93 Accord, Circuit problem

Rpg0 · #1 08-12-2008, 10:50 PM

Instrument light fuse blew. Replaced it and now the chime continues to go off when key is out and lights are off. A/c Blower stays running as well...

Any idea where to start ??? I gather a short somewhere.

Thanks,

jeffcoslacker · #2 08-13-2008, 08:33 AM

http://econtent.autozone.com:24991/z...528005fa2d.gif

Looking at the diagram, the only way the blower can run is if the blower control relay is hot, which is supposed to only happen in "run" position...

Additionally the blower switch supplies the ground for the blower motor, and in the off position should deny any ground to the blower...so it shouldn't be able to run with the blower switch in the off position even if the relay is still hot for some reason....

Can you turn the blower off with the switch, in other words does it just continue to run if the blower switch is in an active position, turns off if you turn it off?

Just trying to get a feel for exactly where the problem lies...

Which fuse # was it that you replaced when this all happened?

Rpg0 · #3 08-13-2008, 08:58 PM

The fuse in question is the small light fuse(labeled on top of the under hood fuse panel), a 15amp fuse. Fuses aren't numbered anywhere. When pulled, I have no fan ,no instrument lights, no tail lights. With it in, Tail lights lit(Light switch off), instrument lights lit and blower fan will run when turned on(Blower will turn off with the switch) all with key off and Chime contnues to chime like the lights are on(Tail and instrument lights are on) or the key was left in the ignition.

Got Dark on me. So I guess I'm gonna have to pull out the meter and start runing circuits this weekend.

jeffcoslacker · #4 08-14-2008, 08:04 AM

They have to be numbered in some way for reference, sometimes it's molded into the box and hard to see though.

What you said about the blower means that it's at least being powered by an energized relay, not getting feed from another source. I can"t find anyplace that the blower relay feed (fuse#8, 7.5a) relates to the headlight switch fuse, which feeds all the taillights, etc (fuse #23, 15a)

There is a feed off fuse #8 (blk/yel) that splits, one wire going to the blower relay, one to the radiator fan control module. It supplies voltage with key on to close that relay so the blower can run. The blower's actual power is fed through fuse #18, 30a, which is always hot. So as long as the relay control side has power, the blower will be powered, even with the key off.

So it seems to me the key to finding the problem is to isolate where the blower control relay is getting an alternate power source with the key off...that should be relatively easy to figure out.

The only other alternative is that the blower relay got stuck closed, which would explain it's behavior but not the other stuff.

Wherever the blower relay is getting fed from seems to be powering the instrument lights and taillights too, independent of the headlight switch...

Next question, do the lights stay on when you turn the blower off? I assume so, since you didn't mention it. But if they didn't that would narrow it down considerably...

Rpg0 · #5 08-15-2008, 06:04 PM

Not a molded number anywhere on that fuse panel. All it says is 15a, Small Light. I've had this thing about a year. I just noticed the fuse I pulled out was a 30a and should have been a 15a. I'm wondering if that has anything to do with my problem... like wires burned together... I'll have to thank the PO if it is.

I see the circuit in the diagram. I cant see anything either that would crossover to make happen whats happening. Unless I have 2 problems(coincidence?).

Lights do stay on when I shut off the vent blower.

Thanks,

jeffcoslacker · #6 08-15-2008, 07:02 PM

Can you locate the blower relay? I don't know where it is.

I'd unplug it and verify that this stops the blower. If it does have power feed to the control side w/key off, I'd follow that wire back to the problem.

Remember it does have a constant battery power feed on the supply side, that's normal. Should only be one live wire w/key off. Make sure the relay clicks when power is pulled from it, to rule out a stuck relay.

I really think a close look at that circuit will take you to the problem...

Rpg0 · #7 08-19-2008, 02:50 PM

Located the source of the blower running problem. Turns out an aftermarket HD-Radio wiring harness had melted into the power for the blower and was providing an alternate source of power to it from the always hot feeding the memory for the radio.

Still have Tail lights and dash lights on when light switch is off and key off. The chime I'm hearing is for the lights being left on. Going to go into the steering column and disconnect the switch to see if it's a bad switch.

Thanks,

jeffcoslacker · #8 08-19-2008, 09:23 PM

Quote:

Originally Posted by Rpg0

Located the source of the blower running problem. Turns out an aftermarket HD-Radio wiring harness had melted into the power for the blower and was providing an alternate source of power to it from the always hot feeding the memory for the radio.

Still have Tail lights and dash lights on when light switch is off and key off. The chime I'm hearing is for the lights being left on. Going to go into the steering column and disconnect the switch to see if it's a bad switch.

Thanks,

Good idea...I meant to suggest that and forgot...just for laughs unplug the ignition switch too and see what happens if the headlight switch doesn't do it. Then you'd know it was being fed through an ingnition fed circuit, at any rate...narrows it down slightly..

Good luck! Glad you're getting somewhere with it. Electrical glitches suck.

jeffcoslacker · #9 08-19-2008, 09:25 PM

Never mind...i'm a little dim this evening...that probably won't prove anything.

Pull fuses until the tailights go out, see what's on that circuit and go from there?

Rpg0 · #10 08-20-2008, 07:17 AM

The tail lights and instrument lights are on the same fuse which I have pulled to keep from running battery down. So it's just that one circuit. I'm guessing light switch. My front running lights dont come on even with the fuse in and switch on.

I guess I'll be riding my bike when this rain quits... Until then my sons car will have to do.

Rpg0 · #11 10-20-2008, 12:05 AM

Finally had a chance this weekend to take a look at this problem.

Disconnected the multi-light switch and lights stayed on with the light on reminder chime going off. Also disconnected Ignition switch with same results.

Removed fuse under hood, from diagrams I found online, it shows to be #27. With it out I lose rear taillights and dashlights. Wierd thing is, I have no front running lights at all...

Gonna have to take it a wire segment at a time I guess until I find it.

Rpg0 · #12 10-26-2008, 09:34 AM

Took some time this morning to chase wiring. Started at the switch, unplugged it, lights still on, went to the next connector up under the dash unplugged it... Lights off! Pulled the 1' wiring lighting harness that runs with the 1' ignition switch harness. Opened it up and found a major meltdown in the lighting harness. Correcting it now.

I believe the PO had problems with the running lights. Must have blown a fuse and they replaced it with the 30a fuse I found in it, which obviously didnt blow and melted everything.

Gotta luv it, NOT!

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