Ask Me Help Desk - Prelude won't start, fast clicking+flashing, no crank

About 2 weeks ago my car wouldn't start and I figured it was the main relay so I pushed it to a local shop, they diagnostic tested it and told me it was a faulty viper alarm system so they ripped that out and redid my wiring, started up no problem for about a week and a half, I drove the car about 100 miles to my parents house and on the way back about 20 miles in I got a check engine light, it was late and I had to get back for work so I just drive the 80 miles hoping it was nothing serious. I may have been wrong... I parked the car at home and popped the hood engine sounded normal wasn't overheating or anything. So the next morning I go to start it and I get this fast clicking noise coming from my driver side dash, no crank at all, also the lights on the dash are flickering including the check engine light. I tried the key in the on position about 3 times and on the 3rd time for about 20 seconds, I tested the battery and alternator, they are fine. I tried again today (the next day) and still same thing.

Any thoughts?
Thanks for any help in advance

. If the engine "cranks but won't start:"

If the Check Engine Light stays on, when the ignition switch is turned to ON (Position II), then perform the K-Test on the ECM. My thesis is that the ECM has failed (90% certain). The noise you are hearing is from the main relay, which is controlled, through main relay terminal 8, by the ECM. When the ECM begins to fail (cause), the main relay goes into cardiac arrest (effect).

The K-Test: Remove the MAP Sensor connector and turn the ignition switch to ON (not start). Using a multimeter, check for 5 volts going between the MAP Sensor connector's reference wire (+) and ground. As you look at the connector, this is the socket on the right. Really press the black test lead into a cleaned main ECM ground on the thermostat housing. If the voltage is low, it's probably indicating ECM failure. Most failed ECMs will record a fraction of a volt. To me, the K-Test is simple, elegant, and accurate.

Here's how to change the ECM yourself:

https://www.askmehelpdesk.com/cars-t...tml#post235038

. If the starter motor won't crank:

https://www.askmehelpdesk.com/cars-t...tml#post235560

Sounds like the starter may be stuck.

Quote:

Originally Posted by txgreasemonkey

. If the engine "cranks but won't start:"

If the Check Engine Light stays on, when the ignition switch is turned to ON (Position II), then perform the K-Test on the ECM. My thesis is that the ECM has failed (90% certain). The noise you are hearing is from the main relay, which is controlled, through main relay terminal 8, by the ECM. When the ECM begins to fail (cause), the main relay goes into cardiac arrest (effect).

The K-Test: Remove the MAP Sensor connector and turn the ignition switch to ON (not start). Using a multimeter, check for 5 volts going between the MAP Sensor connector's reference wire (+) and ground. As you look at the connector, this is the socket on the right. Really press the black test lead into a cleaned main ECM ground on the thermostat housing. If the voltage is low, it’s probably indicating ECM failure. Most failed ECMs will record a fraction of a volt. To me, the K-Test is simple, elegant, and accurate.

Here's how to change the ECM yourself:

https://www.askmehelpdesk.com/cars-t...tml#post235038

. If the starter motor won't crank:

https://www.askmehelpdesk.com/cars-t...tml#post235560

That sounds like a cookie cutter response, no offense. First off I'm a broke college student, I don't have a multimeter or anything beyond a fix-it-for-dummies tool kit. And you said: If the engine "cranks but won't start:". Its not cranking the starter at all, it just clicks and flickers dash. I figured my main relay was failing cause I've been having hard starts recently where if id drive a short distance then turn car off for 3-5 minutes then go back it will crank but not start, let it sit for 5 minutes then it starts no problem. Typical symptom of a failing main relay isn't it?

However if it is a failing ECU how much do those run $ for? And could I swap one out without any advanced tools? All I have is a ratchet set and some screw drivers.

I am offended by your "cookie cutter" remark. Maybe somebody else can work with you.

Quote:

Originally Posted by txgreasemonkey

I am offended by your "cookie cutter" remark. Maybe somebody else can work with you.

Sorry, it just seemed like something you copy and pasted from a response you gave someone else. I didn't mean to offend but the point of that response was to say your method of diagnostic isn't something I can readily carry out, I'm not a mechanic I'm just a student with a PoS Honda looking for an opinion so when I take it to the shop I don't sound like an idiot they can take advantage of.

The first order of business, when having electrical problems, is to ensure that the battery is good. The clicking sound you hear (from the starter solenoid or relay) is likely caused by a deeply discharged battery. I recommend that you remove the battery and place it on a charger, which many auto parts stores will do for free. This will tell you if the battery is really any good or not. Be prepared to buy a new one. Before installing the battery, clean the terminals and cable connections. This should also take care of the lights flickering on your dash. Get this taken care of and we can go from there, if necessary. A bad battery may be all that is wrong.