Jumping starter relay with momentary switch

[Montclaire]

Hello, this is on a 73 Dodge. I'm dealing with a hacked up harness and the car refuses to fire off of the ignition switch. It will crank reliably if I jump it at the starter relay. Rather than keep using a screw driver I'd like to temporarily hook up a momentary switch in the cabin. What is the minimum gauge of wire that I should use for this? What should the minimum rating for the switch be?

Thanks

 

[toolmanmike]

I usually overkill but I would use 10ga.

 

[bearman]

Do overkill like the toolman says you never know.

 

[Nacho-RT74]

if you want to trigger from the relay... any 16 gauge wire will do the job, between stud and IGN prong. That will make it work just like the stock setup, feeding the SOL output through the relay itself. Stock IGN wire coming out from bulkhead is 18 gauge in fact

 

[Aarons Air]

Why not leave that type work to chevy owners ?

 

[Montclaire]

Why not leave that type work to chevy owners ?

Normally I would but the car is getting sold and I'm not putting a new harness in before it goes. The harness has several sections spliced in and sections cut out. Am I right in that the prong for the neutral safety just acts as a ground? Wondering if I should try running a jumper to the neg on the battery and see if it cranks off the key. I did inspect the plug for the NSS and it was clean/fit snugly but I did not check it or the NSS with a meter.

 

[Nacho-RT74]

no need to ground it to batt.... the relay attaching screw will be more than enough ( 16 or 18 too )

 

[WP29440SE]

I have and use a clip on push button starter switch that does exactly what a screwdriver does. I use it for many reasons including bumping it over for torque converter bolts.

 

[toolmanmike]

Like I said, I usually overkill. The quality remote starter switched are 12 gauge.

 

[Montclaire]

Awesome, thanks guys. I'll try bypassing the NSS first just in case.

 

[toolmanmike]

I have and use a clip on push button starter switch that does exactly what a screwdriver does. I use it for many reasons including bumping it over for torque converter bolts.

And adjusting valves.

 

[Nacho-RT74]

Like I said, I usually overkill. The quality remote starter switched are 12 gauge.

View attachment 968169

maybe to use it without a relay, but a straight feed... using a relay, no need for that.

 

[Nacho-RT74]

is funny to see 12 gauge wires but that funky weaky clips to hold "suposselly" the load the 12 gauge would hold LOL.

and still being strong clips, the contact surface is minimal related to what a 12 gauge wire is able to handle

 

[toolmanmike]

The chart says 41 amps for 12 g. I know the relay doesn't take 41 amps to trigger. Unless there's a short or some other issue. I sold hundreds of 12 g. jumper leads and they would come back to me looking like a toaster ribbon. Oops.

 

[Nacho-RT74]

Maybe they used it straight to sol terminal... just like triggering straight at starter motor ???

 

[69L48Z27]

Like I said, I usually overkill. The quality remote starter switched are 12 gauge.

View attachment 968169

I have one of those for testing under hood. Also comes in handy for adjusting valves like you said. The big wire on the starter direct to the battery is where the load is. Those buttons with 12ga are more than capable with those clips to trigger the solenoid.

 

[RJRENTON]

I usually overkill but I would use 10ga.

Typically, use the same gauge wire that would energize the relay thru the ign switch....#14 AWG, will be just fine.
BOB RENTON

 

[Nacho-RT74]

Typically, use the same gauge wire that would energize the relay thru the ign switch....#14 AWG, will be just fine.
BOB RENTON

Yes that could be a logic reason, but at the end the wire arriving to relay is 18. So 18 or 16 should be enough.

 

[Rusty 72]

Since we're on the topic of wire gauge, is there any downside to using a wire rated too big for what you're doing? or is it like a single car going down an empty 5 lane freeway. Just unused space?