Cooling Fan Not Working 95 Transport

[red88gt]

I can't get the cooling fan to work in my 95 Transport 3800. The fan itself works when I apply 12 volts & ground. There is a constant 12 volts at the fan connection so I assume it's the ground that is disconnected when the fan is off.
I tried switching all the relays around without any success. I actually have 5 relays behind the headlight area so I'm not exactly sure which is which. The temperature gage works and it will overheat if you just let it idle. The fans don't come on with the key in the on position with the ac on either. Is there another temp sensor on this engine that I should look at ? It's the inside fan (puller ???)
that I'm trying to get to work (AC fan & AC itself doesn't work either but I won't worry about that until next summer). Thanks.
P.S. This thing just keeps on running with all of the relays out. Shouldn't it stall if the fuel pump relay's
out ?

[LMP]

"Shouldn't it stall if the fuel pump relay's out ?"
No...if it is already running, and there are even chances it can start without the relay..because in addition to the relay, the pump is directly fed by a switch in the oil pressure sender. SO once started, it will keep running, and if the oil pressure goes above a few psi on the starter...it might start also, but it would not have the primer fuel burst.
www.avigex.ca/xport/fuelcontrol_iac.jpg
www.avigex.ca/xport/coolantfan.jpg
WHen you say there is a constant 12V at the fan connection....you mean at the fan itself?...in which case it means your fan ground connection has gone haywire. The ground is permanent, and the fan is fed 12V only when needed...

[red88gt]

Yes, there is current present at the fan. If I splice a wire into the plug & ground it, it will run. I was going to do that & put a switch in under the dash if I couldn't fix it correctly. I thought it a bit odd that the ground side would be the one broken by a relay. I'll try just replacing the ground & see if it shuts off when it's supposed to. Thanks for the wiring diagram. Where do you think the ground is actually supposed to be connected ?

[LMP]

G106 Behind LH Headlamp
G100 Font of engine, above or next to Starter Motor assembly
The splices S106 S104 are areas of concern too.
Best is to splice a new wire as close to fan ground lead as possible and connect it to a known good body ground or known ground conductor..

[red88gt]

Thanks again. Like I said, I'll give it a shot tomorrow. I'll have a look at the areas you mentioned & if nothing is obvious, I'll just splice in a new ground.