What Did I Do???

[BigT]

I was working on replacing my heater core, here is the forum for that problem:

http://www.grandmarq.net/vb/showthread.php?47878-New-Heater-Core-No-Hot

I took apart the dash to include removing the cluster panel. I started the car off and on while fixing the vent doors in the plenum. I had the car doors open for long periods while working on the heater core and dash. Well I noticed that the windows were getting slower going up and down from the dome lights burning. So I ran the car for awhile so the alternator would recharge the battery. It got worse. I pulled out the volt meter and its only charging at 11.5 and dropping.

So today I replaced the old alternator (life time warranty) with a new one. They did not check the old one to see if it was working, They took my word that it was only charging at 11 volts. I put a charger on the battery while I went to O'Reillys.

I put the new alternator in and the same thing. Now its 11.77 volts and dropping. When I 1st did the 3G upgrade it was around 14 volts.

So I know I did something. Does the dash cluster panel need to be installed to complete a circuit? (Its still off). Is there something under the dash I might have disconnected by mistake causing this?

Other than the no charging, the car runs fine. I had arched things in the past with my truck and it was always the distributor module I would fry. I would think that would have fried before the alternator.

Any help would be appreciated!

(Called the parts store for them to test the old alternator, they'll get back later with the results)

[tjc78]

As far as I know, the "AMP" light needs to be connected in order for the alternator to be charging (completes the curcuit). Try plugging in the instrument cluster and I bet all will be fine.

[BigT]

Thanks! I hope your right!

[pantera77]

Thanks! I hope your right!

He is, instrument cluster needs to hooked up for the alt to work.

[grandpaslincoln]

Whenever you work on your car like this you need to unhook the battery.

[1990LTD]

Your alternator won't charge at all with no bulb in the circuit. Should be fine once the cluster is installed again.

[zoomie]

you had car doors open, any light that are illuminated will help drain a battery

[Lincolnmania]

x3
gotta have the instrument cluster installed or the battery will not charge

[sly]

x3
gotta have the instrument cluster installed or the battery will not charge

+1 This.

[BigT]

It's good to hear I need the instrument cluster in for the charging to work. I was getting a little stressed that I pulled a wire by accident and would take me a forever to figure out where. I'm waiting for LED lights I ordered before putting back in the cluster. I will give a status update after the cluster is installed. Thanks again for easing my mind!

[gadget73]

just don't change the battery lamp to an LED. it probably won't kick the charging circuit on.

[GM_Guy]

It won't. Besides the resistance, the amp light needs to be able to operate bi-directionally. (depending on operating mode, and failure mode).

Alex.

[pantera77]

Unless you have my bastardly wired 89 who's entire AMP light section is missing yet the alt works fine.

[fmansfield444]

If the bulb is blown will it still charge?

[BigT]

Now you tell me! I just got the LED bulbs in yesterday and plan to install them today. Since I have everything this far apart, I'll try it with both LED and regular bulb. BTW, I have a heck of a time getting the speedometer off (may have broke the plastic), is there an easy way for that to come off? I hope It's not damaged enough to reuse.