Engine dies when fan or defog or lights etc are turned on...what is up???

Tankota · May 12, 2007

This is my econobox commuter. ('85 honda) Just started this week. Car runs and idles fine until you turn any of the following by themselves: the fan, the headlights, the rear defrost, the aftermarket running lights. Then the idle drops REALLY low and gets a bit erratic (all below idle speed) until the engine dies.

What I've checked/replaced so far:
I replaced the negative battery cable and it still does it.
Battery tests fine at autozone and starts the car just fine (12ish volts while off and 14ish volts while running).
The alternator failed 2 of 4 tests at napa so I got a new one and the dang car still does it (nice way to spend $100:booo: )

Any ideas on what would fix this?

Not Jobless · May 12, 2007

Tankota said:
This is my econobox commuter. ('85 honda) Just started this week. Car runs and idles fine until you turn any of the following by themselves: the fan, the headlights, the rear defrost, the aftermarket running lights. Then the idle drops REALLY low and gets a bit erratic (all below idle speed) until the engine dies.

What I've checked/replaced so far:
I replaced the negative battery cable and it still does it.
Battery tests fine at autozone and starts the car just fine (12ish volts while off and 14ish volts while running).
The alternator failed 2 of 4 tests at napa so I got a new one and the dang car still does it (nice way to spend $100:booo: )

Any ideas on what would fix this?

It's shorting out when you turn **** on and dropping all the power from the battery that the motor needs for plugs, coil, etc...

Maybe a bad fuse box?

blackcj71 · May 12, 2007

Check your IAC (idle air control) module if that aint working that will cause what your experiancing..

archer1965 · May 12, 2007

make sure your voltage regulator is working properly. :awesomework:

Tankota · May 12, 2007

I went and looked at the fuse box...couldn't find anything burned or melted in/around it.

Thanks for the tips. I'll check em out tomorrow.:beer:

crash2 · May 12, 2007

I agree---the extra load is pulling the motor down and if the IAC is bad it will cause the car to stall....

Tankota · May 12, 2007

Possibly ignorant Q: Do carbureted vehicles have an IAC?
This car is not fuel injected.

crash2 · May 12, 2007

Tankota said:
Possibly ignorant Q: Do carbureted vehicles have an IAC?
This car is not fuel injected.

Some have an idle up soloniod

Tankota · May 13, 2007

Didn't get a single chance today to mess with it. However, yes I remember a quadrajet...wait, my quadrajet has a idle up solenoid that I wired to come on with my air compressor. Now I know what I'm looking for:beer:

Fullywrecked · May 14, 2007

Check the kanooter valve and get replace the flux capacitor. It will run like a :squirrel: once agian.

junkyard jim · May 14, 2007

They have an idle circuit on the carb that gets clogged. (It's supposed to shut off fuel when the car is shut off to avoid dieseling) Try crossing #1 and #4 wires with the air cleaner lid off and making it pop (backfire) a couple times to clear it out.