Fabrice Tschumi

OK, so my charging system is up at almost 14 v during the day but at night with my headlights on it reads somewhere between 12-13 on the dash, sometimes on the higher end, sometimes on the lower.

I got my starting/charging systems tested. 13.8 no loads, 13.6 loads. starter good, battery good

Got my battery terminals replaced, and it kind of helped, but now im thinking of redoing my battery cables. already got the cables and connectors and such.

MY question is this: can i run a new alt wire straight off the battery to the alt? does it have to go through the fusible link block?

can i also replace the short wire from the battery to the links with a new one while im at it?

essentially, can i run the alt wire (white/red) straight to the battery or will it **** something up?

misterstyx69

iTrader: (142)

Personally I would just leave it alone.
If you are not experiencing any Drop off voltage that effects the cars running ability then you are trying to fix something that is not broken.
Your alternator Charges your battery not the other way around so even if you run a Cable to the battery (which by rights should already be in the loop) you are accomplishing nothing.

JSmall

Here's a good alternator thread which is definitely worth a read
AusRotary.com ? View topic - Alternator upgrades

I suppose giving the alternator +12 terminal a clean would be nice. But as above. It doesn't sound like you really need to replace anything

Fabrice Tschumi

The fact that it doesnt supply more than 12.75 with headlights on is not an issue?

and according to the part number on the alt its a 70 amp model, apparently from an 86/87 626

KansasCityREPU

iTrader: (9)

One way to improve the headlight voltage drop is to switch to a headlight harness like BlackDragon use to sell. Keeps the current away from the column switch using relays. You should be able to find an equivalent harness on eBay. Look for a two headlight version that has relays.

GSLSEforme

KansasCityRepu gives good advice for relayed headlight harness taking load off factory wiring and switches,however i think op is concerned about system voltage. Are you testing the voltage at the battery,at idle? If you raise engine speed to a fast idle does voltage go up to 13.5-13.8 and stabilize? Check and post back. Do you have original alternator from car? Possible the 626 alternator has different size pulley than what oe was,compare with original. You said you had new battery cables.... install these,pay attention to body ground on left strut tower,make sure metal on body and connector is clean and bright,do not omit this. If you are using a generic cable without this ground lug,you'll have to fabricate something to duplicate it . Point to all this is to eliminate voltage drop in your system so you can move on to further diagnosis. Doing this will surely result in maybe .5 volt improvement or better. Don't overlook power wire coming from alternator,especially the connector at the alternator,if it looks oxidized,corroded or some of the strands are broken,cut it off and put a new one on. Crimping AND soldering is best. If after all this if charging voltage is not 13.8-14.5 at the battery,you may have a problem with the alternator and or a sulfated battery. Put a known good battery in car and retest system voltage,still reading low? Take alternator off and have it tested,if place you take it to says it's good,take it to another place for another opinion to eliminate it as cause of problem. At this point you will have narrowed down problem or fixed it altogether. Post back with your results...

chuyler1

iTrader: (1)

Upgrading the "Big 3" as they call it in the car audio world with thicker gauge wire can help.

1. Engine Block to Chassis (multiple if possible)
2. Alternator to Pos Battery (always fused within 18" of the battery)
3. Neg Battery to Chassis


The first is a big help, as all current generated by the alternator has to pass back to the engine block through those tinsel wires that connect the block to the chassis.

The second is only really important if the car's fuse box is also connected to the battery. If a separate wire goes from the alternator to the fuse box, that's the one you should upgrade, and yes it needs a fuse.

The third isn't very important at all. Very little current passes through it while the car is running. It is used heavily when starting the car, but after that it's more of a trickle. The exception to that is a high output stereo that puts excessive strain on your regulator. In that situation, the stereo often draws current directly from the battery because the regulator can't adjust fast enough to the changes in current demand.


However, with all that said, your description of the charging system seems "normal" to me. Mine barely keeps it above 12.5v with the lights, wipers, heater, and defroster running. It hovers around 13 at night, and 13.5 during the day. These 80's cars were never intended to charge at 14.4 volts like the cars of today.

GSLSEforme

Barely above 12.5 volts is not normal and is not what they operated at when new. Cars are now 30+ years old and over time all kinds of resistance creeps into wire harness from corrosion and plain old oxidized connections. It's possible to have voltage drops in several places in a circuit from excessive resistance,each of these responsible for .2-.3 voltage loss per fault. Fix these,now you have 13 volts+,and these cars can and do charge at 14-to 14.2 volts. On a 12A car,a SE alternator can be swapped in-it's a bolt on and nets 60 amps. Going to really heavy cables is not really necessary in a stock application. As stated in a previous post, a relayed headlight harness goes a long way to giving you brighter lights with much less current draw than the stock lighting circuit allowing other accessories to benefit from less power consumption of the hea.dlights

t_g_farrell

iTrader: (1)

Relay everything, headlights, ignition, fuel pump, electric fan(s). It makes a huge difference. The
root of the problem is old wiring and the fact that all these items when not relayed with a direct
hot lead for power have to get the power through the circuits that the switches are one. That
means all the amps for the headlights go through the switch that the stalk uses to turn them on,
same with the ignition and fuel pump (ignition switch where the key is). This is why a lot of times
the ignition switch has to be replaced.

JSmall

Got any known good links for how to relay ignition and fuel pump at all?

miasmicmonky

iTrader: (1)

I will agree here. I don't see at all how this could hurt. I decided for the $20 for a kit on ebay, might as well since I had good results on a Big 3 kit on my Protege.

Fabrice Tschumi

Did 2 of the Big 3, need to run a new ground from block to chassis still
new wire from batt to main fusible links
new coils
without headlights its still at 14 ish, idle or not
with lights on its above 13, at speed
lights on at idle its at the high end of 12

getting a headlight relay harness shipped, will install next week most likely and report back

t_g_farrell

iTrader: (1)

This is one of the best sites about everything lighting on a car and the relay article will fill you in.

Daniel Stern Lighting Consultancy and Supply