine is under 4kRPM then it turns back on. Driving the car home the other night the tach and speedo stoped working and the SRS light turned on. WTF is wrong its driving me crazy right now?

[LS/Vtec]

alternator. possibly a loose connection if it only does it under 4k.

[mik9185]

then why would the speedo and tach stop working?

[LS/Vtec]

your lights prolly cut in n out too? If they were on? Most likely you are running on just your battery and your voltage is getting getting low so your electronics will start to cut in/out cuz thy dnt have enough power.

Try this

Put a voltmeter on the battery while the engine is running and turn on all the lights, air conditioner and rear window defroster and the voltage drops to less than 12 volts, the alternator is bad.

[mik9185]

ok good look man.

[bryantb18c1]

thats gotta b the alternator, make sure u have the right fuse for the alternator and speed sensor, which is the same fuse, if nething put a bigger fuse, or somethings gotta b lose but first id check the alternator

[CTB16_LSD]

ive got the same car and this just happened to me about 2 weeks ago its most def the alternator ...to confirm start it take the pos off battery if it shuts off then alternator is your problem

[LS/Vtec]

thats gotta b the alternator, make sure u have the right fuse for the alternator and speed sensor, which is the same fuse, if nething put a bigger fuse, or somethings gotta b lose but first id check the alternator

DO NOT put a bigger fuse to fix the problem if the fuse is popped! Unless you wanna take the chance of it setting your car on fire.

[bryantb18c1]

lol hahahahahah wel yea im sayin if the fuse he has is like 8.5 then put 10, ur cars not gonna set on fire if you put the right fuse, im jus sayin he cud have the wrong fuse in there

[astroboy]

Alternator. End thread.

[redeg666]

bring it to the part store (the car or just the alternator) they can chech it

[H22SteakSauce]

I'm willing to bet the alternator is fine and his harness messed up. I had the same problem wit my ek and it's cuz the harness rubs on the bracket from the Intake manifold to the block and takes the insulation off. Then the circuits grounds when ever it wants and the car goes crazy. If any fuses are popped it's gonna b fuse 15 I think. And it's a 7.5. Amp. Easy fix tho.

[mik9185]

Fuse 15 isnt popped. i already fixed the harness grounding out on the underside of the intake manifold. i was told it could be an issue with the O2 sensors.