Main Relay Location

JenMon

New Member
Hello Honda lovers! I have a 1990 Honda Civic DX. Hatchback. 5 Speed. I need to replace the main relay and no one can seem to locate it. Can any of you help? Thank you!
 

linkdeezie

Respected
under the dash...driver's side...gray box...about 1 inch long by 1/2 inch or so wide...has part of the wiring harness plugged into it... and it's bolted to the car with a 10mm bolt
 

Okidokee

New Member
I have spent a whole day taking apart the dash of my Honda Civic EC9 1990 1.4L European model looking for the main (fuel pump) relay. There is no main relay in the location shown in the Haynes Manual or anywhere else that I looked, including behind the glove compartment on the passenger side. Finally, I called Honda Parts and they could not find it listed as referenced part so passed me to a mechanic. He told me that Civics of this vintage do not possess a main relay, which conflicts with the many listings for this part on the web, with the Hayne's manual, and with the comments of many forum contributors. Can anyone confirm if there is or is not a main relay in this vehicle? If yes, please tell me where it is. It is not to the left of the fuses, above the hood release and accessible once the coin holder is removed, which is what most people say.
 


Mr.Baker

Mr. Search
Registered VIP
5+ Year Member
10+ Year Member
I have spent a whole day taking apart the dash of my Honda Civic EC9 1990 1.4L European model
It would have helped if you had mentioned that BEFORE, since that's relevant!
D14 Euro models are dual carb, meaning no EFI, so it more than likely has a mechanical fuel pump, which is usually located near the back of the head, around the distributor.
 

Okidokee

New Member
Mr. Baker, I am most grateful for your advice. I am not member JenMon and did not create the thread. I simply joined it with my own problem so as not to start a new conversation on the same subject. You are correct, I have the dual carb model with mechanical fuel pump in the engine compartment to the rear of the distributor and valve cover. However, what I find confusing is the Haynes Manual for "Honda Civic 1984 thru 1991 - All Models". The first attached image taken from the Haynes Manual is of the above-referenced mechanical pump in the engine compartment, which is described in section titled "Carbureted Models". Then, in the next section, which refers to "Fuel-Injected Models", Haynes shows electrical connections to a pump mounted in the fuel tank. My car also has these connections, which is why I assumed that a fuel system relay must be present! If I am correct, the EC series was the one Honda hoped win over the European market; perhaps it wanted to offer the possibility of conversion to fuel injection?
 

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Mr.Baker

Mr. Search
Registered VIP
5+ Year Member
10+ Year Member
Mr. Baker, I am most grateful for your advice. I am not member JenMon and did not create the thread.
My mistake, I clearly did not read that, sorry about that.

However, what I find confusing is the Haynes Manual for "Honda Civic 1984 thru 1991 - All Models". The first attached image taken from the Haynes Manual is of the above-referenced mechanical pump in the engine compartment, which is described in section titled "Carbureted Models". Then, in the next section, which refers to "Fuel-Injected Models", Haynes shows electrical connections to a pump mounted in the fuel tank. My car also has these connections, which is why I assumed that a fuel system relay must be present! If I am correct, the EC series was the one Honda hoped win over the European market; perhaps it wanted to offer the possibility of conversion to fuel injection?
My guess is, Honda made all these cars the same from the factory to save on manufacturing costs, but when it came to actual options/trim/motor for the car, it got what it got. They may have been wired for PGMFI but not all got it depending on which motor they were getting.
 
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Okidokee

New Member
Yes, that makes sense. I was being foolish thinking that a main relay might be present despite the car being equipped with a mechanical pump. I guess I was seduced by the many internet posts saying that cracked solder connections on the main relay are the most likely cause of an old Honda engine suddenly cutting out while driving. So, now I must look elsewhere. Thank you for your time.
 


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