Electrical Gremlins

1230 Views 7 Replies 3 Participants Last post by PimpMyPc, Aug 23, 2010

PimpMyPc

Discussion Starter · Aug 9, 2010

Been chasing down a few problems on the three door. Still won't idle but still a hoot to romp around town.

Here's the issue. As soon as you turn the key to the "ON" position, there is a split second or less buzz/rattle (think buzzing relay) coming from under the driver's side dash. It stops and you then hear the high pitch whine of the fuel pump for a few seconds like normal and then complete silence for a few seconds. Then the buzzing starts again from under the driver's side dash.

At the same time:
The fuel pump starts making a low pitch rumble/groan similar to the frequency that the relay or whatever under the driver's side dash is making.

The shift light starts dimly illuminating, but it isn't a low voltage glow but appears to be turning on and off at a high frequency (as if its hooked up to a PWM driver at a low duty cycle).

The Climate Control/AC relay under the hood will randomly buzz at the same frequency as the one under the dash. When I mean randomly, I mean it doesn't start and stop as the buzzing is happening, it will either buzz along with the under dash relay, or remain silent while the under dash one is tweaking out.

Any ideas what is going on here?

Save

1 - 8 of 8 Posts

PimpMyPc

Discussion Starter · #2 · Aug 23, 2010

While the battery voltage was still 12.3v with the key on, I checked the control wires for Relay 229. With the relay pulled out, I'm only getting 7.5v between any hot (positive) wire and the blue/gray wire that the PCM grounds out to turn on the relay.

With the fuel pump relay in, the main 229 relay starts buzzing immediately as soon as you plug it in with the key on. But with the fuel pump relay removed, as soon as you plug in the main relay, it clicks and a valve/relay/something under the hood cycles and so does something near the rear/fuel tank. A few seconds pass and the main relay starts buzzing again.

Also, unplugging the Climate Control/AC relay under the hood while its buzzing will cause the fuel pump to prime for 2 seconds, every 5-6ish seconds.

EDIT: Now the fuel pump is stuck on as soon as the key is turned on. Pulling the fuel pump relay stops it.

I also have about 5-6 ohms of resistance between pins 24-25 and the body ground right next to the ECU, but in one direction only. If I flip the red and black test probes, then there is 0 ohms of resistance.

See less See more

Save

PimpMyPc

Discussion Starter · #3 · Aug 23, 2010

FIXED......
Discovered there was no fuse in spot 28. Popped one in and BAM it lives.

Save

seriks1

· #4 · Aug 23, 2010

Bad grounds? Instead of checking voltage between poles on the battery, try + on the battery to the engine and chassis. In addition to the - cable on the batt. there's a smaller ground from the side cover of the tranny to the chassis a little behind the splash shield in the l/f wheelweel. 900 or 9-3, auto or 5spd, year,market????

Save

seriks1

· #5 · Aug 23, 2010

That's fast, I was still typing while you were fixin'

Save

PimpMyPc

Discussion Starter · #6 · Aug 23, 2010

I should have mentioned some specs lol.

This is a 1999 9-3 3 Door. I was getting the same voltage down by the relay box so I must have just said battery voltage.

Thanks for taking a swing at it. I was getting so frustrated trying to figure out what was wrong. All the grounds were good, getting power to the right places, no broken or shorted wires, it was killing me. I had it narrowed down to some weird ECU problem, and even tried a different ECU with no luck.

Here, it was a fuse..........................................................................

Save

Sleepy7666

· #7 · Aug 23, 2010

PimpMyPc said:
Here, it was a fuse..........................................................................

Worthless Noob.

Save

PimpMyPc

Discussion Starter · #8 · Aug 23, 2010

Sleepy7666 said:
Worthless Noob.

And who's the bastard that pulled the fuse out???

Save

1 - 8 of 8 Posts

This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.

Top Contributors this Month