Short Circuits troubleshooting

"no power"... You mean "power" when the load is connected.

If I have power

If the loads on the circuit branch are disconnected (turned off) and your test lamp is lit there is a short curcuit. Some circuits can have continuos loads on them, but would be small and not enough to make the lamp glow. The resistance of the short or load has to be low or the conductivity high in proportion to the test lamp for the lamp to glow. If the lamp and shorts resistance values are 50/50 the lamp will glow at about half it's brightness. If the short is direct (0 ohms), the lamp will glow at full brightness.

I understand power is coming from the

The battery is always grounded. The fuse is connected through a buss in the fuse box to the battery positive terminal through a main fuse.

in article 5b5wb.8918$ snipped-for-privacy@nwrddc02.gnilink.net, Cracker Jacks at snipped-for-privacy@verizon.net wrote on 11/23/03 8:24 AM:

Sounds good. Try using a lamp, like a tail lamp where the fuse would be connected.

Bill

The other responders posts are very good suggestions about using a lamp bulb where the fuse goes to help find the short.

I have a question. Which fuse is blowing? If it is your dash lights that are out, I suspect that you just lately installed a radio, tape, or CD player.

ARM

If it doesn't make itself obvious, get a Xerox of your car's electrical diagram out of National Service Data (best diagrams IMO) at your library.

Some stuff is not logical. Mine has dome lights on the same circuit as radio memory / clock. (You'd never know it looking at the fuse block.)

No actually it is a 20a fuse under the hood in the engine compartment. The fuse is for Horn, Stop and seat belt retract. It's part of the brake warning system. Leads to a brake safety warning sensor (light bulb out ect). The brake lights will not work with the fuse removed. The fuse does not blow with the left sensor removed, but with the left senor removed, I have no left brake light.

There is a shop manual on line at

The two sensors are connected in series. Shop manual indicates that there is a diode in one of the sensors (oftentimes the Honda manuals simplify things by not showing irrelevant components, there may well be a diode in both, even though it is not shown). The most common failure mode for diodes is that they short circuit. If this were to happen in the one sensor you could get the scenario where you can plug in a bad sensor and the fuse still would not blow, leading to a false conclusion that the sensor is good. Assuming the schematic at is correct for your car, you would get:

Bad sensor in left socket, good sensor in right socket: Fuse would blow

• Bad sensor in left socket, right socket empty: Fuse would not blow Left socket empty, good sensor in right socket: Fuse would not blow

Good sensor in left socket, bad sensor in right socket: Fuse would blow Good sensor in left socket, right socket empty: Fuse would not blow Left socket empty, bad sensor in right socket: Fuse would blow

Page 25-68 of the manual referenced above shows how to test the sensors. If you get c>

Our library here is small do you think they would have it? Do you think there is a Library online that may have it?

My reference is a bit dated:

http://216.239.57.104/search?q=cache:HRwSNbfOCzMJ: Service Data is now called Mitchell's Chilton's, Mitchell's, and Motor's are the Big 3 in independent repair manuals. Any library that can truly call itself that should have all 3. In the big city there are multiple copies of each.

I'm thinking no.