electrical question
 

Just wondering if anyone else has the same problem. Everytime I use the rear defogger on my 90 LX, it draws so much voltage that the battery gauge drops to 11 volts. Does the defogger actually draw that much power or is there something wrong?
I am going to upgrade my alternator to a powermaster 130 amp model to help the problem.

Re: electrical question
 

You might have a wire grounded out somewhere, or your alternator and battery may be on the fritz...

Do you have underdrive pulleys? Does your radio, window motors, or anything else cause a similar effect? :confused:

Re: electrical question
 

no pulleys, stereo only when I turn it up. I'm thinking about replacing my ground wires with a thicker gauge

Re: electrical question
 

The rear defogger draws huge amperage. Its on a 30-amp circuit and if you trace the wiring, its at least 10-gauge back to the defogger. As outside temps go down, resistance goes down and the current draw will go up. I think what you're seeing is normal for a rear defogger.

Re: electrical question
 

The upgraded alternator will help out a LOT......

Re: electrical question
 

Rear window defoggers pull mucho power. Heck, they are a heating grid, like a toaster. Upgrade the alternator, it will help.

Re: electrical question
 

I have a similar problem, but my voltage gets into the single digits, and I have a powermaster 165A alt.
It seems to be worse when it is colder.

Can anyone explain to me.

thanks
jason

Re: electrical question
 

how much was your 165amp alternator? It's about $240 CAD for a 130 amp powermaster up here.

Re: electrical question
 

Check into an alternator for a 95GT at the parts store.

Re: electrical question
 

I looked into that but b/c the housing is bigger from the 95, you have do some mods like grinding down my bracket. Of course wiring has to be upgraded.

The powermaster comes as a direct replacement, so it has same size housing. Just the wiring has to be upgraded.

Re: electrical question
 

The bracket doesn't get cut much at all - it's very easy. And if your upgrading amperage and not re-wiring with the correct wire sizes, your asking for trouble and possibly a fire.

Re: electrical question
 

Not my Powermaster! I did have to do some grinding.
I don't remember seeing any high output alts in the stock cases.

I have no idea what the alt cost me, as it was several years ago. I do believe it was more than ~$250.
I can tell you that it costs $100 to rebuild it. This big of an alt does not like to be rev'd to 6k rpm. It can handle it a few times, but eventually blows up.

Re: electrical question
 

the defogger (90 GT)also puts a big drain on my autometer voltage gauge. so does using the front windshield defroster or "mix" on any fan speed. fan speed #4 (highest) also drains my juice a lot as well. naturally the a/c does damage as well. i put in a 130A PA Performance alternator that i bought for $200 a few years back. the alternator install did require a couple minutes of grinding, very simple. also got a march 1000 pulley setup from PA Perf. (around $100)and they installed the alternator pulley on for me. i also upgraded the wire from the selenoid to the alternator to 4gauge as recommended by PA. ($40?) also replaced the pos and neg battery cables and started cables. ($40?)now my voltage still drops when i use the defogger, but not nearly as much as it used to. the drop is only noticable when at idle, anything over 750 rpm's and she charges great.

Re: electrical question
 

thanks guys