80bu

I have a issue with one fan not coming on. I have a new fan motor, relay and fuse. I have discoved I have power coming out of the fuse block to the relay with a test light. The blue wire from the computer is going to the relay and when I put the test light in the blue wire at the relay the fan kicks on, as soon as I take the test light away the fan stops. These are ls1 fans also. I have been driving this thing for a year with no problems. Jesse at wait4me did my harness rework.

Che70velle

iTrader: (6)

Your test light is grounding the circuit. Check your grounds.

gMAG

iTrader: (1)

Yes, verify the ground on the non-working fan.

80bu

I switched the plug that went to the non working fan to the working fan and it worked just fine. So how could it be a ground if it works on the other fan?

67Skylark

Sounds like the ground for the coil of the relay may be bad.

LS1MCSS

iTrader: (18)

Your pcm is putting out a ground signal. Is that how you have the wiring setup?

80bu

I use the fan signal from the pcm to the relay. How do I fix this issue?

psiconversion

iTrader: (5)

I'll assume this is a Gen III setup. Disconnect the relay and check continuity on the fan trigger wire (whatever color is going back to the PCM, I guess blue in your case) to the PCM Blue connector, position 42. If you have continuity, then either the relay is bad (which I doubt since you said it worked when the test light was hooked up), or the PCM is not telling the fan to come on. If there is no continuity then the wire is broken.

Jon
PSI

80bu

I have a new relay, I am going to dig thru the harness and check the blue wire from the pcm to relay. What happends if it's not getting a signal from the pcm? How do I fix this issue?

LS1MCSS

iTrader: (18)

Which relay terminal is it connected to? Better yet, how are all the wires connected at the relay? We can't really tell you what's wrong without knowing more about the way you have the wires connected.

Che70velle

iTrader: (6)

Ok, this setup worked fine for a year, right? You changed the motor, relay, and fuse because a fan stopped working. One fan still turns on properly, right? And when you change your plugs around, the new fan comes on, right? I'd take a look at the plug on the nonworking fan.

80bu

I have replaced the connector on the non working fan. I have the blue wire to the relay from the pcm. I have a hot wire to the relay from the fuse block that get its power from the battery. I have checked the wire and it is not broken. Can I take another wire from the pcm or can I control the fans another way?

G-Body

iTrader: (4)

From some of your other posts it looks like you may be running a truck 5.3L?

1. Is it a truck PCM? What year?
2. Did the fans ever work or has this been a problem from the start?
3. What pcm pin does the blue wire go to? (Most likely blue connector pin 42 or red connector pin 33).

80bu

Its a camaro 2002 pcm
The fans have always worked, I noticed I had a problem when i was blowing a fuse when the fans came on ,So i put two new fan motors and connectors and now only one fan works.
The blue wire goes to pin 42 blue connector.

Indyjc

iTrader: (1)

I'm having the same problem. I believe my issue is a broken wire or a bad pcm. I've been waiting for a hot day to see if it over heats, but so far it has stayed at 180. Good luck.

all juiced up

do i hook the computer negative to the fan negative and the key on to my 30 amp relay

mantycarguy

Wire it this way. pin 30 on relay to battery +, pin 87 on relay to fan +, pin 85 on relay to key switched +, and pin 86 on relay to pcm dark blue wire.

G-Body

iTrader: (4)

Try popping the connector off the PCM and ground the blue wire that goes to pin 42 at the pcm connector with the ignition on. If the fans turn on the problem is in the PCM, if they don`t turn on then its in the fan, the connectors or the relay.