How do I test a voltage regulator?

[Fire_junky]

I need to know how to test a voltage regulator. If any one knows please let me know. I have been trying to fix my fuel injection system and now thanx to help from people in this forum I think I can but now another problem came up.

When I put a charger on my battery what I assume is the voltage regulator is humming, when I put the charger on start the regulator starts buzzing along with my distributor. The other day the engine ground wire that wasn't hooked up fell against my positive coil terminal. It was there for a couple minutes before I noticed it. By that time my battery was dead. So I figure the regulator is now screwed. What I assume is my voltage regulator is on the passenger side, under the hood, behind the fusible link. It is a 2 inch by one inch box with a round 5 wire plug. The numbers are pretty much worn but what I can read I think they are 25230 N4205 On my last post (where is accessory relay) some one gave me a link to down load the EFI Bible which is a great manual, is there one for the general electric system? Thnx for any help.

[sblake01]

Your 77 was the last of the externally regulated cars. My 78 has an internal regulator. I could scan a portion, or even the whole page, of the 77 wiring diagram that shows the v.r. if that would be of any help

[Fire_junky]

Accually I was able to figure out that problem but I still have the same problem. I can't get my fuel pump to get juice without jumping it and I can't get my injectors to work. I did everything the EFI bible told me to do. I did the test on page 69 and found that the terminal number 4 does not read the battery voltage like it was supossed to. It said if test is unsatisfactory then check wiring. Ichecked the wiring up and down and still don't know whats up. I have taken the fuel pump relay apart and manualy made point contact which turned my fuel pump on but not the injectors. I now know that that side of the relay is working correctly...wel maybe, but not sure about the other side. Once again does anyone know how to test a relay other than what the EFI bible sais? One last question, what is it that makes the ecu know when to give the fuel injectors power/fuel?

[sblake01]

Does the EFI Bible use the same relay test as the FSM? That is removing the fuel pump control relay and the fuel pump relay and testing them for continuity? The ECU sends the pulse to the injectors based on the various sensors, switches, and ignition coil.

[Fire_junky]

I'm not to sure what the FSM your refering to is. If you know of a download link for this FSM please let me know. Thanx alot.

[Bambikiller240]

FSM = Factory Service Manual (for the year of your particular car)

It is not available on-line. You would need to purchase a hard copy or a CD for your specific year.

[240ZX]

One thing you might want to check, especially after a direct short as you described, is your fusible links. Check the repair manual for their location. It is likely that they are fried!!! Just a little food for thought!