IC-pump keeps spinning

[bezerk]

So just installed my Shurflo pump.

it pumps real good, but it keeps spinning when the engine is out, even when i take out the ignition-key.

Can somebody tell me where to find the Relay??

Background information.

haven't done annything to the Circuit, just switched the + and -.
like it should be, and just using the same connection as Original.

Thanks

 

[ed hess]

its one the firewall.

ed

 

[bezerk]

So i have found the Relay, it''s on in front of passangerside.
but what does that relay do? it''s not only for the IC-pump is it?

and how do i make a shortcut? can''t make it with the wire that comes from the alternator, than it always runs.
Somebody knows something about this?
i wanna make a testdrive :wink:

Rene

 

[ed hess]

does it keep running if you unplug the relay.

if it does then something else is completing the circuit.

If not then subsitute a different relay into the socket. if it then continues the relay is toast.

Did the old pump run continually or was it dead?

do you have a meter to test wires?
ed

 

[bezerk]

Problem solved.

i geuss it was an coinsedence, As i was looking for voltage at the connecting point of pump and lines, i had it, but when connecting the pump, it didn''t had it annymore.
So i made an extra line at the +.
probberbly it made an connection (real coincendce).
So i taped of the line, and was driving for a while. after that the pump still didn''t work.
So i started to messure up the relay.
i geuss that part of the relay is dead, and i just made a little jumper.
So it finnaly works.
But what more does the relay does? i know this relay stands in connection with the relay at the driversside, feul-pump maybe??
So i made my 2wd testdrive, Dangerous i tell you!!!

Rene

 

[TyMeUp]

Circuit paths + ISO relay terminals.

'Main' circuit: power source at alternator BAT terminal (red wire) through an inline 10A fuse to relay large blade terminal (30) through main contacts (Normally Open). From relay large blade terminal (87) (orange wire) to pump connector.

'Control' circuit: Ignition feed side of fuse panel (pink/black wire) to relay terminal (86) through relay coil to terminal (85) then (yellow wire) to ECM where it is grounded on command from ECM.

If you splice a wire into the yellow wire and run that to ground, the pump will run whenever the ignition is turned on. You could also add a switch to this spliced-in wire to provide selective control (sw ON = full time; sw OFF = ECM control).

I agree with Ed, the relay contacts are probably welded together. If disconnecting the relay connector does not stop the pump, you may have the wrong wires connected to the pump or someone has modified the circuit.

If you can't easily get a new GM relay, the ISO relay pin numbers should help you construct an adapter.

 

[TyMeUp]

I had to go look this up.

The relay next to the pump relay is call a 'Turbo Boost Cutout Relay'. The ECM control for the 'Boost Control Solenoid' runs through the (Normally Closed) contacts of this relay.

The control circuit is grounded by the normally open 'coolant level switch' which is mounted in the heat exchanger radiator. This circuit is designed to sense when you have a leak that drains the intercooler. It is also wired to a light in the instrument panel.

When the 'coolant level switch' closes (due to low coolant), the 'Turbo Boost Cutout Relay' will open to cut the ECM control of boost. The 'Boost Control Solenoid' then closes so that all pressure is applied to the wastegate control. This will limit boost to base levels - (7-8 psi).

If you disconnect this relay, you will get base boost.

 

[bezerk]

That was alot of information.
i thought the IC-pump was steered by the groundwire?
maybe i misread something.

Annyway i have connected the IC+ wire (at the relay) to the ignition switch wire.
when i was fooling around with the jumper (with AMP-meter), i could here something buzzing, and when i disconnecting the jumper i heard that same sound again.

Just made a jumper, can't imagine i did something wrong.
It really pulls verry strong! (just put my propshaft back in).
and have more than 7PSI boost.

annyway thanks for the help.
and why does nothing of those circuits stand in the Workshop manual, or do they?

Rene

 

[ed hess]

page 41 in the wiring diagrams

ed

 

[TyMeUp]

That was alot of information.
i thought the IC-pump was steered by the groundwire?
maybe i misread something.

The 'relay' is controlled on the ground side. Relay then switches the hot side of the main circuit to the pump. The pump has a direct ground.

Anyway i have connected the IC+ wire (at the relay) to the ignition switch wire.

I would be careful here, the pink/black wire is a smaller gauge size. That same circuit also feeds all the computer controlled relays, solenoids, and the fuel injectors. If you overload and blow this circuit's fuse, you will have a complete engine shutdown. Better to replace the relay and jumper the yellow wire to ground.

The manual's wiring diagrams are very hard to follow. I recommend you use a set of colored hi-liters. Select a color close to the actual wire color and trace the circuit paths. The insides of most components are shown, so you can easily figure out what happens when a relay closes or power is applied to a motor.