Cdsquared0

I have a 1986 Monte Carlo SS with a 2000 F Body Ls1 in it. I bought a pre made harness from tech rods for it. It has a brand new 180 amp alternator, and a new 900cca battery in it. The battery is in the trunk and there are ground straps to the frame,firewall,engine and starter. My problem is that at the battery with a meter it shows 13volts and in the car on the automated gauge it shows 12.5. When I turn on the lights it goes down, the AC it goes down further and when the dual Fbody fans come on it plummets to 10.5 volts at idle and 11.5 at cruise. At idle with all accessories on it shows 12 with a meter on the battery. I know the voltage regulator is good because the stocker I had on previuosly did the same thing.

Does anybody have any ideas?

chucklaw

iTrader: (2)

Just had this problem on my RX7. Changed the regulator to a self exciting one. Problem solved.

http://www.norotors.com/index.php?topic=197.0

ramairetransam

iTrader: (18)

Can't see pics on that site

chucklaw

iTrader: (2)

Might have to sign up to see the pics.

Cdsquared0

The regulator is actually turning on because if I unplug the exiter the voltage at idle will drop from 12.5 with no accesories to 10. So I think that it's working somewhat just not enough. What is the voltage that I should get at the exiter while running?

89 formula350

iTrader: (8)

whats the voltage at the alt.? ive seen many remans that were no good so I wouldn't put too much faith that yours is

oange ss

iTrader: (50)

what size battery wire do you have going to the trunk ? Confirm the alt exciter wire goes straight to pcm pin Red C15

chucklaw

iTrader: (2)

I get 14.1 volts at the battery. Got 12 volts before changing the regulator. And the alternator was brand new.

chucklaw

iTrader: (2)

I was also getting 12v at the PCM with the old regulator. I would just pull the alternator and get it tested (take it to auto zone or equivalent). If it's charging, then put in the new regulator and forget about the red wire to the PCM. I've had nothing but problems with charging issues and that was the cure for me and many other RX7 LS1 swaps.

Cdsquared0

I have a 180 amp version of the stocker, do you think the self exciting regulator with work? The case is the same size as the stock one? This may be the route I go because even though I ordered the harness specifically for a2000 Ls1 the little red wire is actually brown like the 98's. I will look to see where it goes when I get some time tomorrow.

chucklaw

iTrader: (2)

Should be the same.

S10xGN

iTrader: (11)

The brown (exciter) wire should go to the negative side of the charge indicator lamp on the dash. This wire is ground (thus, the lamp lights up with key on & engine off) until the alternator starts rolling. After the alternator is rolling, there is 12v on that wire (no more current flow & the lamp goes out).