My manual isn't available until Thursday (my parts store has it until I pay for it :) ) so... they're are 2 relays under the hood on the passenger side strut tower think a 899931 part number 12VDC/40AMP. The relays are exactly the same. The relay closest to the passenger side seems to kick on the aux. electric fan anyone know what the relay next to it does?

Loran Drellack

Those relays are identical and interchangeable. One is for the electric fan, the other is called the "radio suppression relay."

The "suppression" relay actually switches on and off the main power to the four fuel injectors. It does not provide the pulsing action -- the FI ecu does that by pulsing, or toggling, the injector grounds. The relay is nothing more than a remote power switch.

The reason for this, and for the strange name, is that the injectors toggle on 'n off at a rapid rate. This produces electronic noise that can interfere with radio reception, much as the ignition system can produce radio interference. Rather than having the injector power wires come back into the car and under the dash (near the radio and antenna lead), the power is provided under the hood and is switched remotely by that relay.

Resolder that relay and your fuel pump relay before one or the other leaves you stranded.
--
Don Foster (near Cape Cod, MA)

"The "suppression" relay actually switches on and off the main power to the four fuel injectors"

That explains why the car won't start with that one unplugged. :)

"Resolder that relay and your fuel pump relay before one or the other leaves you stranded."

Resolder? Is there a way to take apart the relay or is thisw done on the outside? Any pics of this being done?


Loran Drellack

Sorry, I fumbled the second picture of the resoldered relay...

"Resolder? Is there a way to take apart the relay or is thisw done on the outside? Any pics of this being done?"

The plastic cover snaps over the base of the relay assembly (the connector lugs stick through the base). Because this is an "underhood" relay, and will probably get splashed, the cover is sealed to the base. Bosch uses a thin bead of sealant, probably RTV, to waterproof the relay.

You can cut through this bead of sealany using an Exacto knife and then pop off the plastic cover.

After resoldering, snap the cover over the relay and reseal with RTV. I've done mine this way successfully. It costs $0, takes 15 minutes, has no risk, and is clean 'n easy work.

The first picture shows my suppression relay before soldering (note the cracked connections, and the second picture is after resoldering.