Electrical Jumping alternator dash wire after digital dash install?

Grn92LX

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#1

• Jan 9, 2021

• #1

Just looking for verification. Im in the middle of installing my Holley efi 6.86" pro dash. I know I need to jump the wires on pin 2 and 14 on the factory harness to turn on the alternator. Can I just run a simple 14g wire jumper or does it need a resistor soldered in? If so does anyone know what resistor I need or does anyone make a jumper plug n play harness? Thanks

 

Blown88GT

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#2

• Jan 9, 2021

• #2

IIRC, 500 ohm resistor

 

jrichker

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#3

• Jan 9, 2021

• #3

Grn92LX said:

Just looking for verification. Im in the middle of installing my Holley efi 6.86" pro dash. I know I need to jump the wires on pin 2 and 14 on the factory harness to turn on the alternator. Can I just run a simple 14g wire jumper or does it need a resistor soldered in? If so does anyone know what resistor I need or does anyone make a jumper plug n play harness? Thanks

Click to expand...

Any 1/2 watt, 500 Ω resistor, or any 1/2 watt resistor between 470- 560 Ω if you can't find a 500 Ω resistor

 

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Grn92LX

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#4

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Thanks, got the resistor ordered. Now what would be the best way to do this without cutting the factory wiring? Would a T tap connector on each wire with the resistor soldered in between work ok? T tap-jumper wire-resistor-jumper wire to T tap ? Or does anyone make a plug and play harness?

 

Blown88GT

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#5

• Jan 10, 2021

• #5

Grn92LX said:

Thanks, got the resistor ordered. Now what would be the best way to do this without cutting the factory wiring? Would a T tap connector on each wire with the resistor soldered in between work ok? T tap-jumper wire-resistor-jumper wire to T tap ? Or does anyone make a plug and play harness?

Click to expand...

Yes.

 

Grn92LX

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Jan 17, 2021

#6

• Jan 17, 2021

• #6

Everything worked like a charm, thanks. How hot does a 1/2w 470ohm resistor get? I put a wire covering over the entire jumper I made so it won't touch anything. Is that ok?

 

mikestang63

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Jan 18, 2021

#7

• Jan 18, 2021

• #7

sorry for jumping in on this.... putting together my autometer dash for the 90 vert. Am going to put a 500ohm 0.5 W resistor between wires 2 and 14 on the classic dash wiring plug - the two pink wires- even though the instructions do not say this is needed nor did their tech support .. can you post the link to where you bought your resistor?

Wondering if I should also as backup install a 194 bulb between pin 2 and 14 even if not visible for insurance.

 

Grn92LX

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Jan 19, 2021

#8

• Jan 19, 2021

• #8

I got it from amazon. Came in a 100 pack for $6, needed 1 now I have 99 left.

Amazon product ASIN B0185FIDF0View: https://www.amazon.com/Projects-100EP512470R-470-Resistors-Pack/dp/B0185FIDF0/ref=sr_1_3?crid=3M74Y75N8VPOQ&dchild=1&keywords=500+ohm+1%2F2w+resistor&qid=1611081560&sprefix=1%2F2w+500+ohm%2Caps%2C185&sr=8-3

 

mikestang63

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#9

• Jan 19, 2021

• #9

thanks...

 

Grn92LX

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#10

• Sep 9, 2021

• #10

I just realized after installing the digital dash with the 500ohm resistor jumper wire that I used a 1/4watt and not a 1/2 watt. I am starting to notice a sight voltage drop as I get into the higher rpms and also noticed slightly less voltage at idle. It used to be around 14.6 @ idle and now it’s 14.4-14.5 and it also drops to 14.3 in the upper rpm range. Could the wrong resistor be causing this?

I am also noticing a sight fuel pressure drop in the same upper rpm range as the voltage drops. This seemed to happen once I installed the dash and I’m curious if the wrong resistor is the issue?