PCD's 74 620 progress/build up

[Pacific coast Datsun]

Thanks Gene. Feels good to drive it again. I think the next repair will be doing the front wheel bearings...inner & outer on both sides.

[Charlie69]

It runs!  What cuased the fusible link to fail?  I would carry a roll of fuseable link wire connectors and tools to repair it when it fails again and strands yo on the side of the road again.

 

99% of the time replacing a bad fuse or a bad fuseable link does not fix the problem because the blown fuse or fuseable link is the result of the problem not the problem.

[]2eDeYe]

Glad to hear it is on the road again :cool: 

[Pacific coast Datsun]

Charlie..the end of the fusible link wire simply came out of the connector..yeah I know lame !!

Thanks Redeye..I agree.

[Charlie69]

Mark is it still running?

[Pacific coast Datsun]

Yes she starrs right up..idles fine & has decent power. The bad thing is the motor is burning oil / white smoke coming from the exhaust.

& now I'll need to get the alternator rebuilt by I can still start it to move it around.

[Charlie69]

White smoke is not oil.  White smoke is usually water.  Do you have anti freeze in it?

[Pacific coast Datsun]

Yes I have a gallon of anti freeze in it & I topped if off with distilled water.

The smoke has an odor of oil in it.

[Charlie69]

Any progress?

[gene knight]

pcd: we need updates

[Pacific coast Datsun]

The latest madness is this. I had a dimming headlight issue & had to drive home with no headlights a few weeks back.

I tested the output at the back of the alternator & it

read between 12 & 14.50 amps .

I decided to put the boat alternator on the truck ..I got 2 blocks & the headlights dimmed again & the high beam switch wouldn't even function.

I'm thinking & hoping it's just the headlight relay

[Charlie69]

Check and clean all grounds. This is 99% of the time the cause of dim lights.

[Pacific coast Datsun]

I'll do that Charlie. The first time this happened I had to turn the lights off to.keep the truck from dying. I also had to.trickle charge the battery to get it started after swapping alternators.

[2wheel-lee]

Check to make sure you have a good ground from the engine to the body and from the body to the battery. I like to have a 3-way with 4 awg minimum: Battery to engine, battery to body, and engine to body. 

 

Make sure the ground wire goes to shiny metal where the paint is removed. Seal up after the connections are made. 

[Pacific coast Datsun]

Good info for sure thanks.

I'll report back what I find / have to do to fix this issue.

[Pacific coast Datsun]

Ok I added a ground strap from the block to the firewall & a ground cable from.the negative of the battery to one of the bumper bracket bolts & theres also a cable from the block to.the negative on the battery.

I then tried to get a reading off the Alternator using my multimeter with no results & yes I tried both red & black.probes on both Alternator plugs.

I ran the truck for awhile with the headlights & high beams on & they stayed bright.

Ill have to test drive it at night to see if the lights dim again.

[gene knight]

pcd: i have a 16 gauge wire from negative battery cable  to radiator hold down bolt and have no issues and a cable from block to frame

[Charlie69]

Mark I always have a frame to bed ground strap on the 520s and 521s,  Cant hurt to add one on your 620.

[Pacific coast Datsun]

Good info guys TY.

What was wierd that I wasnt getting any reading from the Alternator when I put the Multimeter probes on the Alt. plugs.

[Charlie69]

Might help to practice with a known working system to help understand the functions of your Multimeter.

[Pacific coast Datsun]

I was shown by a friend what setting to put the multimeter on to test the Alternator & got a reading off the old one.

If this makes a diffetence thd Alt I swapped on.was on the boat & its a 60 amp output.

[Charlie69]

If it is a 60 amp output then it has a built in regulator.  Is your wiring setup for an alternator with an internal regulator?

[wayno]

The 74 620 has an external regulator, so if the wiring is stock the alt will need jumper wires at the regular plug or need to be wired properly.

[Pacific coast Datsun]

Years ago I rewired it to accept an internally regulated Alternator.

[Charlie69]

Mark take your 2 alternators down to an auto parts store and have them test the 2 alternators.