Electrical Conundrum

E

enigmas

Member
This is a follow up from the 'Overheated Lancer' thread.
http://www.auslancer.com/index.php?threads/overheated-lancer.10235/#post-233886 I got my daughter's little Lancer running again today. Took it for a a quick spin around the neighbourhood with my son in law Josh and grandson Jasper. It ran amazingly well from first firing up...tappets a bit noisy but that seems to be about it. the only untoward smoke was the greasy fingers and oil stains burning off the motor and components as it warmed up.

Getting to the point, none of us (adults) noticed at the time that neither the ventilation/heater fan, air con compressor, or the rear screen heater demister were operational, they seemed to be linked to one circuit.

I may have left a plug disconnected after the major engine overhaul but there's nothing obvious to find! The fuses all seem fine. Some of the relays are quite difficult to remove without damaging them ... (how are they locked in place) so for the present we've left them in situ.

If there's someone on the forum that has a good understanding of the electrical system in these Lancers' I'd welcome clarification on how to sort/locate this issue.
 
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This sounds like a fun thing to find without seeing it in person, one would have to assume that the problem originated from the engine removal and re-installation as it did not exist before this procedure.

I don't have a CE wiring diagram but from memory the power that controls all of the above does not run thru ignition switch, but instead the 12V constant power is negatively switched via relays as you turn ign key, this should in turn power circuit and control the BCM (body control module), a/c , ventilation power circuit.

This would be comprised of fuseable links/fuses/relays, i did read somewhere on an evo forum that an evo 4 (should be mostly same wiring i guess) that sometimes the connection wires that provide a constant source of 12v power to the (BCM) are the same colour wire and size as the switch 12v power horn relay (both red with a black stripe) so check they are not reversed, if you didn't touch them don't worry about them, just thought i would mention it in case you are getting constant low power readings at these points.

Check and make sure that all earth ground wires are connected and earthed properly (jumper wire to neg batt terminal to check), i'll see if i can dig up a W/shop manual with CE wiring diagram so you can trace power back thru the circuit until you find the cause, i guess someone on this club site has a copy of CE wiring diagram they can send to you or you can access from somewhere, it has got to be either earth connection in engine bay/fuse/relay/ or incorrect wiring connection in engine bay as chances of failure while doing the engine removal / rebuild anywhere else in the cabin area would be slim.
 
Thanks for your prompt reply wagonmaster. I actually didn't remove the engine...I carried out all the repairs in situ. Of course though, removing the cyl head, sump, conrods and camshaft belt drive means lots of stuff gets disconnected! The radiator was also replaced so that was removed, disassembled to fit the fans to the new unit. So lots of electrical plugs were disconnected. The battery and holder also came out too.

Your correct in assuming that it all worked prior to the overheating episode. Although, I wasn't there when the overheating occurred and it wasn't something to consider whilst focusing on the engine repairs. (Asking my daughter's what transpired would only give me a headache...not somewhere I need to go!) I don't believe that the RACV tow guy did anything mechanical or electrical prior to towing the car.

I'll check all the ground wires again.

The circuits that are non functioning are :
ventilation/heater fan,
A/C clutch & fan, (won't turn on)
Rear screen demister.

So these circuits must have something in common?

PS. I have a Gregory's WSM...I'll scan and attach the circuit diagrams.
 
Here's the pertinent wiring diagram.

IMG_20180122_084304.jpg


IMG_20180122_084025.jpg
 
For those guys that may be interested in this electrical conundrum...here's today's findings. I've included another image of the circuit with some annotations to try and clarify the problem.
20180122_193817.jpg

If you look at the circuit directly above...it illustrates how the heater/ventilation fan is switched on. The switch that controls this circuit (at centre dashboard) cuts in a ground/earth through a variable resistor (to one side of the electric motor) to create the various fan speeds. The other side is provided with 12v constant via a fusible link (no. 16. Where is it?) through the ventilation fan relay (this is situated in the interior fuse box under the DS dash board...behind the dashboard lighting switch.)
The solenoid side of the relay is activated by turning the ignition key to accessories or on. 12v then flows through fuse no. 21. (Where is this fuse located?...there is no number 21 fuse that I can locate!) This is also the circuit that provides 12v to the aircon switch.

Interestingly if I jump a wire between the W (white) and G (green) wires (note the pink dots)...the ventilation fan works at all speeds through the switch.

Based on this information the ignition switch is not activating the solenoid side of the relay. And yes...the relay functions perfectly when checked. From this I conclude that there's an open circuit (break) between the ignition switch and the relay pin that activates the relay solenoid....being the Blue/black wire (LB).

Given the above fuse no. 21 (10 amp) has to be under the dash somewhere!

So does anyone (electrical gurus please) know where this fuse is situated?

Note:
The rear demister doesn't work...this is also powered through fuse 21.
Fuse 21 (10 amp) appears to be the common thread!
 
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5BFB8835-B1D0-4F55-96D9-7F5AB3426C3F.jpeg

this diagram allegedly has it in the interior fuse box, but i’m gonna assume you already looked there? gregory’s has it up under driver’s side dash on the rhs, looks like the cover has demister icons on it?
 
Thanks Pelican...all the fuses, fuseable links and relays are sound! That's what's got me bluffed. I've checked the interior fuse box multiple times! What truly is irritating is that the fuse boxes fitted to this Lancer are generic parts fitted across the range of models. Several of the icons printed on the plastic cover are not relevant or fitted to the car. For example there are no numbered fuses on the interior fuse box...yet the 2 fuse boxes under the bonnet do have numbered fuses.

My take on the situation so far is that the power feed wire from the ignition switch (Lb...Blue/black is dead. The ignition switch is fed 12v from (W white) no. 14, 40 amp fusible link. Perhaps this circuit from the ignition switch is dead/faulty?

If so, using a jumper lead from W to Lb should power these circuits by effectively bypassing the ignition switch.
 
Hey mate,

I currently have my whole dash out and the loom in view, I will have a look for you and see what the issue could be. I just completed the climate control install, btw, blue-red is ignition, not blue-black.
 
Thanks for your assistance plethora. The wiring diagram I'm looking at is designated WD1 p.229 of Gregory's WSM no. 275. It shows a White (W) wire entering the ignition switch from no. 14, 40 amp fusible link from the engine compartment fuse & relay box. It also shows 4 wires exiting the ignition switch. These are BY, BW, LB and LW. LB (Blue/black) is what powers this circuit and goes to fuse 21 (10 amp)...it also runs off to the A/C condensor and cooling fan relays.
On this diagram there is no blue red (LR) wire!
 
enigmas said:
Thanks for your assistance plethora. The wiring diagram I'm looking at is designated WD1 p.229 of Gregory's WSM no. 275. It shows a White (W) wire entering the ignition switch from no. 14, 40 amp fusible link from the engine compartment fuse & relay box. It also shows 4 wires exiting the ignition switch. These are BY, BW, LB and LW. LB (Blue/black) is what powers this circuit and goes to fuse 21 (10 amp)...it also runs off to the A/C condensor and cooling fan relays.
On this diagram there is no blue red (LR) wire!
Click to expand...

I will test the same wire you did tonight, see if I get a light from my test light when i turn on ignition. However, funny thing is, the Blue-black (coming the wiring plugging into a sensor that is in the heater box) which i initially wired my climate control ign switch from had no power as per my post below:

http://auslancer.com/index.php?threads/climate-control.4790/page-2

however i will still try from the same point u described but i believe that will make no difference where its actually tested from as the coloring is the same and would not mean a different circuit.
 
Ignoring the bottom LB branch off to the condenser, the LB turns into LR after fuse 21. I would check LR to see if you get any power from that with ign.
 
That's a no! Take a look at post #5 (WD 8 above) ... the section I've marked with the pink highlighter. The ignition switch powers the solenoid side of the relay through fuse 21 (10 amp). That side is dead! All fuses in the internal fuse box (DS) are functional.

Note:
The jumper I used in #5 powers up the vent fan....but the solenoid side of the relay needs to be powered up for the A/C to function. LR derives power from fuse 21 through LB.

So theoretically fuse 21 could be blown...but where is fuse 21? The internal fuse box has no numbered fuses on this car. The engine bay fuse boxes (x2) do have numbered fuses!
 
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enigmas said:
So theoretically fuse 21 could be blown...but where is fuse 21?
Click to expand...

Forgive me if its a dumb question, but why not just look for the blown fuse instead of asking a couple of times? Theres the fusebox in the engine bay, and under the driver's foot panel. You've already halved your odds there, and so you've got about 10 fuses left to check. The diagram says its a 10a? That narrows it down to like 3 or 4...
 
I've checked every fuse of the car's 3 fuse and relay boxes multiple times. The fuse that control's this circuit is supposed to be inside the vehicle on the driver's side. Fuse 21 (10 amp) . Only there is no fuse 21! There is a 10 amp fuse there...but it's not blown. None of them are blown. So it's got to be something before the fuse box or behind it. Weird. The reason I asked repeatedly is that there may be another fuse a loner somewhere behind the dash between the ignition and where fuse 21 is supposed to be.

I think a lot of the difficulty in locating this problem is the Gregory WSM...it's not a Factory WSM.

I can easily bypass power straight to the ancilliaries if I've had a gutful, but I'd really like to find the culprit. I don't particularly want to pull out the complete dash array if I don't have to...hence my query.

I'll back track the LB wire to the ignition switch and check for 12v or open circuit next.

The car is not where I reside...so for today it's a matter of studying the various wiring diagrams thoroughly....presuming they're accurate to this car.

Still, thanks for your assistance with this...it's useful discussing the issue with someone...in case something has been over looked.
 
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You'll need to check the aircon relays then.

Shorting out the correct pins will activate the pump, and the fan, so you'll know if its the relay or another fault.
 
Thanks Donki...I'll do that...but I believe the problem is between the top relay in the internal fuse box and the ignition switch...12v for what ever reason is not getting to the solenoid side of the relay (i.e., it won't activate.) Jumping the other side of the relay activates the fan. So that circuit is fine. The A/C receives power (12v) from the solenoid side of that relay (currently dead)...so that is why it won't switch on.

I'll chase this circuit tomorrow.
 
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Actually easy way of working out which fuse, there is an order to the fuses based on fuse number (top down from the book).

pSg4mY1.jpg
 
Thank you pLethora...Great to know where/which fuse is actually 21. (You've obviously got a more comprehensive WSM than me). I've got 2 small grainy photos on pages. 206 and 207.
 
I have a gregeory's same as yours. I just noticed the pattern based on the photo's against what each fuse is for listed. :p
 
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