98 Grand Voyager V6 3.0 Bought new rad fans & pwm 'relay'. No go...

For some background, see my posts he https://groups.google.com/forum/#!to...er/d-nN1f4nVAo
Anyway I put in a new fan and a new relay, drove to work to warm it up good and...nothing. What next? Anybody know how to check the connector to the relay with a digital VOM (with the car warmed up, checking for voltages)? I haven't checked the fuse because the code #P1491 said fan relay. maybe I should check it in the morning. Doubt if that's it. This is driving me nuts AND broke. What do I do next?

"Mark Goodall" > wrote in message
...
For some background, see my posts he
https://groups.google.com/forum/#!to...er/d-nN1f4nVAo
Anyway I put in a new fan and a new relay, drove to work to warm it up good
and...nothing. What next? Anybody know how to check the connector to the
relay with a digital VOM (with the car warmed up, checking for voltages)? I
haven't checked the fuse because the code #P1491 said fan relay. maybe I
should check it in the morning. Doubt if that's it. This is driving me nuts
AND broke. What do I do next?

Grey/gray is B+ and is always hot even with the key off.
Black is ground.
Light green is fan output
Dark green is PWM in

Since the PWM signal is a switched ground I would get a cheap analog
multimeter and hook it to grey and dark green (once you are sure grey has
good power) then turn on the A/C or get the engine hot, its voltage reading
will show you the approximate PWM duty cycle, IE if the battery voltage is
14 and the meter reads 7 that is 50%. Digital meters don't do very well
here unless they have a duty cycle/dwell readout that can handle whatever
frequency the PCM puts out. If this test passes then jump grey to light
green and see if the fans run.

Daniel, the orange 40 amp fuse is fine. I'd run the test in the
morning, but all I've got is a digital VOM. I'll try to hustle an
analog from neighbors tomorrow. I'm I even asking the right questions
anymore?
Mark

"Daniel who wants to know" > wrote in message
...
> "Mark Goodall" > wrote in message
> ...
> For some background, see my posts he
> https://groups.google.com/forum/#!to...er/d-nN1f4nVAo
> .............................................)? I haven't checked the fuse
> because the code #P1491 said fan relay. maybe I should check it in the
> morning. Doubt if that's it. This is driving me nuts AND broke. What do I
> do next?


P1491 is Radiator Fan Control Relay *CIRCUIT*

The first step in the troubleshooting procedure is to check the Fused B(+)
circuit for an open (which woulod incloude a burned out fuse).

Yeah, SRN, I'm aware that it's a "circuit". Like I said, I checked the 40 amp fuse, and a week ago, I got +12v at pin 1 on the relay connector.
Mark

"Mark Goodall" > wrote in message
...
For some background, see my posts he
https://groups.google.com/forum/#!to...er/d-nN1f4nVAo
Anyway I put in a new fan and a new relay, drove to work to warm it up good
and...nothing. What next? Anybody know how to check the connector to the
relay with a digital VOM (with the car warmed up, checking for voltages)? I
haven't checked the fuse because the code #P1491 said fan relay. maybe I
should check it in the morning. Doubt if that's it. This is driving me nuts
AND broke. What do I do next?

{{

I'll give it some though but in the short you can wire the fan so it blows
when the ignition is on. I'd not do this in the dead of winter (then again
maybe I would is it ment getting home) but in Summer I have and run it that
way until the part came in.

Thanks, guys. I'm not going to bypass straight to the fans/ battery/ fusebox, because here in NW Indiana we have to
pass emission tests to renew plates and registration. Check engine light's an automatic failure.
I haven't done the test still gotta find an analog VOM. I've got +12v to the relay connector and good ground, so when I run the test if it fails, what do I do next? What am I missing? Temp sensor? My dash temp gauge works fine. Is it possible (God forbid) that it's the expensive computer gizmo that runs everything? I need to figure this out pretty quick. Any help is welcome.
Mark Goodall

My wife's picking up an analog VOM for $20 at the Shack, but she won't be back til 2 am. Meanwhile I'm going to go over everything and see if I
missed anything. (for instance, even though the fan's new, I haven't checked it with the battery.) Thanks to Steve N. for the troublshooting guide.
Can anybody tell me where the PCM module is physically located)
Thanks, everybody. Mark Goodall

"Mark Goodall" > wrote in message
...
> > Can anybody tell me where the PCM module is physically located)
> Thanks, everybody. Mark Goodall

For the PCM location check the inner left fender well next to the Power
distribution center box.(which is next to the battery.

"Mark Goodall" > wrote in message
...
> > Can anybody tell me where the PCM module is physically located)
> Thanks, everybody. Mark Goodall

This scan is out of the 2000 diagnostics manual. Location should be the same
as the 1998 model

http://i5.photobucket.com/albums/y17.../Scan10095.jpg