Help! Q45 Electrical Problems!!!

[youngq45r]

Ok. Question for all you Q45r's out there. I've just picked up a 1991 Q45 for real cheap from a friend of mine. Hears the background: he was getting the car all washed up for the weekend and he washed the motor with the hose! (i know, stupid but whats done is done) he started up the car and it ran fine. He shut it off and it never ran again. That was about 11 months ago. it will spin over but no spark. theres also no juice to the coil packs, or the computer packs (power transister units) I've been poring over wireing diagrams, tracing wires. i now know the whole engine control harness and engine controle sub-harness almost by heart. Got any ideas? Could it be something to do with the securety system? The kid i got it from didnt have the remote for it. I need help so im comming to you guys. Has anyone ever encountered this before? any help would be awsome. Let me Know. Thanks

[Bwana]

I'm going to move this over to the Q forum. Much better chance of getting a quality response there.

Welcome to NICO!

[Q451990]

As far as I know, the security system disables the starter - so if you're getting the engine to turn over - I doubt it's that.

This is a tough one for sure... do you have the FSM (Factory Service Manual)? If not you can download the '94 manual at http://www.phatg20.net - but there are some pretty significant electrical system differences in some parts of the car. Not sure as far as the ignition system.

Heath

[qsiguy]

If you are sure you have no power to the coils or transister packs the first thing I'd be checking is the main fuses in the fuse/relay block under the hood. Also there should be a couple smaller main battery wires coming from the battery, make sure they all have power. Obviously, check the battery cables really good. Just because it cranks doesn't mean all the cables have power.

If you have good diagrams for the vehicle trace back the power source for the coils and/or transister packs and find out where it lost power. Process of elimination should allow you to narrow it down.

Are you missing power on anything else you can find?

Oh, and I agree with Heath, I don't think your security system is the problem. One exception is if it's got some kind of aftermarket immobilization system on it.

Let us know what you've checked so far and what equipment you have for testing and I/we should be able to assist further.

[youngq45r]

OK. I WENT THROUGH WITH ELECTRICAL CLEANER AND CLEANED EVERY ELECTRICAL CONNECTION IN THE HARNESS. ALL THE WAY BACK TOO THE FIREWALL. I ALSO CLEANED THE WHOLE FUSE BLOCK IN AND OUT. NOW IM GETTING BETWEEN .25 AND .75 VOLTS GOING TO EACH COIL. I GET ABOUT THAT MUCH POWER GOING INTO AND COMING OUT OF THE POWER TRANSISTERS ALSO. THEN IT GO'S INTO THE FIREWALL SO I HAVNT CHECKED ANY FARTHER BACK. I DONT HAVE A TESTER THAT CAN CHECK THE VOLTAGE GOING OUT OF THE COILS BUT IM GUESSING THAT IT IS NOT GETTING ENOUGH POWER TO ACTIVATE THE COILS. DOSE THAT MAKE SENCE? I DO HAVE REALLY GOOD WIRING DIAGRAMS, I GOT A CD THAT COVERS ALL Q45'S FROM 1991 TO 1996. IM USING THE 1994 SECTION BECAUSE THE GUY SAID IT WOULD BE CLOSE ENOUGH FOR WHAT IM DOING.

I ALSO NOTICED THAT MY COMPUTER IS REMANUFACTURED. COULD A BAD COMPUTER NOT PUT OUT ENOUGH POWER OR SOMETHING? I DONT GET IT REALLY. IM JUST THROUGHING OUT IDEAS. ALL OF MY OTHER ELECTRONICS WORK FINE (SO FAR). LET ME KNOW.THANKS.

[grantfc]

just so you know your not alone, I have a 1990 q45 with the same problem, still working on. The motor turns everything works fine, but the brown with yellow strip wire coming out of the ignition relay behind the ecu is getting no power at all..... mine started with the starter turning over by itself...no key in ignition, then went to h--- from there still working on!

[youngq45r]

YES!! i mean, sorry for your problem but im glad im not alone. What started your problem? Water? Nothing?That was the next thing i was going to do was check that relay. Also the one by the fuse block under the dash driver side. Are you getting a small amount of power to coils as well?

[qsiguy]

Easy on the CAPS LOCK We need to take a little step back first. How are you checking for power on your ignition coils? Each coil will have a 12V+ wire and a signal wire that comes from the power transistor unit. If you are putting a multimeter between the two coil input wires you won't see 12 volts even if the car is running. The signal wire is a pulse telling the spark plug when to fire. To properly check for power at your coils you need to ground your multimeter to the neg terminal of the battery or chassis ground and probe the 12+ lead to the coil wire(s). One of them should have 12V+ when the ignition key is ON. If you don't then you need to check the Ignition Coil Relay to make sure power is making it past that and that it is switching on/off with the key. There is a fusible link near the battery that supplies power to the ignition switch and the coil + of the Ignition coil relay. I have to assume this fusible link is ok since the car will crank and this link supplies power for cranking as well. If you pull the Ignition coil relay out one lead should have constant 12V+, one lead should have 12V+ that turns on with the key, one lead goes to the coils and the last lead is switched ground that comes from the ECU pin 16. This switched lead also turns on the ECCS relay so if there is a problem with that ECU output the ECCS relay would also not turn on.

The transistor units get there 12V+ from the ECU output so they won't have power on then unless the car is cranking or running.

Below is an image of the circuits I'm talking about with some markings of where you should check.

[elwesso]

Just wondering, but have you checked the spark the old fashioed way (take a plug out and ground it against hte INTAKE MANIFOLD)?

[youngq45r]

Yes, i am grounding it to the negative post on the battery. I'm only getting .25 to .75 volts on two of the 3 wires. nothing on the third (ground) i know im not supposed to get anything on the ground (duh), but if im not getting 12 volts then i should check the relay? Which one? The ICR behind the ECU or the one under the driver side of the dash? I also tried the volt meter on the power transister unit while cranking over the motor. If im not getting 12 volts there then could it be the ECU?

And to elwesso, i did not personaly do that, but the previous owner did. Nothing.

[elwesso]

Look at this diagram, it is the main power diagram, ignore the MAF diagram below it.



Id pull the ECU out and see if the ignition relay is coming on. The ignition relay is the one on the left, behind the ECU.

Have you checked the codes to see if youre getting a code 21 (ignition signal)? I want to know if you're getting 21 before we proceed...

[youngq45r]

i dont think im getting a code. i don tsee a check engine light... oh. that light wont come on untell the car starts. Uh... i don thave a code reader for this car. If Im gonna get one Im not gatting a piece of crap. Where can i get a good reliable one?

[grantfc]

getting power to the relays, but nothning to the coils.....not sure what started it. I replaced my starter when it went bad, drove it for a week, wnet to the store for about 15 mins. came back out and the car was trying to start by itself....pulled the hazard fuse under the hood and i could start the car, so i took off trying to make it home. Got about 3 miles from home and the car died...just stopped running....after a $87.00 toing bill for exactly 3 miles and 15 mins..still no idea what is going on.....

[youngq45r]

OH. Wow. Scary thought. Keep me posted.

[grantfc]

would it be rude to jump in and ask a question about mine as well..same problem!

[grantfc]

you got it

[elwesso]

i dont think im getting a code. i don tsee a check engine light... oh. that light wont come on untell the car starts. Uh... i don thave a code reader for this car. If Im gonna get one Im not gatting a piece of crap. Where can i get a good reliable one?

The CEL wont come on for mayn codes. Take the ECU out and check the codes manually, its not hard. Plenty on this, you dont need a code reader to read the ECU codes! Not as easy hooking a code reader up but its not hard...

would it be rude to jump in and ask a question about mine as well..same problem!

Normally I like to handle things seperately but if its exactly the same and we keep it relavent to the topic in quesiton, it can onl yhelp. Go for it!

[grantfc]

i understand. i think you already answer my question....i will use this diagram to trace it down and let you know....thanks for your help!!!!

[grantfc]

do i do a search for manual code read? is that where i will find out how

[youngq45r]

Still New Here. How do you manualy read the codes? Got to go to class. let me know+ any other ideas you come up with. i'll check as soon as i get the chance. Thanks for everything.

[elwesso]

http://www.nicoclub.com/articles.php?id=60332

That article should help you. Maybe I should do a new article on how to do it.

[qsiguy]

.......but the brown with yellow strip wire coming out of the ignition relay behind the ecu is getting no power at all..... ...

How about the B/W (black/white) coming into the ignition coil relay. That is the supply voltage and it should have 12V+ when the key is ON. This s the relay behind the ECU as Wes described. If you don't have power coming into the relay on the B/W then you won't have any power on the BR/Y wire going out even if the relay is turning on/off properly. If you do have power on the B/W wire and the relay is turning on/off then the contact in the relay is bad and you need to replace the relay.

The wire at the coils that should have 12V+ when the key is on is the B/Y (black/yellow) wire. If you don't then check the voltages at the ignition coil relay.

[elwesso]

Basically to summarize, you take the ECU out, theres 2 scews holding it on. you may need to remove the large harness connector... I usually do because it makes getting the screws holding the ECU to the car easier. Then you pull the ECU out and hook the ECU back up to big blue connector.

Turn the car on (not running, just ign. on), and turn the small screw the only way it will go (i can never remember if its clockwise or counter clockwise, however thers a sticker on the front to tell you, the screw turns super easy), wait a second, and turn it back. The little red light on the ECU will start blinking as will the CEL on the dash. count the long and short blinks and that will tell you what you have.

Code 21 would look like this in terms of blinks

---------- ---------- -----

[grantfc]

done that with the screw and still nothing....light goes out.......but no blink

[elwesso]

Did you turn it back? When you turn it the one way the light goes out and then it will start blinking when you turn the screw back.

[grantfc]

cant remeber i will check tonight and let you know....god thank you both no i have a direction to go in

[grantfc]

yes sir i did and nothing

[qsiguy]

That wire gets it power through a 30A fuse in the fuse box under the hood. After the fuse it's a W/B (white/black) wire an before the fuse it's a B/Y (black/yellow) wire to the fusible link holder and from there it's B/W (black/white) to the battey + terminal on one of the two smaller wires coming from the B+ terminal that are plugged in. It's got to be loosing power somewhere in that area.

[qsiguy]

Here's the path it takes so it should be pretty simple to find out why you don't have power to your ignition coil relay. Not sure which 30A fuse that is but just check them all, it may be labeled "Ignition" since it supplies power to the ignition switch. If they are all good check for power on both sides of them. Check those fusible links as well and where they connect to the battery and the connectors themselves.

Did you have power on the W/B wire? That one should be hot all the time if the 30A fuse is good and it's source is good.

[grantfc]

first of all for what it is worth......you are a great help i have power to the b/w but not to the br/y? changed the relay still nothing. can not hear the relay click lick normal. if i take a test light and test the gray/red wire on either the ecu or ignition relay the ignition relay yo can hear click! i am wandering if the ecu is fried? i will take the diagram and try it this evening and let you know in the morning thanks again for all your help!