Hi All,
I have a new to me 93 cb7, f22a1, A/T, A/C that does not work(no fluid). Both cooling fans come on with the ign on, cold engine, A/C off and not running. I have replaced both fans (old ones were cooked), ohm tested A and B temp switches, tested fan relay in u/h fuse box,checked wiring harness for obvious tampering, swapped out fan timer relay(i hate working underdash, 6'-7" 265lbs... I just dont fit in there lol), and of course all the fuses. Any thoughts ?... ECU?

 

I'm a little bit confused.

Is the problem that both fans run all of the time?

 

Both fans run as soon as turn the ign on without starting it they continue to run after running and never turn off. They do not run with the ign off which if they did would be a clear indicator of a timer failure. Actually had 2 timers that my friendly wrecker let me have for a 10 bucks. car itself is in decent enough shape and I picked it up for free with a flat tire and an almost toast fuel pump, oem for a new timer was like $260.00 and 3 days from the warehouse. Any help at all would be surelly appriciated

 

I know you said you tested it but just for the heck of it. Remove the green two wire connector on the t-stat (lower hose connects to engine) and turn the key to on, what happens?

https://www.hondaaccordforum.com/for...similar-44973/ Somewhere in here I know there is a diagram of the cooling fan circuit.

 

I have tested with both a and b thermo switches disconnected at the same time and one at a time, fans still run. Remove the fan relay and one fan shuts down but the a/c fan keeps running. A/C is off ( no light on dash switch). Tried 2 different timers with the same result.

 

Update, when i pulled the rad fan relay from the fuse box the condensor fan stopped but the rad fan kept running.....

 

so after checking the diagram I think that there may possibly be a short in the circuit between the fan relay and temp switch A. nope seems ok guess i gotta go back under the dash.....oh joy

 

ok so I think after all of my testing that it is the blue wire from the fan timer to the ECU that is grounding the relays for both fans i wiil crawl back in under the dash and open that circuit if fans turn off then it is definetly the ECU?

 

Unplug the a/c pressure switch, then start the car. Do both fans run?

 

yes both fans are running, both fans keep running with every pressure and temp and clutch disconnected. the only way shy of pulling fuses to turn them off is to disconnect the relays. so i have eliminated all the mechanical switches and relays as being the problem. I have bench tested each switch both with 12v and tested resistance in each circuit through each switch and relay. they all pass with flying colors. Basically it boils down to the system being the equivalent of a 5 way circuit with the timer and the ECU in ultimate control. So to that end the last step I took tonght was to reconnect everything, went back under the dash and cut the solid blue wire from the timer to the ECU which I beleive is part of the ground controls for the relays. I believe but dont quote me on this that the blue wire sends a signal to the ecu to ground either the low power fan relay during a high temp, key off situation or both relays when asked to by either the cooling or A/C systems to run both fans when key is on. to that end i cut the solid blue wire from the timer but only the low power(drivers side) fan turned offthe high p[ower (passenger sde) kept running. So is it the timer at fault , or the ecu cause as far as I can tell its one or the other.
As a side note to all of this the cars heat gauge tends to get very close to the red line at a stoplight. I've burped the coolant and cracked the bleeder etc when I originally started this whole process and thats when I discovered that both of the original fans where toast. but I would like to at least get the electrical/cooling side of the system figured out before I tackle that issue.
Thanks again for all your help guys and if you have any more ideas please feel free to throw them at me. I must say that so far everyone I have met here has been very friendly and helpfull. Great forum and I will be sure to pass that on to my many Honda friends here in B.C.