I get to the parts store last night to pickup some brakes for my other car, I was driving my 97 civic h/b, and notice the speedo stoped working...then ALL (headlight, all interior, tails) the lights are dimming, back on, dimming, then back on...just doing that constantly...also the speedo is acting real weird too, it's not reading the speed, it's just jumping all over the place...going down to 220, then back down...it seems to be just jumping around randomly...this is happening under load, at idle, everywhere..my audio is completally off

I got no idea where to even start looking...seems like a bad ground...but not sure how to troubleshoot this


this started happening as I pulled into the parts store...was fine all the way there, and did it all the way back

the car still drives but it does this...messed up

 

there is a brown wire on the back of the intake manifold that may be rubbed raw. Look for it where the loom is making contact. You also have the year that came with the batch of defective alternators on a portion of them. A failing voltage regulator inside can cause some of these symptoms...not the bouncing speedo though.

A bad ground at the battery can always cause havoc across an entire electrical system.Happy hunting

 

Is th cel on? Any trouble codes stored?

 

my CEL light is burnt out

tell ya teh truth I never even thought that this could be throwing a code, I will put in a new bulb when I get home and check it out


oh ya and Moto...I have a Y8 IM swap...and I didnt extend none of the wires there...and they are real tight, I will check that out too

 

How your batt., alt.?

 

they been fine

but here's the thing, if it was alt/batt, why would they be dimming and back on randomly, both under load and idling?

I would think it would have diff symptons, correct me if I'm wrong

 

checked the CEL's after resetting it again

code 41 and 65

45 Fuel system too rich or lean
65 Secondary oxygen sensor heater

45 wouldn't cause it

65 could, so I disconnected my 2nd o2, which should bypass all electrical from going there and the problem remains

I made sure to reset the ECU in between

 

another thing, doesn't seem to do it right away, sometimes

when I first reset the ECU, it didn't do it until I started moving

then after I was pulling into my lane, when I put it in R...ti stoped for a few seconds, then staretd back up

seems real intermittent

I gotta find me a spare distributor to test this

 

note to self...check engine ground tommorow

 

On both of the things I mentioned they are factory technical service bullitens and issues in stock form. As to the loom, it was doing it from factory set ups so yours may be more prone. As to the voltage regulator, I went through this with my personal vehicle and have seen it on many customers cars. The voltage regulator in the alt starts going and it clips the amount that the alt can charge so the voltage swings back and forth rapidly up to 4 volts depending on the condition of your battery, stereo mods, etc. It may get worse, it may go away for a few months and return.

if you have a volt meter check it out and it will be easy to catch. usually suspect cars will only be charging at 12. something at idle. If so, dead ringer. It could be other things like ground issues but on that particular car these are two things to definately rule out before chasing your tail on a ground fault that could be many places.

 

k sweet

I will follow your list of suggestions tommorow evening and see if I can find it

 

ground is fine,
also checked for wires behind IM...all appear fine

I tested the alt+batt both seem fine
charges at about 13.7ish with some throttle
idle like 12ish I believe

here's another thing I realized
if I start the car and just let it idle...it's ok
as soon as I touch the gas, is when the jumping of lights begin

I am gonna take the alternator from another car to test it, any other ideas meanwhile?

it almost feels like the car is chugging, but it's doing this jumping even under load

this is so confusing, I hate cars

 

what signal would be sent when the gas is pressed? and then keeps on being sent

something that is like activated

?

 

My 98 Civic EX did the same thing where when you hit the gas the lights inside and out would dim. Even when I hit the brakes... I didn't pay much attention to it though because I was trading it in for my Prelude. And a light was out above my temperature sensor... it was weird...

Good luck though...

 

thanks

bump

 

my 97 ex was just doing the same thing.....check the #15 fuse under the dash on the driver's side.....i replaced it and all my problems were gone.....no more lights dimming speedo works again and everything is cool.....good luck man

 

try a donar battery, just do it