Continental heated winshield

[Lord Iffy]

Hello,

sorry for spaming with a little off topic, but I have problem with 1990 Lincoln continental. There is something wrong with the charging system. Alternator and battery shall be OK, but almost every time after ride and a day of standing, the battery is empty. I believe that there could be some problem with the heated winshield option - I could not find heated windshield and thus it has been replaced by regular winshield. I think that the heated winshield system is causing this trouble, because there is relay which switches current from ALT to this heated winshield system instead of to the battery. I wanted to rewire it, but I am not able to find this relay (it is called alternator output control relay). I have only shop manual and it says between RH front fender and the inner fender splash shield - I have no idea where it is and how to get to it. I believe I would find it in EVTM.. And the other problem is that I think the alternator is not grounded - there are 3 outputs and only two of them are connected, unfortunately I could not find any loose wire which I shall connect to the third one.. Thank you

[91grandmarquis]

Shouldnt it not relay the power to the window unless the button is pushed for the rear defrost? Maybe im wrong though.

[GM_Guy]

Was the heated windshield disabled? There is a tsb on bypassing most of the electronics/relays that run the system.

TSB 94241 NOV 94 Heated Windshield - Conversion to Regular Windshield

I'd look it up but my computer is refusing to work with the Ford CDs for some reason.

If you have an EVTM, you can go a lot further to take all the heated windsheild nonsense out of the car.

Alex.

[Lord Iffy]

Was the heated windshield disabled? There is a tsb on bypassing most of the electronics/relays that run the system.

TSB 94241 NOV 94 Heated Windshield - Conversion to Regular Windshield

I'd look it up but my computer is refusing to work with the Ford CDs for some reason.

If you have an EVTM, you can go a lot further to take all the heated windsheild nonsense out of the car.

Alex.

Unfortunately it was not disabled and now it is messing with the charging system (and maybe other things - I believe the radio stopped working at same time - but there could be other reason). I know about that TSB and I like to do it according it (http://www.glasslinks.com/tips/htd1.htm), but I have to locate the relay (I already did) and the control module, unfortunately I do not have EVTM for this car, only shop manual. I am not sure why should I disconnect the pin No. 1 on the control module, maybe that is the current source for the whole system (what and why should be done with the relay is pretty clear). The control module is somewhere in the interior and I really hate to do anything there, but I will have to...

[Lord Iffy]

Shouldnt it not relay the power to the window unless the button is pushed for the rear defrost? Maybe im wrong though.

I am not sure, whether it has any connection with the rear defrost. I have EVTM only for my car (89 marquis) and according to it heated windshield and rear defrost are connected - there is only one switch for both, but in continental there are two switches - one for rear defrost and other for heated winshield, so I believe these two circuits could be separated

[85crownHPP]

They are independent... easiest thing would be to figure out which fuse link at the starter solenoid is for the front heater windshield and disconnect it there.

[gadget73]

you have to do it at the relay otherwise the alternator gets shut off any time you turn the defrost on. If the wiring for that stuff was hacked up, its impossible to say what it may be doing. I'm pretty sure both the front and rear defrost run on the same switch, though I'm not super familiar with the Continentals.

[GM_Guy]

I am not sure why should I disconnect the pin No. 1 on the control module,

Becuase its required in order to do a proper disabling of the heated windshield system...

Heres what happens when you turn on the defroster/heated windshield;
-alternator is disconnected from the cars electrical system.
-car and _all_ accessories run off battery ONLY.
-alternator full fields
-output from alternator is fed to heated windshield.
-after the predetermined amount of time the heated windshield is automatically shut off and the alternator is switched back to the cars system to charge the battery.
-if everything is working properly, if battery voltage falls to low, the heated windshield will turn off (automatically) and the alternators output again feeds the car.

Thats why it needs to be disabled properly. You don't want the system to inadvertantly to switch out the electrical system and full field the alternator.
Ideally, you trace it out with the evtm so you can remove any possible future issue (like a funky relay whose contacts are corroding).

Alex.

[85crownHPP]

I want to say Ive seen separate front/rear defrost switches on 90-91 boxes... right on the front of the dash with the antenna and rear defrost switches. Haven't seen an older box with the front defrost grid though so I cant say for them.

[gadget73]

89 and older have just one switch, it controls both front and rear defroster. Its marked somehow differently, W/S De-Ice or something, but its in the same location as the rear defrost switch.

He's talking about a Taurus Continental though, and I know squat about those.

[85crownHPP]

Yep - i didn't find any heated windshield info in my 85 EVTM, but the 91 EVTM shows it has its own switch and its power source is indeed tied pretty deep into the alternator wiring. Looks like a big scary mess... you may want to consult a pro.

[91waggin]

90-91 has separate front-rear deicer switches. The "W/S deice" switch is right in the middle, between the antenna and rear-def switches. It shows it in my 91's owner's manual

[Lord Iffy]

thank you all! It looks rear and front are really independent - there are two switches - one Rear Def, second W/S Ice. I did it according to the TSB and it looks that the heated windshield is now disabled.

This is the control module (pin No. 1 disabbled)


This is the relay


And somewhere here was the relay located (took me some time to find it..)


But enough of continental, tomorrow transmission goes to marquis and I hope, it will work