pacman777

Problem started with no Hvac blower function including fan speed controller or in defrost position -- zilch nada -- so upgraded with Rogers new blower motor . Switched out all relays & fuses checked out resistor pack ,freezer switch---all functioning.Moved on to control head unit relay. Mine was MeteorGrey's Gruner 970 fix with Radio Shack relay upgrade & it worked.But fuse 8 kept blowing so moved on to Wally's compressor clutch check , wiring & fuse panel checks, & 14 pin connector checks --- all good. Decided to go in completely different direction ---Ignition switch swap --- voila car starts, heater blows, all speeds including defrost --but now car won't shut off unless not on defrost. Swap back the other ignition switch --- same --- wtf --can both ignition switches have same problem or maybe the ignition switch plug ?

Kiln_Red

If I am understanding correctly, did fuse #8 quit blowing only *after* you swapped the ignition switch? Sounds like you disrupted the short to that circuit while swapping the ignition switches and, now, the RUN circuit stays closed regardless of switch position.. Check your ignition switch pigtail for bare wires. That would appear to be the most obvious place to check. Definitely sounds like it is in the wiring as both ignition switches are behaving the same way.

Ducman82

ya know, mine use to do that. some how power was feeding back when the HVAC head unit was in a "certain" position. id just slide it back and forth and it would stop....... damn old units..

Alan

So car won't stop when head unit is in DEF position - but otherwise will?

Does the HVAC work correctly otherwise? AC works, blower works, flaps & temp work?

If these still don't work correctly - and seemed you were chasing it for a long time - then you probably screwed up somewhere in these fixes. I'd particularly check the HVAC head relay fix.

Ignition switch could be a culprit - but if both behave the same - probably not.

The symptom you describe commonly occurs when a relay that is fed both 30 & 15 links the two together due to some internal fault... This happens commonly with a failed rear defroster relay.

It has nothing to do with 50.

Are you sure you put the replacement relays in the correct position - it is not as obvious as it seems - you must pay attention to relay labels and esp. the little arrow tags - they are not consistently placed wrt to the relay sockets they apply to...

Alan

pacman777

thanks kiln_red. checked the harness today, at the connector and it seems to be fine. no burning or arc marks on the wires. i didn't check past the harness wrap though. maybe there?

pacman777

that's right alan. everything else works head unit wise. but what is 30 & 15?

pacman777

i should add that both ignitions are old. one is original and one is used

Kiln_Red

Terminal 30 &15.

Alan

30 is battery direct - input to the ignition switch and direct supply to many relays, 15 is ignition switched supply from the ignition switch - this being powered is what keeps the car running (on with key in position 2,3 [of 0-3]), X is accessory switched power (on with key in position 1,2) , 50 is the starter tip switch to the starter relay (on in key position 3) R is switched radio supply (on with key in position 1, 2). P is Park power - used for parking lights (on in key position 0).

Alan

pacman777

Thanks Alan , this is complicated stuff , & I'm not great with auto electrics. Are you saying that it might be my rear defroster relay? I already changed my front defroster relay without the fuse tester , just a regular 53 is that ok ?

rexpontius

Also check if the defrost knop is not sticking in the pushed - in position.

Try pulling the **** and see if the car shuts down.


Cheers

17prospective buyer

I remember this happening on my 87 and people said it was a relatively common problem when a relay gets stuck closed and current backfeeds somehow to provide enough power to the ignition system and whatever without blowing a fuse. Dunno how that works.

pacman777

Thanks, if you are referring to the slider ***** I believe they are in the regular position. And PB this happened to you ? Do you remember which relay? I've already refreshed panel with all new fuses & new Hella 53 relays including a 53 for the Front defroster but not the rear defroster relay, just waiting for confirmation from Alan . Do you guys think it's ok to drive the car like this?

Alan

A regular '53 relay is fine in DEF - functionally the fuse tester relay is the same as a normal SPST '53 relay (the fuse tester part is just grafted on and doesn't change the relay function at all - can be located wherever a '53 goes, or left out).

Make sure the relays are where you think they are - really check this - I know you think its impossible you did this wrong - but many many people have done this before...

BTW PB is talking about something quite different... However for testing you could remove the rear hatch defroster relay and see if it makes any difference - I doubt it.

Alan

pacman777

Thanks Alan. I checked the relays and they are in the correct positions and are the correct relays. I checked relay x and it is functioning correctly. I checked the nofreeze switch and the resistor pack and both are functioning properly. I pulled the control head to see if my work was ok and it is, but the board is now burnt on pin 6 and pin 1. What is pin 6? Could this be the problem or is the constant power from the ignition the problem? Remember the car would only turn off if the defrost is off.