1973 Datsun 620.... NO Electrical now... Help !

[Superfunk]

Hi all;

 

My 1973 Datsun 620 had the following modifications done by the former owner.  ( other than these it is stock. )

 

1. L20B motor.

 

2. Electric fuel pump.

 

This is the way the truck was when I bought it, and I made No Modifications other than ALL new brakes.

 

Yesterday I tried to start my pickup, and I heard the elect fuel pump working, and then it stopped. I tapped lightly on it, and the fuel pump started again, but it still wasn't getting any gas to the carb..

I then turned the truck off, and went inside for a while.

Later I then went back to try again, and when I turned on the ignition to start the truck, the Red CRG. and the BRK. light on the speedometer immediately flashed on, and off, and then a loud Boom like a Fire Cracker, and then ALL of the electrical went dead, nothing, no lights, no radio, not even a click on the started solinoid, everything is now dead. 

I can't figure out where to start, or how to fix it.

When I looked at the wiring I saw that someone had cut the wire where it looks like a Fuseable Link was cut out, and the wire twisted together on the positive side of the battery. Does anyone have any idea what I need to do to fix the electrical again.?  ( The battery is new, and works fine in another car. ) 

 

Thanks George

[ggzilla]

1. Disconnect battery cable

2. Get a new Fusible Link and put it in

3. Turn everything off

4. Touch battery cable to battery

 

* if there is no spark, connect it up and drive off

* if there is a spark, start troubleshooting

 

They may have wired the fuel pump without a fuse. That's a no-no because if there's a problem with the fuel pump (loose wires for example) it brings down all the wiring instead of just the fuse.

 

Actually I'd start by examining the fuel pump wiring. Add a fuse if its connected straight to battery or connected to the main feed wire.

[datzenmike]

The fusible link should be at the positive battery cable. It likely is green and will be burned up. This is it's job, to to break a connection when the positive is drawing too much current, and to save the wiring.

[ggzilla]

But a new Fusible Link from Nissan

Nissan part number

25442-H2500 LINK-FUSIBLE,TYPE C

 

Or buy a generic from NAPA or Autozone

Use a "FUL 0.5mm2" fuse-link (20 gauge: 0.5 square mm)