Rewiring the Main Relay. 1990 Honda Civic LX

[Lefont Lafonte]

Hello Eric,

Recently found your videos on Youtube excellent work. I do have a question been that I can’t find anything on the internet, Haynes book, etc. I have a 1990 Honda Civic LX who was running find when I purchased it, but after a month the check engine light came on. I ignore the fact and kept on driving it like that. Well the car started to stall and I will just, while driving, turn the key on/off and will run fine for one minute or less. An aquaintance gave me a Main Relay and told me to install it. I told him that the connectors on my car will not match the part he gave me. Well he said cut the wires and use this connector (I have no idea about anything regarding cars) so now researching I went and bought the correct Main Relay, but the problem is bigger now, because I can only match 3 wires to the actual correct connector that will plug into the correct Main Relay. I’ve been looking for some directions but no one seems to be familiar with this situation. Any way you can help?

Thank you in advance,
Lefont

Topic

[dreamer2355]

I wouldn’t be modifying any factory wiring to install a incorrect component.

What symptoms are you experiencing exactly?

[Lefont Lafonte]

Hello Eric,

I agree, but I did not know anything about cars (I do now a little)and the person who told me to do it handed me a Main Relay with the connector hooked to it and stated that all I have to do is cut and rewire it. I did that, but it did not fix anything that was wrong with the car which was a check engine light and a horrible stalling every 4-7 seconds. I will continue operating the car while on the road by closing and opening the ignition switch and it will run and the back to the stalling. My problem now is that I have no idea which wire goes to the correct slot in the connector that plugs into the Main Relay. Due to me disconnecting the incorrect Main Relay along with the connector that came with it. I need help in knowing which wire goes to what slot. I have no problem with the black, green and two blue with white stripes, but there are some yellow ones that have long interval between the white stripes but and can’t seem to match them.

I hope this helps my explanation.

Thank you in advance, I think you’re doing a Superb! Job by posting all this videos online for free. You’re far better mechanic than the engineers running GM labs.

Leonides.

[Edwin]

First I would check what code the ‘check engine light’ (CEL) is giving you. I’ll post a link I came across for directions on how to obtain the codes for your car (pre- 1996/OBD1).

http://www.iequus.com/Content/Support/Manual/3173_ICCR_E_14JAN03.pdf

Next, try to post post a picture of the main relay you’re trying to use, as well as a picture of where you’re trying to connect it to. Don’t cut any wires, or tamper with anything before finding out what exactly is the problem.

[Israel Sepulveda]

hello I have a problem with my car because the car lose power When the car is turned off hot fumes have no leaks no oil leaks you change alternator wires inition do i change the inition Battery unless it happens to time recommend council :woohoo:

[Tom]

Honda’s, and especially ones from the 90’s, are notorious for having problems with the main relay. The TYPICAL failure is that the car will not restart when it is hot, such as having been sitting in the sun for a period of time.

The solution is to install a new (OEM) relay, OR . . . remove the main relay from the car, open it up, find the BIG solder joints on the relay board, wick away, or otherwise remove the old solder from them, and solder the joints again with a good quality electrical solder.

Usually, those solder joints are the only thing that goes wrong with the relay, and fixing those joints will allow you to use the relay for many more years reliably.

I NEVER suggest hacking up the cars wiring harness to install any component that doesn’t simply plug in, unless you are very experienced with wiring, and fully understand the electrical system you are working on, and it’s needs.

OP, at this point, it sounds to me as if you have already cut up the original wiring. I am all for DIY work, but I think you are in well over your head, and should find yourself a technician who is well versed in automotive electrical (and believe me when I say that MANY good technicians are not all that good at wiring) to sort out what you have done, and get things working properly for you.

[Author]

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