WIRING FROM STARTER RELAY TO STARTER? Help!

[ilm65]

With two electric fans pulling 23 amps each, I replaced my OEM 46 amp alternator with a 75 amp Powermaster. I upgraded the charge wire that leads from the alternator to the starter relay to 8 AWG with a 12 AWG fusible link. With the OEM 14-16 gauge running to the starter, am I defeating the extra charge intended to recharge the battery? If I upgrade this wire to 8 or thicker gauge, will my charge improve? The battery's in the trunk with 1AWG running to it. ANY HELP???

 

[ilm65]

Still need some input; Thanks in advance.

 

[tpodwdog]

thicker wire = less resistance. i have some advice......get rid of the electric fans and put the battery up front where it belongs. you asked for input....there it is!

 

[Sweet5ltr]

I run an electric fan/Mechanical fan combo as well. I have the battery in the back, WHERE IT TRULY BELONGS and it is wired directly to the starter with around a 0-2G wire. I actually ran a wire from my alternator, to the starter relay for improved charging along with using the factory harness. This way it bypassed the interior electrical system and powered straight to the battery. This wire was around an 8G wire. This way has worked for me, but I am also only pulling around 20 amps but with a factory (A/C-HD) style starter which is 60 amps. I only use the electric fan during heavy traffic and it doesn't even budge the voltage gauge.

 

[Propwash]

Doesn't sound like you're running into a wire Gauge issue...More like you're sucking a ton of amps. 46 AMPS for your fans to run. If you're running a 55/60 Watt halogen..that's another 10 AMP's...Electric fuel pump would add another 4-10, if you have one. Turn on the wipers, another 10...Incidental stuff another 5-10... Your 75 AMP alt is peak charge. That does not mean at idle you're seeing 75amps at 700-800 RPM. You're probably seeing around 50 at idle or low RPM. Mix that all together, easy to see why you have a Low charge/discharge issue.

 

[HT413]

Sorry, are you sure you're pullinng 28 amps each?? Most 12" fans pull 7-10 amps ballpark and 16 fans pull more like 8-12 amps.

My thinking is this - in the event that the draw is closer to 15-20 amps TOTAL for both fans, rewire everything back to stock (except for the battery relocate kit) and return that oversized alternator. It might even save a couple of horsepower if you're interested in that.

Then just wire the fans to never come on while the starter is engaged and unless you have other big draw equipment like a massive stereo, you'll be within the limits of the OEM alternator. It would be simple - get a normally on relay and have it wired so when the ignition solenoid gets the signal to engage the starter motor, this secondary relay will get the same signal, which opens it, thus killing the fans. As soon as you stop cranking the starter, the relay closes again and your fans operate as normal.

 

[dvw]

I'm assuming you charge path is alt stud (8g) to starter relay to starter (12g) to battery (1g).
If so replace the 12g with 8g to complete the upgrade.
Doug

 

[Jasoncoronet]

Propwash hit the nail on the head. Get a bigger alternator this ia a comon problem with Mopar units. I hate to say but they suck at charging. That 50 to 55 amps is probaly actually 35 amps at idle. Many aftermarket alternators mainly GM based will put out 75 to 100 at idle believe it or not.

 

[68 Sport Satellite]

He said he is now using a 75amp powermaster....

 

[ilm65]

Sorry, are you sure you're pullinng 28 amps each?? Most 12" fans pull 7-10 amps ballpark and 16 fans pull more like 8-12 amps.

My thinking is this - in the event that the draw is closer to 15-20 amps TOTAL for both fans, rewire everything back to stock (except for the battery relocate kit) and return that oversized alternator. It might even save a couple of horsepower if you're interested in that.

Then just wire the fans to never come on while the starter is engaged and unless you have other big draw equipment like a massive stereo, you'll be within the limits of the OEM alternator. It would be simple - get a normally on relay and have it wired so when the ignition solenoid gets the signal to engage the starter motor, this secondary relay will get the same signal, which opens it, thus killing the fans. As soon as you stop cranking the starter, the relay closes again and your fans operate as normal.

Good info HT413--Thanks!

- - - Updated - - -

He said he is now using a 75amp powermaster....

Just took delivery of a Tuff Stuff 100 AMP Square Back--let's see how this performs and I'll post the results. Thanks for all the input--this is a great site!

 

[67 coronet]

i always hook up all my electric fans to a manual switch so i can control them.
current setup in this project only pulls 24 amps and creats 4600 cfm of air flow!dual fan as shown.

 

[ilm65]

i always hook up all my electric fans to a manual switch so i can control them.View attachment 102722
current setup in this project only pulls 24 amps and creats 4600 cfm of air flow!dual fan as shown.

Thanks 67 coronet--I see you're running two Flex-A-Lite fans. Mine are Spal (both good brands) but are 23 amps EACH along with an electric fuel pump--had to install a separate relay and fuse block so I didn't overload the OEM system. My fans are thermostatically controlled, but I think I'll also install a manual switch so I can control when they're on. I'm hoping the Tuff Stuff 100 amp alternator will solve the charging problem. Thanks for your input!

 

[ram250098]

In passed cars with high elecric needs what I have done is change the battery ground to a 4 ga then I also run a 4ga from the block to the frame then I run a 4 gauge from the battery to the alt. They call this the big three...google it alot of the stereo guys use it to prevent loss of power when the high amp stereos are cranked.
AL

 

[67 coronet]

In passed cars with high elecric needs what I have done is change the battery ground to a 4 ga then I also run a 4ga from the block to the frame then I run a 4 gauge from the battery to the alt. They call this the big three...google it alot of the stereo guys use it to prevent loss of power when the high amp stereos are cranked.
AL

thanx ram.good grounds are very important to make a stable high power electrical system.
i still think that seems like a high draw for your fans ilm65.i also run extra fuses and relay anything added to my electrical system.better to be safe then sorry.

 

[ilm65]

In passed cars with high elecric needs what I have done is change the battery ground to a 4 ga then I also run a 4ga from the block to the frame then I run a 4 gauge from the battery to the alt. They call this the big three...google it alot of the stereo guys use it to prevent loss of power when the high amp stereos are cranked.
AL

Hey ram250098, Our Mopars (and mine too) currently run from alternator charge post to the starter relay on the firewall. Can I leave that connection in place and run a second 4 awg directly from the alternator charge post to the positive side of the battery? If that's feasible and considering my battery is in the trunk, can I run it directly to the battery connection on the starter and bypass the starter relay? Thanks in advance, Bob

 

[Nacho-RT74]

ANY ALECTRIC ACCESORY MUST BE SOURCED FROM ALTERNATOR NOT FROM BATT/STARTER RELAY... on ammeter cars.

and if you link with a wire the alt stud with batt/starter relay stud, you are bypassing the ammeter

 

[oldbee]

I've always used #2 ga. welding cable for battery cables.More flexible than "battery cable", finer strands of copper. Always remember that bigger cable is better, no matter what you're running. Course, then we get into multiplexing (crap) where smaller gauge wire works just as good. We don't want to go there...

 

[67 coronet]

I've always used #2 ga. welding cable for battery cables.More flexible than "battery cable", finer strands of copper. Always remember that bigger cable is better, no matter what you're running. Course, then we get into multiplexing (crap) where smaller gauge wire works just as good. We don't want to go there...

stop talking above my head,it hurts my neck to look up!

 

[ilm65]

ANY ALECTRIC ACCESORY MUST BE SOURCED FROM ALTERNATOR NOT FROM BATT/STARTER RELAY... on ammeter cars.

and if you link with a wire the alt stud with batt/starter relay stud, you are bypassing the ammeter

I would think I'm also bypassing the voltage regulator; not a good thing?

 

[747mopar]

Something nobody ever mentions much is the Ammeter, I want you to think about something. How many amps is your ammeter made for (the stock 40-50 amps) what are you putting threw it now? Like he said ALL of the current has to go threw it for it to be accurate, fire hazard if you ask me. Don't like them won't use them, voltmeters are a far better and a safer alternative plus you can plug them into virtually any 12V wire and your done.