voltage drop please help????

[dennis1993]

hello all i recently purchesed a 1987 turbo t last october drove it a bit then put it to sleep til last month. over the coarse i changed to 60lb injectors, new fp regulator, walbro pump with hw kit ,tt alky chip, razors alky kit, new scanmaster 2.1 and powerlogger just to give you a basic idea of some mods. ok problem is at idle voltage at back of alternator is 14v scanmaster shows 12 to 13v set boost to 19lbs chip burned for 24 to 25 started to log some runs at wot and lo and behold the voltage drops to 11.2 to 11.8v then knock? checked all grounds tight and good
if anyone has any ideas i would GREATLY appreciate the advice! thank you in advance<

Dennis

 

[IrvJr]

I had the exact same prob. Turned out to be the alt, but it could be many diff bad connections. Is that a stock alt or a 200 amp one? I recently found out some 200 amp alts have a smaller pulley and that could causing an issue.

 

[GSTOY]

check the alt light bulb holder. I was having the same problem and found that the holder had a dirty connection. Clean the connector that the bulb plugs into, especially the back side of the holder that makes the connection to the isnstument cluster wiring. It could also be a dirty connection on the instrument cluster harness that plugs into the back, but you will need to pull the instrument cluster in order to clean it.

Steve

 

[dennis1993]

thanks for responces irvjr and gstoy it is not a stock alt it is a chrome plated but lot if numbers are worn so cant tell amps? and as soon as i get some time ill try to check dash cluster but i think its gona be a nightmare because it has a gnx style dash and who knows what kind of a wiring mess is behind there anyone have any other ideas where to look?

 

[GSTOY]

Try this...

Casper's Electronics, Inc.: Field Fix Harness 1986-1989 GN/TTA

Steve