521 issues

[sick620]

72 521.... So you need to know I just put a different motor in it... L16

 

before motor swap I was starting to have wiper issues they wouldnt work period...

 

the reason the motor swap is vital information for this thread is because the L16 I put in has a 105 amp chevy alternator...

 

So after motor swap I wired in the 105 alternator and Im pushing 14.5 volts all day...

 

after the swap....

 

wipers worked but they go SUPER SLOW...

brake lights DONT work....

turn signals DONT work....

headlights did work...

 

I hooked up a stereo in it and I was cruising to a town a few miles from me... the stereo was turning off and on so I decided to pull over and check if my ground wire was messed up or something... When I tried to leave truck wouldnt start.... alternator isnt charging battery! when I jump it and pull off postitive it dies...

 

Is it because my positive wire to alt is too small to handle 105 amps? where should I start looking to fix my issues!!??

[DanielC]

I also just got a project 521, and I bout is as a parts truck, with a rebuildable engine. the engine had compression of #1, 177. #2, 168. #3, 162. #4, 169. and starts easily, with a distributer just timed by eye.

See this thread:

http://community.ratsun.net/topic/30606-my-ratsun-datsun-521/

 

It also has electrical issues. Some are the same as yours. My headlights did not work, but mysteriously, last night, they came on. Same thing with the parking lights. I have not tried the wipers yet, I pulled the heater, to get the heater water valve to work.

 

The wiring in a 521 is pretty good, for a stock truck. Start adding accessories, and you can quickly go beyond the wiring capabilities. The fuse box is the weak link in the wiring for a stock 521. The spring clips are open to getting wet, and because the fuse end is a different metal than the spring clips that hold the fuse, they corrode, and slowly do not make good contact to each other, and then they get hot. Especially the headlight fuse, but this can happen to other fuses as well. When the spring clips get hot, they lose their tension, and that makes the connection worse, and they get hotter.

 

Some people remove the fuse box, and soak it in vinegar over night to remove the corrosion. make sure you rinse all traces of the vinegar off the fuse box before yo put it back, Vinegar is an acid, and will corrode metals just like water does, only much faster. Another option is to get some electrical contact cleaner, from Radio Shack, and use that to clean the fuse box.

 

The stock alternator wiring charges the battery through the positive starter cable, and a ground wire that goes from the frame of the alternator to the negative battery cable, at the place where it attaches to the cylinder head. There is also a black wire that goes from the frame of the alternator to one of the bolts that mounted the voltage regulator. The voltage regulator ground also has the ground wire for the headlights. This ground must stay in place, because if this ground goes away, all the electrical devices attached to either the cab, or frame, or bed of the truck will try to ground through the throttle cable, melting the plastic, and destroying the cable.

 

These alternator connections were good for a stock 35 amp alternator. They are not good enough for an alternator putting out three times that amount of current. You need bigger wires. It is like trying to get 500 gallons of water a minute through a garden hose to fight a fire, or using a single 1 inch pipe to handle the exhaust of a big block, high RPM V8 engine.

 

I would not run any accessories through the stock fuse box. You must supply additional fuses for things light high powered stereos. They will also need the ground side wiring looked at. The primary place to ground stuff is the cylinder head, or directly to the negative battery cable.

 

I also recommend adding additional grounds from the engine motor mount to the frame, jumping around the rubber part, from the frame to the cab, and from the bed to the frame.

 

Clean the fuse box. Add the grounds. Upgrade the alternator wiring. These are common to all electrical on the truck. Then we can start working on the details.

 

For the brake lights, you should have power to one side of the brake light switch at all times. Check that. For the turn signals, start with the four way (emergency) flashers. Make sure they still work.

[banzai510(hainz)]

Sick.

Since the new motor has a GM alternator I assume you shorted out the old volt reg connetor(2 jumpers) as everybody does when converting to a Internal volt reg alternator. Is this GM alternator a 3 wire or a 1 wire?

 

I persoanlly would have put the stock set up on the new motor to just make sure you got this correct in the first place. Than chaining everything at once.

 

most faults in 521 wiring are old fuses or corrossion in or around the fuse box

 

Is it because my positive wire to alt is too small to handle 105 amps?

Most people take the output of the alternator and route a thicker red wire to the battery+ cable at the starter. Its EZer to hide it there and at top of the battery(looks Cheezy)

[sick620]

I also just got a project 521, and I bout is as a parts truck, with a rebuildable engine. the engine had compression of #1, 177. #2, 168. #3, 162. #4, 169. and starts easily, with a distributer just timed by eye.

See this thread:

http://community.ratsun.net/topic/30606-my-ratsun-datsun-521/

 

It also has electrical issues. Some are the same as yours. My headlights did not work, but mysteriously, last night, they came on. Same thing with the parking lights. I have not tried the wipers yet, I pulled the heater, to get the heater water valve to work.

 

The wiring in a 521 is pretty good, for a stock truck. Start adding accessories, and you can quickly go beyond the wiring capabilities. The fuse box is the weak link in the wiring for a stock 521. The spring clips are open to getting wet, and because the fuse end is a different metal than the spring clips that hold the fuse, they corrode, and slowly do not make good contact to each other, and then they get hot. Especially the headlight fuse, but this can happen to other fuses as well. When the spring clips get hot, they lose their tension, and that makes the connection worse, and they get hotter.

 

Some people remove the fuse box, and soak it in vinegar over night to remove the corrosion. make sure you rinse all traces of the vinegar off the fuse box before yo put it back, Vinegar is an acid, and will corrode metals just like water does, only much faster. Another option is to get some electrical contact cleaner, from Radio Shack, and use that to clean the fuse box.

 

The stock alternator wiring charges the battery through the positive starter cable, and a ground wire that goes from the frame of the alternator to the negative battery cable, at the place where it attaches to the cylinder head. There is also a black wire that goes from the frame of the alternator to one of the bolts that mounted the voltage regulator. The voltage regulator ground also has the ground wire for the headlights. This ground must stay in place, because if this ground goes away, all the electrical devices attached to either the cab, or frame, or bed of the truck will try to ground through the throttle cable, melting the plastic, and destroying the cable.

 

These alternator connections were good for a stock 35 amp alternator. They are not good enough for an alternator putting out three times that amount of current. You need bigger wires. It is like trying to get 500 gallons of water a minute through a garden hose to fight a fire, or using a single 1 inch pipe to handle the exhaust of a big block, high RPM V8 engine.

 

I would not run any accessories through the stock fuse box. You must supply additional fuses for things light high powered stereos. They will also need the ground side wiring looked at. The primary place to ground stuff is the cylinder head, or directly to the negative battery cable.

 

I also recommend adding additional grounds from the engine motor mount to the frame, jumping around the rubber part, from the frame to the cab, and from the bed to the frame.

 

Clean the fuse box. Add the grounds. Upgrade the alternator wiring. These are common to all electrical on the truck. Then we can start working on the details.

 

For the brake lights, you should have power to one side of the brake light switch at all times. Check that. For the turn signals, start with the four way (emergency) flashers. Make sure they still work.

 

dude lots of good info thanks alot! :) Im soaking the fuse box in vinegar as we speak... Im going to try what you said... thanks!

[sick620]

Sick.

Since the new motor has a GM alternator I assume you shorted out the old volt reg connetor(2 jumpers) as everybody does when converting to a Internal volt reg alternator. Is this GM alternator a 3 wire or a 1 wire?

 

I persoanlly would have put the stock set up on the new motor to just make sure you got this correct in the first place. Than chaining everything at once.

 

most faults in 521 wiring are old fuses or corrossion in or around the fuse box

 

Is it because my positive wire to alt is too small to handle 105 amps?

Most people take the output of the alternator and route a thicker red wire to the battery+ cable at the starter. Its EZer to hide it there and at top of the battery(looks Cheezy)

 

Banzai its a 3 wire... like the one that bonvo did a write up on... what do you mean by old voltage regulator connector shorting out ( 2 jumpers) ? can you supply a picture of the connector you speak of? 2 jumpers? I knew to wiring so I dont know all the terms.... im going to try routing a wire to the starter like you say... how big of gauge do you recomend for that?

thanks for the info

[thisismatt]

Yes, the 521 fuse box sucks. Mine has the same issues with poor fuse connections. This is for the 510, but should easily lend itself to the 521.

 

[sick620]

thanks for the diagram matt

[banzai510(hainz)]

Use "thisismatts" drawing.just make a inch or 2 jumpers with the male blade connetors on there and stick it in the engine side of the harness as in the drwg. pull out the volt reg and save it incase you want to go back.

 

this should complete the circut.

Bovos writeup should mention about the jumpers.

I believe the 521 colors are the same as the 510.

 

I think 10ga wire is good. but youll still use the wire that was on the +sideAlt also hooked up

[DanielC]

If you pull the voltage regulator, you must put a bolt back into the inner fender to hold the ground lug on the body of the truck.

The wire going from the alternator to the starter carries the entire output of the alternator. If you have a 105 AMP alternator, this wire handles it. My opinion, go thicker than 10 GA wire. If this wire gets hot, and melts the insulation, not only will it short the alternator output to ground, but it will also short your battery to ground.

[DanielC]

Here could be another source of 521 electrical problems.

This picture is looking up, just to the right of the glovebox. If your cab has some rust in it, it is probably from some condensation forming on the inside of it at one time or another. It is likely that some condensation got inside these connectors. Today, I found at least one wire not making connection through these connectors on my truck.

[sick620]

hey thanks daniel :)

 

today I installed the freshly vinegar'ed fuse box... after it soaked for a long time I hit it with a tooth brush and its pretty shiney now... I ran a wire from alt to starter, I would like to install one larger because I think this ones about 10 gauge.... now everything on the truck works :) headlights, stereo, blinkers, brake lights, EVERYTHING :) Im going to continue cleaning up the wiring though,,..

[sick620]

ok so I just fixed the size of the positive on the alternator, I had some positive wire for a car amplifier it was only 12 gauge, I cut two pieces braded them together and put connectors on each end... everything is working on the truck... the window wipers dont seem to be going as fast as they should, and when I pull them twice I get the same speed as if I pull them once.. the stereo which is a 200watt panasonic deck (only hooked to one small speaker) is turning off and on when I pull the wiper switch or the heater fan switch,,, other wise the charging system is fine ( i can run headlights, brights, heater fan, stereo, and hazards all at the same time with little alternator draw),,, the stereo issues may be due to a bad ground still because its grounded to the underside of the dash where the previous owner had it....

[sick620]

so hey dudes I fixed my ground wire for my deck... im still having issues... I have it wired to stock fusebox along with my tachometer.. when I run any electrical at all (like blink to the right or left) my stereo shuts off...... run window wipers.... stereo shut off.... turn on fan.... stereo shuts off..... also if I turn on my turn signal my tach light flashes on and off with the blinker.... Is this just a issue because I have it wired to stock fuse box or is this a bigger issue with grounds like daniel was saying above?

[DanielC]

Remember when I wrote this?

"The wiring in a 521 is pretty good, for a stock truck. Start adding accessories, and you can quickly go beyond the wiring capabilities."

Believe it.

This is a picture of my fusebox, and the new wire I put on it.

The big fat white wire goes to the battery positive post. If you have had your fusebox off the truck to clean it, and looked under it, you will notice the three fuses by the white wire are tied together with a buss bar on the bottom of the fuse box. The small white wire goes to the ignition switch, and the ignition switch returns power to the black wire with the white stripe, by the fourth fuse down in the picture.

The big fat white wire carries all the power for the entire electrical system of a 521. For comparison, the extra fuse holder with the orange wire has 12 gauge wire. I am using this fuse to power an extra headlight relay, to remove headlight current out of the fuse box.

 

If you have your stereo wired up to switched power, with the ignition switch, that may be a problem also. All the switched power is carried by the ignition switch. Like the fuse box, it was adequate, for a stock truck, with stock electrical loads. And this was when the fuse box, and the ignition switch were new. They are 40 years old now. The ignition switch has to handle the wipers, turn signals, heater motor, stock radio, emissions relays, if they are still hooked up, and reverse lights. And probably some other stuff I am forgetting. I believe the 620 pickup added a relay to the heater motor circuit, to remove heater motor current from the ignition switch.

 

This is a picture of how the voltage regulator was mounted in my truck.

See the two black wires going to a lug, by the top corner of the voltage regulator? That was just hanging in space on my truck. It should be under one of the voltage regulator bolts, to ground things together. I think this also grounds some of the electrical stuff in the cab.

 

This is a picture looking up, by the outside of the glove box.

These connectors hook the engine bay wiring harness to the cab wiring harness. They carry power to and from the ignition switch, and they also have the ground wire for a lot of the cab electrical accessories. The contacts inside these connectors can lose contact.

[sick620]

ya I saw under the fuse box which side is constant and which side is ignition, and I knew that wire (large white on your setup) was the battery power to fuse box.. So you think its a good idea to get a bigger gauge wire for that? mines pretty small.. like smaller than 12 gauge probably... also should I hook up my stereo to where your orange inline wire is hooked up? and where is a good option to wire in my accessory wire for stereo and my tach? you know for ignition power (dont want tach on all day long haha) Thanks again daniel you are a huge help...