I just bought a 1991 CRX Si with the knowledge that one of the relays needed to be replaced. Unfortunately the seller was not clear enough about which one it is. When I took it to Honda's service department they could not recognize the part so I thought someone here could help me. I have a picture in its plastic case and one outside. The box is located under the dash on the driver's side.

 

its for the dimmer

 

Would that give me trouble starting the car? The car has trouble getting it started sometimes and the seller gave me that relay as the culprit.

 

It shouldn't give a problem starting the car. Have you checked the main relay?

 

That is for the dash light dimmer. what kind of trouble starting the car are you have it the not not turning over or is the motor turning over just not firing

if the motor is turning over and you check to see if you are getting spark and fuel and still not starting it might be the main relay
(driver side under dashboard right above the handle to open hood you should be able to see it some what and get a ratching box wrench in there to take the 10mm bolt out there are a couple of writeups on how to test the relay because its like 40 bucks from honda and alot of time the connections crack)

if the motor is not turning over and you are getting fuel and spark then it might be the starter relay. which is clipped up i think under the steering colum.

also check all your fuses under dash and engine bay.

 

its most likely the main relay, its up above the hood release handle

 

Alright guys, I figured out part of the problem. As a few of you diagnosed that was the dimmer relay. Problem was that the seller thought it was the "fuel" (main) relay. So I'm going to take a look at the correct one tomorrow. I'll let you know where I get with that.

Thanks to everyone for the help so far.

 

So I got a new relay and it seems be to starting just fine right now. Thanks again everyone.