74 620: Many Problems: wipers, wiring, horn, voltage regulator, etc.)

[Cardinal Grammeter]

Well, I got my engine to run on the 1-bbl carb that was cobbled on with plywood but I was really disappointed with just about everything electrical:

• Main fuseable link is gone along with the connector that comes off the battery cable.  The connector from the wiring harness is intact.
• Alternator does not charge
• Wipers do not work
• Heater fan does not work but it dim's the lights when I turn it on.
• Horn doesn't work
• Radio doesn't work
• Turn signals don't work
• 4-way doesn't work

The headlights and parking lights work.

 

Does anyone know the amp rating of that fusible link?

[flatcat19]

Start a build thread.

Not a new thread every time something happens with your truck.

[Cardinal Grammeter]

I am going to post my photobucket pic links in a "Build" thread and periodically update progress.

 

I was browsing the Electrical subforum looking for help with my electrical problem. 

 

I posted because of the widespread nature of the electrical outtage - its not simply "the wipers don't work." 

 

I'm thinking there could be a history of heater motors shorting out and blowing fusible links and then people hot wire the link and burn out some specific part of the wiring.  (In fact, the "Fusible Link" is a major topic all by itself.  Which I just learned.)

 

There is also conclusive evidence of a hot wire laying against the fuse cover - you can see where it melted into the cover.  Was this factory wiring or something added on?

 

I believe I am dealing with a corrupted electrical system.  There is evidence of incredibly inferior ignorant work done to this car - I'd say cobbled but that would give Cobblers a bad name.

 

I think I am going to need all the electrical insight and history I can find.

 

Do you think I should instead maybe have a "74 620 L16 4-spd with Myriad Electrical Problems" thread in the 620 model specific?

[ggzilla]

Go to your Nissan dealer and get a new fusible link. Plug & play.

 

Alternator won't charge is it is missing.

[datzenmike]

Because this is easy to get at and do... remove the fuses, unplug the fuse box and remove the two screws attaching it to the under side of the dash. Get a pail or container that it will fit into and submerge it in vinegar over night. Vinegar will remove all the corrosion and shine up the copper/brass parts. Rinse it well in the morning and replace the old fuses with NEW!!! ones. Fuses are not to be trusted by simply looking at them and old fuses are even worse.

 

Doing this will solve many electrical problems before you even have to trouble shoot them.

[Cardinal Grammeter]

Hey, thanks King Rat - will do!

 

Road Warrior:  I called my Nissan Dealer and they said the fusible link is NLA.

 

I think they use the Green 40 amp wire?  (next to the smallest link size, right?)

 

___________________________

 

Update, solved the fan problem.  Discovered how easy it is to work on the heater box.  Unclipped the pulled the front cover to fnd a long screw was lodged in the squirrel cage locking it up.  I got it out and the fan now works.

 

___________________________

 

Won't be doing more electrical for the moment, have very serious engine issues to attend to...

[Cardinal Grammeter]

Engine problem was a lash cap came off, so that was trivial fix.  So I'm back to electrical diagnosis.

 

Fan is working.

 

Want to do something about the Fusible Link and then the Wipers.

[ggzilla]

Road Warrior: I called my Nissan Dealer and they said the fusible link is NLA.

Try another dealer. Don't ask for a Datsun 620 part, ask for Nissan part number 25442-H2500

 

Green is only if a genuine Nissan link is used. Other manufacturers used different colors schemes. You can buy a $2 generic FL and crimp on the right connectors for the 620. Spec: FUL 0.5mm2 [0.5 square mm].

[Cardinal Grammeter]

Thanks Road Warrior! about the link.

 

UPDATE:  Alternator not charging:  The Voltage Regulator ROTTED OUT! 

 

On the bottom there are 2 power resistors.  The small one was soldered to terminals coming out the bottom of the VR.  THE TERMINALS ROTTED OFF at their base and the resistor was just hanging there.

 

So will update when new VR installed.

[Cardinal Grammeter]

Got a Niehoff WA-714 from RockAuto and it has the wrong connector on it - its a 6-pin rectangular and mine is the round 6-pin. 

 

By luck, I have both the 1973 and 1974 shop manuals and they seem to be the identical circuit diagram.

 

Further they show there were 2 regulators:

• 710:  TLIZ-58 rectangular
• 620:  TLIZ-79 round

 

So I'm seriously considering splicing the round connector on the new 710 VR.

 

The SM also has the pin callouts so the splice job would be trivial.

 

In the SM, there is no difference in any of the specs given for both VR's.

 

Has anyone done this before?  (This might deserve to be a separate thread for future reference.)

____________

 

EDIT:  I'm searching around for more info and finding other 620 VR's for sale that are also 710's with the rectangular connector.

_____________

 

EDIT2:  The round connector in my 74 has 4 male and 2 female pins.  I just looked at 75 VR's and they seem to all be round but it is difficult to find pics of the pins.  One pic I did find appears to show all 6 pins the same gender.  Also, the mounting holes are not as wide as the 74.

 

Seems like 1974 was right at the changeover and has the old mounting screw layout and the new, round connector?

 

Anyone run into this?

[datzenmike]

All years of 620 that use the external voltage regulator use a 6 pin regardless of which connector shape is used. Post a picture of your regulator and the plug.

[Cardinal Grammeter]

Here is a pic of the old and new regulators.  According to Shop Manual they use the same wire colors.  Splice the old connector on the new VR?

 

[ggzilla]

No problem . It will work. Or return it and get a B210 round-connector regulator.

 

[ggzilla]

1974 620 has a round connector, same B210

 

Photo

http://www.rockauto.com/catalog/x,carcode,1210105,parttype,4884

[ggzilla]

Seems 1974 was a transition year.

 

1973 it used the rectangular connector

 

1975 they switched to this round type connector

[datsunaholic]

My 74 (build date 3/74) has the rectangular one.  My '75 had the later round type just like 76-77.  I've never had one with the odd round (b210) plug, but I've gotten a bunch of those regulators over the years.

[Cardinal Grammeter]

I was just thinking how hard would it be to find the Rectangular Connector from a wiring harness? 

 

Then I could make an adapter and not chop up the new Regulator.

 

But it sounds like the rectangular was in the pre-74 models. 

 

Fat chance on that.

 

Actually, I think it looks like about 1/4" spade connectors - all I'd ahve to do is crimp (6) females onto the old VR connector and I'd have my conversion.

 

EDIT:  Looking at the pics, I think they may be too close together to do that.  However, I should be able to pop them out of the connector housing and then it would be a trivial matter to "splice."

[ggzilla]

Your new one is an early 610/710 regulator with the locking connector. Early 620 used a non-locking type.

 

Regardless of what colors the FSM lists, aftermarket regulators can use any color wires they please as long as the pinout matches.

 

The correct regulator is not rare even though it was only used one year. NAPA carries it part number Echlin VR525

[Cardinal Grammeter]

I'm going to make an adapter cable.  Female .187 blade connectors will do the trick.  I'll use an insulated for the centers so the corners can be un-insulated.  Then tape it all up to protect from weather.

 

I checked the wire colors and they coincide with the Shop Manual and the old regulator.  Haven't checked the pinouts, but I'll bet they are correct since the colors are.

[Cardinal Grammeter]

HORN Fixed - Loose Horn Pad Contact Screws: :)

 

Horn didn't work.

 

Turned out the Contact Screws in the Horn Pad had come loose - both of them!

 

All I had to do was tighten them up and I took a Cratex point to the stationary copper contact (built into the steering wheel) and the Contact Screw heads.

 

Since both had come loose, I'll bet this is a common failure.

 

Had to also more the horn adjusting screws around to get them working.

[Cardinal Grammeter]

WIPER MOTOR:  Wrong Pin Outs, Only Low Speed...???  WIPER SWITCH Contact Tarnish was the problem!

 

was really stumped on this one.

 

What they did: 

• LOW:  nothing
• HIGH:  very slow (seems like low speed)
• OFF:  they dock properly

The Wiring does not agree with Shop Manual and the Wiring Harness:  (Note both 73 and 74 Shop Manuals are the same)

 

EDIT:  Turns out the 73 shop manual has contradictory information:  They show a YELLOW wire in the picture of the connector, but in the schematic, they show a LY which is a Blue w/Yellow strip.

 

The 74 shop manual corrects this error.

 

The connector is correct:  a 2x3 rectangular with an empty corner position, however the wire colors do not agree with the shop manual and do not agree with the wiring harness:

 

From the Shop Manual:

 

L/W BLU BLK

--- YEL L/R 

 

This does NOT agree with my wiring harness colors:

 

BLK BLU L/W

--- YEL L/R  

 

The Wiper Connector is another configuration (No YELLOW!):

 

BLK BLU LL/R

--- --- LL/R,W

 

where LL is Light Blue, and /R,W is Red and White stripes* 

 

* both a Red and White stripe are unlikely, however it really looks like there are two L/R wires on the motor.  Since that cannot be true, right?  Looking carefully with an inspection mirror seems to reveal a white stripe too.

 

What really concerns me is the "wrong" position of the BLACK and the fact that the motor and harness match each other.

 

And the fact that the motor does NOT have they YELLOW wire suggests it is NOT the right motor for my 74.

 

So if I'm trouble shooting, do I go by the Position of the terminal or its Color?

 

EDIT:  Used wire colors of the harness to test motor.  LR was the 12v hot terminal as expected and B was the ground.  L appeared to be SLOW and LW was FAST (although they really weren't much different in speed.)

 

Then I tried to see if the Wiper Switch was working properly.  I couldn't get LOW which is supposed to connect L to B.  So have started removing switch.  Now it would be nice to be a little Asian guy (!)

 

 

Do I have the wrong wiper motor installed?

 

EDIT:  No.  Motor appears to be correct.  The problem was the Wiper Switch:  the solid copper contacts were tarnished severely.  So I opened the switch up and polished with Cratex again.  It is AMAZING how Datsun uses SOLID COPPER where contacts are involved.  None of that crappy stamped junk you find pretty much everywhere else.

 

EDIT:  Wiper Switch was the problem:  the solid copper contacts were tarnished severely.  So I opened the switch up and polished with Cratex again.  It is AMAZING how Datsun uses SOLID COPPER where contacts are involved.  None of that crappy stamped junk you find pretty much everywhere else.

 

 

_________________

 

And what really sucks is that the wiper switch is a washer type and it looks like the entire wiper system has been stripped off.  :mad:

[ggzilla]

Horn didn't work.

 

All I had to do was tighten them up and I took a Cratex point to the stationary copper contact (built into the steering wheel) and the Contact Screw heads.

Cratex point. First I've ever heard of them. How did you use them?

 

http://www.cratex.com/cratex-points-box-of-100/

[Cardinal Grammeter]

Using Cratex Points:

 

First, GREAT PIC!!!

 

Cratex is the name in rubberized abrasives which are used in manufacturing, machine shops, and other industrial operations.   

 

The points which you have shown have a hole in them - you thread them onto an arbor which is simply a threaded shaft.  (The color identifies the grit.)

 

Then you use them in a die grinder.

 

I was cleaning the contacts in the horn pad with Scotch Brite and it was taking a lot of work and also leaving some scratches, and then I thought I'd use the Cratex.

 

So I put a really fine finish on them.

[ggzilla]

Ah, that makes sense. I use a pencil eraser but it takes some time to buff the copper clean.

[Cardinal Grammeter]

Wiper switch pics added to Reply #21.