eghatch9295

iTrader: (1)

so you tried another obd-1 AUTO ecu? since you said you've already tried a new main relay, id check your ignition switch. some of your symptoms point to a short in it.

Former User

Dial your multimeter to read DC volts. Voltage test 15A hood fuse 31 and 15A dash fuse 24. Do these tests exactly as described at the Test Fuses link in my signature.

gsr_b20b

if it was ignition wouldn't you think it wouldn't turn over?

gsr_b20b

After doing the fuse tests I had 12.39 reading at the under hood one. And 12.10 on the interior one, with the ignition turned to on

Former User

Voltage at BOTH test tabs of each fuse?

gsr_b20b

Oh that's just the one side. Ill go check the other side

Former User

Each fuse must have voltage at BOTH test tabs.

gsr_b20b

Yes they have the same voltage side to side of the fuse

Former User

^Good.

Unplug the main relay connector and measure voltage to body ground at terminal 1 [key off] and terminal 5 [key in ON(II)] in the connector. What is the voltage reading at each terminal?

gsr_b20b

Okay 1.632 on terminal 1 and 12.17 on terminal 5

Former User

Repeat the voltage test on terminal 1. If it repeats, you found the problem.

gsr_b20b

okay will do, what the heck is this for? I just found it coiled up in the wiring for the ignition, theres a bosch relay on the one end, some weird plug in, and the red wire you see leading up to the left has a inline fuse which goes to ground

gsr_b20b

After a retest on terminal one. It reads 1.767. What is wrong then?

Former User

Not sure. Could be part of an alarm system. Are any of the wires spliced to the main relay Yel/Wht wire of interest?

gsr_b20b

Oh okay. No there are no wires spliced into the wire for terminal one on the main relay

Former User

The Yel/Wht wire supplies voltage from 15A hood fuse 31 (ECU/main relay fuse) to the main relay. This wire is broken or interrupted somewhere between the hood fuse box and the main relay connector. You can locate the break and fix it or run a new wire. When you do, the engine should fire up.

gsr_b20b

Thank you so much! Your a life saver. Now my girlfriend will get off my back!

Former User

You can do a quick temporary test if you have a long piece of wire (~6-8 feet). Cut the Yel/Wht wire about 6 inches or so from the main relay connector. Twist/splice one end of the long wire to the cut Yel/Wht wire attached to the main relay connector. Attach the other end of the long wire to the (+) battery post. Turn the key to ON(II) and listen for whether the fuel pump now primes. If so, turn the key to START to see if the engine fires up.

gsr_b20b

Yes it fired up. Thank you very much for your help!

Former User

Congratulations. You're now an expert in troubleshooting and fixing car electrical problems.

norambos

mk378

It comes from the underhood fuse box fuse #31 and goes to the main relay. It should be live all the time, whether the key is on or off.

The original poster's problem seemed to be related to some aftermarket anti-theft system. If you have such a system be sure it is working, or cleanly remove it and restore the wiring to stock.