92 accord. Will not start. Main relay will not click. I trouble shot relay bench ck out of car cks good. When I do main relay ck with it in the car #6 I get no voltage when I go to start on the ignition sw. #8 I get no ground when going to start position. Could a bad icm cause this? Also on the wire print it showes a fuse after the ignition sw to the relay I could not find this fuse. The car will turn over but not start. The fuse is the third one down in the wire print.

. Test all under dash and under hood fuses with a test light or multimeter:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-3.html#post252145

. Perform the K-Test on the ECM:

K-Test: Remove the MAP Sensor connector and turn the ignition switch to ON (Position II). 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.

. Read the link below:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-7.html#post1245523

The problem does not involve the Ignition Control Module (ICM). However, it may involve the Engine Control Module (ECM), especially if the Check Engine Light stays on when the ignition switch is turned to ON (Position II).

OK checked map sensor its reading 5.03 volts. I tried all the other checks you mention all cks good. When I jump #5 and #7 fuel pump runs.

. Does the CEL come on and go off normally, when the ignition switch is turned to ON (Position II)?

. When was the last time the car started normally?

The cel comes on but does not go out. The last time the car worked was about a week ago. My daughter was driving back from school when it died.had to have it towed home.

The problem is with the ACG (ALT) (S) fuse, in the under dash fuse/relay box; ECM (perform the K-Test); main relay; or the ignition switch. Perform tests in that order.

Be sure to locate and test the ACG (ALT)(S) fuse--it may be in the SRS section of the fuse box. Use a test light or multimeter to test this fuse. If there's no 15 A fuse in the slot, there should be. All attention must be focused on getting the CEL to go out--that's the problem. After checking this fuse, check the ignition switch for wear, pitting, or melting:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-2.html#post224652

Did you clean the main ECM ground, located on the thermostat housing? If not, clean and apply dielectric grease.

Got it running. Sorry took so long to get back to you. It was the ecu. Took one out of another honda just to try it. It started right up. I got one on order from eBay. Thks for all the great help.

What was the K-Test reading at other times? I know you had 5.03v once--was it intermittent?

I am not sure if it was intermitten I only check it one time and it was a good 5.03 v not intermitten.

Sometimes, on a failing ECM, the K-Test will indicate 5.0 volts, while at other times 0.3 volts. Glad to see you got it fixed and I'm sure your daughter is too.

In order to restore "like new" reliability, and prevent another tow at some point, I recommend replacing the ICM and coil every 120,000 miles or 10 years, whichever comes first. I mention this because I remember the days of kids and car problems and them being away at school.

WHAT... THE... FFUUUUUCCCKKKKKKKKKKKKKK...

THE ACS ALT S FUSE... WAS GONE!!

How did this car run without it??

Why was it missing?

I've worked on this car before, replaced the dist. on it twice. And I am the only mechanic to touch it as far as I know... so w t f??

I worked with a Navy Seal extraction team member who's friend removed the ACG (ALT) (S) fuse on him as a joke from his Civic years ago. Someone has to really know these cars to know to do that. Let the investigation begin.