Rad Fans run with no key on cold engine

[OR VietVet]

The unit you unplugged, is it the one at the driver's side front under or near exhaust manifold? If that is the case, that one will not make the difference. That is the SENDER for the gauge. The sensor for the computer is in the other location that I sent the link for. On the intake on front area on passenger side of throttle body. When you take the air pipe off you should be able to access and unplug there and when key is on it may set a code for that.

 

[wifes_truck]

ahhhh ok cheers yes that was the one i un-hooked. i will check the other one.

on another note I found this... will be looking at this also. cheers will up date.

""
Problem fixed. There is a box just under the battery next to the radiator. It has two plugs with an extreme amount of wires held in place with a 6mm bolt. I pulled and to my surprise the plug in was wet and the bottom few male pins were corroded pretty bad. The male side has a blue cover over the pins. I removed the cover to have better access to cleaning the pins. Once uncovered ,the bottom pin looked to have some kind of growth that may have been touching the metal casing and possibly causing a short. Cleaned well with contact cleaner small wire brush contact dryer and then electric grease. Note: the gasket goes on the male plug side.""


Read more at: https://www.obd-codes.com/forums/viewtopic.php?t=15461
Copyright OBD-Codes.com

 

[Joseph Garcia]

Somebody here can get you a picture of the wiring diagram, or can tell you where you can go to find one.

 

[OR VietVet]

That sounds like may be the problem. That corrosion comes from battery leakage. Poor place to mount that anyway. If is the problem and you clean and fix it, I would figure out a way to cover and protect it. If you unbolt and clean, I would unplug all and check for corrosion inside the pins and connector housing.

 

[OR VietVet]

Somebody here can get you a picture of the wiring diagram, or can tell you where you can go to find one.

That is why I like ALLDATAdiy.com but I know there are other free sources for the wiring diagrams.

 

[wifes_truck]

OK... I figured out the problem....

1- stuck a trouble light into the pos end of the fan plug and grounded other end. no key light on. (easier to use than having fans blowing)

2- opened up the relays again to double check. top (alone relay) controlled the light, unplug plug it in. light went on off.... other relays did nothing.key on off no difference except the light stayed off.

3- decided to next try the ^^^ above idea.... took off neg bat cable and took off the PCM cover....

4- started to unscrew the first bolt to the point that the harness was loosened off. jiggled and wiggled it, then screwed the bolt back in to tight and wanted to see if that made any differences.... secured neg cable back into batt

5- Test light stayed off .... plugged into the fan .... no running fan

The wires going into the PCM? at the connections were loose or needing a jiggle.

I didn't completely take the plug out.

Problem solved

Thank you all for your support. I am sure there will be new problems arise as she loves her truck and I doubt think she is getting rid of it anytime soon. As she bought it 2 years ago after a hard search for it. first major problem that we have encountered.

cheers all ...

 

[OR VietVet]

Glad it got taken care of and for close to no cost. I would still get in there and inspect all connections for corrosion and tight and clean and even get a cover on it, but your call.

 

[wifes_truck]

there is the big PCM box cover on it, (pain in ass to remove) the whole connection plug seemed so neat and dry that I just figured why open a can of worms by fully opening it up. By wiggling the plug in and out a few times seemed to clean the connections enough to re-seat the pins.

If it happens again I know what to do to fix it.

Just a strange thing to happen and was wondering how common this problem is. First I have heard of it.

cheers and thanks for the help.

 

[OR VietVet]

Do you live in an area where they use salt on the roads?

 

[wifes_truck]

Vancouver bc area, they brine the roads with "god knows what" some watery mix of ??? could be a salted mix. the whole area seemed so nice and clean and dry that is why I didn't fully pull the plugs apart. And I guess the wiggling was just the right amount of play to "clean" the connections. as i said will keep an eye on it.