Hooked up HO alt with external regulator, Now car wont start

[lilmaniac2 5,000+ posts]

did you hook up the external regulator. ie the little blue box? if so how is it wired? is the alt free spinning? ( that is can you spin it by hand? )

 

[bookechu 10+ year member]

the alt spins by hand, everything as far as the alt works fine once the car is started. On the regulator is increasing, counter or clockwise?

 

[audioarsonal 10+ year member]

Clockwise to increase counter to decrease.

 

[goodstuff 10+ year member]

Sounds like a bad fuel pump if it only turns over when you spray ether into the intake.

 

[jdawg 5,000+ posts]

Sounds like a bad fuel pump if it only turns over when you spray ether into the intake.

a fried ecu wont turn on the fuel pump

I am betting you had that sucker cranked up to like 18v and fried the ecu. Not once have you mentioned that you check it with a dmm to see what the actual voltage is that its putting out

 

[bookechu 10+ year member]

I didn't use a dmm, but the mechanic had this meter that clamps onto the battery that showed its charge. Worst part is that I have a 98 gC, which makes it that much harder to find a replacement unless I buy a brand new ECU.

 

[bookechu 10+ year member]

Well I found a new ecu for 280shipped, should be here by Tuesday. What else could have possibly caused this(ecu burning up)? I believe I turned the voltage all the way down before we attempted to crank the car, but I may be wrong. I also have the 12volt on the blue box tapped into some 20amp fuse in the fuse box that only comes on when the ignition is on. Is this the wrong way of hooking up a 12volt turn on source?

 

[audioarsonal 10+ year member]

What you need to do is wire in a relay and use the direct power from the battery.Use the current fused wire that comes on with your vehicle to turn the relay on and off.Ground the "blue box" and the relay together and run the field wire to your alt.All this should be done in at least 10ga. wire I used 8ga.Before you start your vehicle this time check the dial to be SURE it is all the way to the left and have a dmm handy.

 

[bookechu 10+ year member]

at least 10g? I have an 8g ground and freakin remote wire for everything else. I'll change it out asap. I got my truck running, it was the ECU. Now the problem is that the truck is charging at 12.2v, but the truck idles at around 4-500rpm. What could be the problem? Also because my truck is charging at around 14.5 -14.8 while i'm driving my volt meter keeps going off the scale and "check gauges" keeps coming on. How do i disable this?

 

[audioarsonal 10+ year member]

My check engine light stays on because I disconnected the factory harness and wired up a new one from a harness I got from the junk yard.So I just deal with it I don't know if you can disable it without just remving the bulb. because the computer isn't getting a reading back from thealt is why it is doing that. But my voltage on my meter in the truck reads consistant and I have it set at 14.7v.With your idle that low you may not get any output.Most alts don't pt out until around 2400 rpm alt speed about 800 rpm engine speed.Thats with a 3 to 1 pulley ratio.4-500 sounds pretty low though mine does about 650-700 warmed up.

 

[bookechu 10+ year member]

I guess i'll raise the idle on my truck just a tad. So does your factory voltage meter read or do you have another one set up in the truck. I think if I disable the factory hot wire that goes to the alt, my volt meter wont read and the check engine light will stay on. Will this do it?

 

[jdawg 5,000+ posts]

280 used? I probably could have come close to that new.

 

[audioarsonal 10+ year member]

It's my stock gauge.I left my stock wiring in place so i can hook it up and let the ECU control the voltage or I can unplug it and use the external regulator.I think the gauge reads from a direct wire that is controlled by a relay and not the ECU.I'll check into that though.I would say your charging fine as long as there are no major voltage spikes.It will rise and fall a little but nothing above 14.7-8 or youll be buying another ECU.I got a couple pics to give you an idea how i have mine set up if you want to check it out?

 

[bookechu 10+ year member]

sure, get that to me asap