1987 Accord LXi 4 door 5 speed

The A/C condenser fan wasn't coming on when the A/C was on which made the engine overheat in stop and go traffic during our recent heat wave.

I put 12v to each fan and they ran fine.

I checked the fuses and the #12 fuse in the engine compartment fuse box was blown. I replaced the fuse and started the car (it was cold). As it was warming up I turned on the A/C and both fans came on. I turned off the A/C and waited for the engine to come up to temperature. It finally got there and the radiator fan came on fine.

Then I turned on the A/C and no condenser fan - #12 fuse was blown again. I can't remember if the radiator fan stayed on. I think it did. I'll run the test again tomorrow to verify.

Any ideas where to start testing for a short?

Thanks
Paul

 

First off WELCOME to HAF.....

On the acords BOTH fans should come on when engine reaches normal operating temp or when the a/c is on.........

try to buy a 10-15 amp circuit breaker, it will save you a lot of fuses when doing electrical trouble shooting a short.........
anyho,,,, first off,, unplug the connector going to the cond fan and see if it still blows fuse ,, if it does not you got a shorted motor,, if it still blows the fuse , try a different cond fan relay, it is located in the underhood fuse box, if it still blows the fuse , you got a short in the wiring

but do the easy thing first,, unplug the connector at cond fan motor, start car, put a/c on,,if fuse does not blow you got a bad motor ..


let us know the results

 

Thanks for the reply

Last night I reran the test.

New fuse in the box; swapped the cond fan relay with the other identical one next to it in the engine fuse/relay box; engine cold.

Started the car and turned on the A/C. Both fans ran. They did cycle frequently - they'd stay on for about 10-15 sec or so then both turn off for about 10-15 sec. They continued to do that as the engine warmed up. When it finally got to operating temp and the regular cooling fan kicked on, the fuse blew and the cond fan did not come back on.

It seems like it's OK if it's just the A/C that's telling the fans to come on. If the A/C AND the thermostat are telling them to come on it shorts the cond fan somewhere.

So, having eliminated the fan and relay, it looks like I have a short. Any ideas where to start looking for it? That wiring harness is no fun to trace, and after 20 years, there are a lot of places that the insulation could be worn through. The fact that it happens when the cooling fan kicks in must narrow down where the short could be. I'll have to take a look at one of my other shop manuals to see if they have a more easily read electrical schematic than the factory manual I usually use.

Another sort of related question. I'm still running the old R-12 freon in the system which, obviously, hasn't been touched since 1995. It seems to run pretty well - it kept the car reasonably cool during our recent 100+ heat spell (at least until the fuse blew). I haven't done any pressure tests (I think that's coming next) but I did notice a lot of foamy bubbles in the sight glass when the compressor kicks in. Are there ever supposed to be any bubbles visable in the sight glass? Could that be why it's cycling so frequently?

Thanks for your help.

 

just watch out for black death.

 

try this..............start the car up,, unplug the connector at cond fan motor,,( driver side fan ).. put a new fuse in the fuse box,, do not put a/c on, let the engine warm up till the main fan comes on ,,when fan comes on chk to see if the cond fan fuse is blown ...........
If it is not blown let the main fan cycle a few times ,,, if cond fuse is still good,, plug in the cond fan motor connector and chk the fuse ,, let it cycle a few times ..

let us know what happen....

Also there should be no foam ( bubbles ) in the sight glass, system might be a bit low on freon,,