Topic: Dead '74 CB550

[Blacknine]

Help! My CB has been running great all day, put it in the garage and went to start it just now and all the electrics are dead. All 3 fuses are good, ignition switch appears to be in good shape and battery is fully charged. If i put a flathead on the main relay (starter solenoid) the bike will turn over but nothing lights up. I also tried jumping the switch but nothing happened. Any idea where I should go from here?

[ekpent]

Ignition switch Hmmmmmm--Wiggle the key and start there tracing wires maybe.How old is the battery and is your charging system good?

[MoMo]

Check the battery cables to make sure the terminals are clean, also, the negative ground at the frame. Make sure the connection plug is tight at the ignition switch...Larry

[ekpent]

I updated but +1 on Larry----------

[Spanner 1]

Shorting-out the solenoid sends power to the starter only... so normal.
How sure are you that the 15A main fuse and it's fuse holder are good..... ?

[Blacknine]

Unless the fuse holder is bad, I took out each fuse, checked them, and then jumped it with a piece of wire instead of the fuse and still nothing. I don't even know where else to look on the bike at this point

[GoatBaSS]

Check the fuse housing. I have seen many needing to be replaced over the years. Look for melting...

[Blacknine]

Fuse housing looks ok. No melting or anything, one of the wires in the connector had been pushed out slightly, so I jumped it to the wire on the side of the connector and still nothing.

[bryanj]

You are going to have to be methodical with either a test light or multimeter and start at the battery checking for voltage then work along the system junction by junction, going here, there and everywhere is a road to frustration and insanity

[DavePhipps]

You are going to have to be methodical with either a test light or multimeter and start at the battery checking for voltage then work along the system junction by junction, going here, there and everywhere is a road to frustration and insanity

I  was about to reply when I saw bryanj's reply, so +1 on what he said.

[Gaither]

FWIW

Just looking  at fuses can fool you. When I was getting 3 miles to a 15 amp main, the bad fuses all looked OK. They were burned in the metal ends and didn't appear to be bad. This was caused by corroded fuse clips. An overload (short) will burn 'em in the middle were you can see the damage.

I twisted the end caps off and they were melted in the metal caps. Also, you can check 'em with an ohm meter.

Just a thought -

[Spanner 1]

Go Gaither....  ... Gaither +1.