why did the braker trip when i jumped the solid blue to the red yellow on the heater relay?

 

The next step is going to get nasty. See the attached jpg. It is of a plug on the heater case.....or real close.

The heater case, IF memory serves has a small harness on it that consists of the wires you've been playing with. Well those wires connect to a larger plug that looks like the jpg attached. That plug would need to be disconnected and then we can look at the wires on it.

I think I'll drop the heater case and take a look as to where it is. It's on the right side.....I think. I think we need to do this to find out why you don't have power to the relays. I'll get back to you in ??? thirty or so. I'll be busy tomorrow so I need to do it now.

 

did you have any luck finding that? stupid forum was down for a while...

 

The RED wire is ground is why the fuse popped.

For some reason your missing the power on the Heater relay (light green/black wire) that pulls the relay in.

Since you say the Meter fuse is good, then grab the wires on that relay, and follow them up and to the right. You'll see they end at a plug with the same number of sockets as I showed in the last post of mine. Pull that plug apart. Now on the side of the plug that is not attached to your blower unit, check the Black/Yellow wire for power. It's the second one over on the bottom like in the picture.

I bet it has batt power with the key ON. Nothing else has to be done but go to ON with the key.

So if you have it there, I can explain why you don't have it at the Heater Relay. It is because there is a fuse on the blower housing that is blown imho. So check that black/yellow and get back to me tomorrow or tonight.

The blower housing looks like the jpg attached when out of the car.

 

There is a fuse in a long piece of plastic in the area shown in the attached jpg. See if that fuse is good or not. Don't do that unless you don't find power on the black/yellow wire in the plug I mentioned in the last post.

 

can i get at that wire without pulling that whole box out?

 

It's on the firewall side of the housing. I'd guess ...no.

 

how hard is it to pull out? i see there is 2 10mm nuts/bolts at the bottom..what else holds it? i wont be able to pull it till tomorrow at the earliest

 

well the fuse is in the back but isnt the connector with that black/yellow wire that i have to test the one pictured in post number 54 in the second jpg all the way to the left? the 8 pin rectangle plug right near the 2 relays?

 

Yeah. For sure check that black/yellow wire. It has to have batt voltage with the key ON.

I made another mistake. That is not a fuse on top of the housing. It's a diode enclosed in a plastic tube plus theres a second one up there. Not to worry anymore about those.

The black/yellow batt voltage enters the heater housings harnesss.......then goes to a IGN relay........leaves the Ign relay and splits off and goes to three places. It goes to the light green/black wire at each of the two relay plugs and also goes out of the heater housing harness and connects to a single wire plug and goes to the Logicon from there.

The series four wiring picuture is vague in that it does not show wire colors at the relays and other places. The series five does show the wire colors but it does not show any Ign relay internal to the housing like on a series four. So thats what makes it difficult for me to figure out whats going on.
The purpose of the Ign relay is to turn the blower off when your trying to start the car. It opens up the circuit that feeds the relays.

Then you throw in a 1987 wiring diagram and it's different from the 88 wiring diagrams. Kinda sucks.
In the jpg of the eight socket plug you can see that single wire connector next to it. Later. Busy today.

 

If you have batt power at the black/yellow, then ask yourself a question. Have you done ANYthing to the starter circuit that is not stock? Like rig a switch to start the car, or the like?

That Ign relay on the heater case will interrupt the power to the blower relays if not wired right at the starter circuit.

 

i tested the black/ yellow wire in the 8 pin plug and it does have power... and i do have a turbo timer that was installed when i bought the car so who knows what kind of wire job is on that thing...that is the only thing that has been done to the starter circuit..

 

i cant tell you that the turbo timer seems kind of screwy...when i put my windows up and they get the whole way closed, if you still hold the switch up the turbo timer makes some loud crazy buzzing sound..doesn't seem right, could mean the wiring is screwed up..i will be tearing my whole dash out to do a interior swap this sunday or next weekend so all the wiring will be exposed and i can access everything... so what does it mean that i do have power at that black/yellow wire? could those diodes be bad? or that ignition relay? i have a parts car that i can swap these parts over if that may help..

 

You have power on the yellow/black. Good. That is also the power to the IGN relay. Unfortnaltey the coil for that relay also needs a ground, and it seems your missing that ground.

In the attached jpg I have the ground for that coil colored BLUE. It does have something to do with the diodes but I'm not sure if they're the problem.

It's an odd arrangement for me. The relay contacts are open normally. Then you put the key to ON and for some reason the relay latches and closes the contacts and feeds the coils on the Heater Relay and Ex-Hi relay. And it stays latched unless you go to START. Then the relay opens and kills the power to those two relays causing the blower to stop blowing.

I didn't have time today to figure it out. I did look at the neg side of that coils and it reads like .85vdc and I was looking for a ground in ohms. So that confused me a bit. Still does.

I can see where the black/yellow feeds the coil.......then the juice goes thru the coil to the neg side of the coil and goes to one diode that heads back to the pos side of that coil.........and it also goes to another diode that heads for the starter circuit. So I"m a little confused about that.

IF anybody knows how that relay pulls in, just step up to the plate.

I think I'm going to extract the black/green wire out of that eight socket plug tomorrow and see if that relay still pulls in or not.

One thing I'd like to try is make a jumper wire. Connect all relay/plug up, and jumper b/t the yellow/black and the light green/black wire at that eight socket plug. That would bypass the Ign relay and the damn thing should work like a normal car, except the blower would keep blowing if you went to Start. Then again, just turn the blower off with the slider.

Fact is, I'm going to pull that IGN relay out and then do just that. Make a jumper wire like mentioned above and see what happens. It'll work, I'm pretty sure. Don't need no stinking Ign Relay.

 

Why wait for tomorrow. I went out and jumpered the light green/black to the black/yellow and the fan works normal. I pulled the Ign relay prior to doing that.

In case you missed it, the light green/black leaves the heater housing as a hot wire, and goes to feed the Logicon or part of the Logicon.

The second jpg is from my 1987 manual and I tried to show how the light green/black feeds the AMP in the Logicon. At least it seems that way. Your original Logicon may be good.

 

so should i go out tomorrow and jumper the light green/black to the yellow/black and see what happens?

 

At the first crack of dawn. The light green/black is in a connector near the eight socket connector your already familiar with. Have all the plugs connected up and the slider anywhere to the right and key ON.

The only reason it might not work is if the Logicon does not put a gnd on the Heater Relay. But I bet it will do that. I can hear the blower whirring from here.

 

lol ok..if i had a garage at my house id do it now but im not that fortunate.. i will check in the morning. thanks

 

wait...is that green/black wire the one that is in a single connector by itself? i think i remember seeing it

 

That's the one. Jumper the yellow/black in the eight socket plug to it.

Jpg attached shows how the green/black not only feeds those two relays ..Heater and Ex-Hi relays, but also feed numerous transistors inside the Logicon. I colored the line in red.


EDIT: Normally the light green/black gets fed by the Ign relay and THEN the light green/black feeds the Logicon. If you do the jumper, then the light green/black will feed parts of the Logicon and the two relays we've been fooling with earlier.

 

awesome..from the looks of that diagram the logicon should spring to life when i jumper those wires. ill let you know in the morning..id check now but its like 15 degrees outside and my car is sitting in 12 inches of snow and ice..your in texas..lucky bastard haha

 

Unlike the the President, I have the signature of BOTH mother and Father on my birth certificate!

This is just a FYI: You need to leave the light green/black wire connected up. I mean you don't just disconnect it and then jumper the yellow/black to one half of that connector. The light green/black connector has to be left connected together. But you somehow jumper b/t it and the black/yellow wire in the larger connector. I think you know that, but just in case I write this.

Yeah, the air mix motors and all that stuff should now work again.

Gone for the day.

 

ok i jumperd those two together and i hear both of the relays kick over but the blower dosent kick on

 

I attached three jpg Trying to show how the Green/Black interfaces with the scheme of things. I colored the green/black in a light green so the black stripe might not show up.

It gets power at the Ign relays plug IF the relay pulls in. Then leave there and goes to a splice a half foot down. From there it goes two places. One is to the single wire plug and the other is to one of the two relays....heater relay and Ex Hi relay, to power the positive side of those relay coils.

If the IGN relay was accessable, then you could pull that plug off and jumper the two TOP sockets (top being the ones near the locking device) and that would simulate the relay having been pulled in.

I kinda hope this works out for you .........because I'm outta ideas..almost.

Or heck, a person could just jumper a switched source of power to either of the green/black wires AT the relay plugs. The green/black are all spliced together, so if you power one you power all green/black.

 

I finally figured out what causes that Ign relay to pull in. It gets fed power by the black/yellow for the positive side of the coil. The negative side of that Ign relay coil is given a ground by .......the starter solenoids coil any time the key is NOT held to Start. When you go to Start then that wire going to the Ign relay has voltage on it and the relay relaxes. Let the key return from start to On, then there is a ground on that Ign relays neg coil and it pulls in once more.

The ground wire for that Ign relay comes from the BG (black/green) wire in the corner of the eight socket plug on the heater housing. So you could disconnect that eight socket plug, and put a meter on the BG wire and see if it has a ground on it. Mine reads approx 10ohms. I then pulled the small wire off the starter solenoid and the meter went to megaohms, proving that it is the small wire on the starter solenoid that supplys the gnd to the Ign Relay to pull it in.

Now that I've cleaned out the leaves in the heater and figured out how the thing works, I'm going to put it back in the car. Lotta leaves and junk in the core.