I have a 89 T2, stock fuel pump. I haven't tested the voltages yet while boosting. I'd like to re-wire the pump to give it the full 12v. Is the stock wiring that bad, that I can't use the existing wire and wire in a relay to give it 12v?

Thanks

 

uh that's what rewiring is, you use the existing wire as a trigger for a relay and then run new wire straight from the battery to actually deliver the juice. It's a little more complicated with a T2 because it has a low voltage mode and a high voltage mode. You could bypass that if you want to though. That will save you some trouble but result in poorer fuel economy.

 

gotcha. I was always under the impression that a "rewire" was just feeding a full 12v to the pump at all times. So an actual "rewire" still retains the low and high? except that your getting power straight from the battery?

Thanks

 

There are options, but I would highly recommend to just wire the fuel pump straight to a full +12VDC power.
That PIECE OF **** switching relay with the resistor is already a bad source of voltage drop due to corrosion and wear + tear.
Eliminate it ensures you get full power no matter what.


-Ted

 

^^ there are writeups on how to incorporate the two voltage settings, but **** it. If you bypass the two-stage system and are putting the relay together, you would want the old fuel pump wire on the 86 terminal, a chassis ground on 85, +12V from the battery on the 87 terminal, and the 30 terminal will be +12V out to the pump. That is how you would wire up an N/A at least, which has no 2 stage thingie.

Double check all that of course before you put it together.

 

Correct.

http://www.1300cc.com/howto/how2/rewire.htm

It's funny how if you have any problem with any stock part in your car it's immediately branded a "piece of ****" that must be removed no matter what. I know you had the relay fail on your car but that is a very uncommon problem. You're the only person I've ever heard complain about it. I know when I did the full rewire on my car the relay was in excellent condition with negligible voltage drop though it, this despite the surface corrosion on the sheetmetal bracket that supports the relay and resistor.

Wiring the pump up with full-time battery voltage will simply increase fuel consumption when the pump's supposed to be getting reduced voltage, which is most of the time in normal driving. There is no advantage to this apart from removing the very tiny risk of the relay failing closed (even you admitted this was very unusual). If you're really worried about this, the stock relay can be easily replaced with an inexpensive and reliable 30A automotive relay.

 

I was thiking "why not just replace with a new one" and you said the same thing.

If it's old, corroded, fucked up in general... why not do what you do for everything else on the car... fix it properly.

 

Here's what my rewire kit looks like.

 

don't use a radioshack 30A relay, they are garbage. I've had several go out on me with my electronic auxilary ports

 

Why not just buy a new Circuit Opening Relay and a new Fuel Pump Relay and Resistor and be done with it? Maybe throw in a new Main Relay to boot.Yes, that's the way.

 

i'd like to know some things about the rewire i know i need alot of wire to run from the battery to the pump and also from the resistor and relay back what all do i need to buy for the rewire i want to buy all the right stuff so i can go ahead and wire my new pump up fuses relays ect

 

All the parts you need are listed in the link I posted above.