my friend's '91 DX hatchback is overheating. the fan wont come on, and the coolant in the reservoir started boiling.

any idea what the problem could be? relay or fuse maybe?

thx in advance!

 

check fuses....there's a fuse in the fuse box under the hood to check and there's one under the dash. I'm not sure exactly which one. The one under the dash, it has a display on the cover, find the one that's for the coolant fan. Under the hood....shoot I forget which one. There is also a relay (cooling fan relay) that is screwed in next to your battery along the fender you can check.

My fan stopped working a while back, so I just ran a switch and bypassed the coolant temperature switch, which is located under the TB. It works fine now.

It could also be the fan motor I guess.

 

I would also check the water pump, and for the mean time run the fan straight. Honda engines don't like to overheat.

 

check the fuses, relay and follow the wiring to see if something got cut or disconnected first (easy and cheap to fix)...if that was the problem then i flush the coolant system (you should do this evey 30k miles to be on the safe side)

see if the fan comes on when the engine gets hot (keep an eye on the thermostat)...if it doesn't work then your thermostat may be bad...you can drain the system and remove the thermostat and check it to make sure it works...there are some tests listed in the helm manual...or just plunk down the money ($30) for a new one and install it

letting the engine overheat will blow a headgasket and warp the head ($$$)