Dash Components: Identifying Electrical Plugs - 1984 Nissan 720

[bluexl]

Hey everyone, I just added an OEM clock and tachometer to my 1984 Nissan 720 dash/instrument cluster. I had already tested the clock, but I was still happy that it started working right away and it was easy to put both items in after removing the delete plates. Both plugs were there and connected without any issues. I put the cluster back in the truck, but I cannot get it to turn over. The headlights also do not turn on at all. Any thoughts on why this might be happening and which cable(s) might have gotten disconnected?

 

Also, can anyone tell me what these white plugs (see photos) are for? It seems like they need to connect to each other, but I am wondering what they actually control. They are located towards the driver's side corner of the dash, just above the hood release. These are the only visible plugs that I can find that are disconnected, but I believe they were already loose. As I stated above, my truck is not currently starting and the lights do not turn on when I turn the switch on. Looking for suggestions please.

 

Thanks in advance.

 

 

 

[bilzbobaggins]

Did you disconnect the battery to do this?

[datzenmike]

The headlights have their own dedicated fusible link and two fuses at the far right side of the fuse box. Should be easy enough to find where the power is and isn't.

 

Won't turn over? You mean the starter does not work?  Turn the key on, do the wipers work?

 

Mystery plugs... is one Yellow/Blue stripe and the other Black?

[powderfinger]

Just as a sanity check, measure the voltage across your battery terminals! I just took the entire interior out of my 720 and redid the whole thing. After putting the dash back in and connecting the instrument cluster I tried to start the truck and nothing happened. I just knew I had pinched a wire somewhere, even though it seemed highly unlikely, or knocked something loose, once again highly unlikely. I poked around and couldn't find anything wrong. I then checked the battery and sure enough it had somehow went bad in the week that it had been sitting there disconnected. Crazy coincidence and is likely not your issue, but I didn't think it was my issue either since I had just been driving the truck 7 days earlier.

[datzenmike]

What else did you do while removing the dash? Did you remove the positive battery cable?

[bluexl]

2 hours ago, powderfinger said:

Just as a sanity check, measure the voltage across your battery terminals! I just took the entire interior out of my 720 and redid the whole thing. After putting the dash back in and connecting the instrument cluster I tried to start the truck and nothing happened. I just knew I had pinched a wire somewhere, even though it seemed highly unlikely, or knocked something loose, once again highly unlikely. I poked around and couldn't find anything wrong. I then checked the battery and sure enough it had somehow went bad in the week that it had been sitting there disconnected. Crazy coincidence and is likely not your issue, but I didn't think it was my issue either since I had just been driving the truck 7 days earlier.

So, I took my battery to Autozone to have it charged turns out, the battery was bad and they gave me a new one. It is about 2 months old, so I did not think it to be the problem, but I will put it in after work and hopefully that was the issue. I am crossing my fingers!

[bluexl]

12 hours ago, datzenmike said:

The headlights have their own dedicated fusible link and two fuses at the far right side of the fuse box. Should be easy enough to find where the power is and isn't.

 

Won't turn over? You mean the starter does not work?  Turn the key on, do the wipers work?

 

Mystery plugs... is one Yellow/Blue stripe and the other Black?

@datzenmike, here is a photo of the mystery plugs. They are both yellow with a white line and thick red rings.

 

I have a new battery and will put it in after work and update the post.

 

Edited May 4, 2022 by bluexl

[bluexl]

13 hours ago, bilzbobaggins said:

Did you disconnect the battery to do this?

I thought I did because the dome light did not come on when I opened the door, but the battery was dead/bad. But I should have been more careful here. 

[datzenmike]

Everything in the instrument cluster is off and on a fuse anyway, so you might blow a fuse but not have a Chernobyl.

[bilzbobaggins]

More thinking about disturbing the fusable links/ terminals.  

[bluexl]

@powderfinger Well the problem WAS the battery. Car started right up. I didn't think of that at first because the battery was less than two months old, but that was the issue.

 

If anyone can identify the mystery cables with the yellow, white and red please let me know. For know they are still disconnected.

 

Thank you all for the help.

[datzenmike]

 There is one for California (called check point)  another for the power windows circuit breaker and one marked not used in that area. I wouldn't worry about it.

[bluexl]

1 hour ago, datzenmike said:

 There is one for California (called check point)  another for the power windows circuit breaker and one marked not used in that area. I wouldn't worry about it.

Thank you @datzenmike.