Strick,
I would be very cautious about using the ignition coil wire. Although this is a switched ignition circuit, it can cause some serious performance problems should a fault of any kind occur. I am going from memory here ~ but most switched wires in the GM ignition system are orange. Chris Houston (Vette92) went thru some trial and error scenarios when finding the best source for power. Let's let him provide feedback on this particular subject.

In answer to your question regarding review of your Tech Tip.... I would love to do so. I write procedures and technical articles for my real job :crazy: . A well written procedure can save time and help the end-user avoid mistakes.

As far as relays are concerned.... these are the specifications you should look for:

12 Volt DC
20 (or 30) Amp Heavy Duty Contacts
DPDT (double-pole/double-throw)

I prefer a relay with a base ~ but most automotive relays do not come that way

Lastly, I prefer DPDT relay because it provides you with a spare set of contacts in the event that one set should fail. This may be a lifesaver on a hot summer day out in the middle of nowhere. With that said though, I would never install an electric water pump without a 30 amp manual switch that allows you to bypass the relay and turn the pump on manually in the event of total relay failure.

~ Purp


[Modified by PurpleC4, 2:25 PM 6/3/2003]

 

I would be interested in hearing this as well. I have not yet had problems with using the ignition coil wire (maybe I just have descent wiring), but was a bit nervous about it at first. The first one I tapped into was one of the fan relays, but had all kinds of problems with it.. (it worked fine for a while, then stopped working when the AC was on, then worked again.. crazy stuff..) If there is another good circuit that I can tap into (that turns on when I put the key in the accessory position) I would feel more comfortable with it.

-Mark

 

I had problems running it off of the fan relays as well. They were hot in the run position, but cold with a running motor. The engine temp would get too hot as the water pump would not spin.

I have a few accessories that I run in my car. Almost all of them are powered off of a relay system that I put in place using the center console accessory wire. I use this wire to trigger a relay which triggers other relays that are used to activate my accessories like my nitrous, gauges, electric water pump, RPM window switch, bottle heater, etc. Nothing I am running can be turned on without the key in the run position. I think I have probably 6-7 different relays in my car right now just for accessories. Most of them are in the cockpit away from the heat of the engine compartment.

 

Sounds like a good place for the 12 volt battery feed would be right behind the battery where the large gauge red wire attaches to the terminal. I'm still looking for a good signal source to tap into. I also like the idea of a manual switch to bypass the relay in case of failure. Where should the switch be, in the cockpit or under the hood? In most airplanes, there would be a warning light to let you know the pump is not receiving electrical power and you would just switch to a back up. I wonder if this would be workable.

:flag :flag :flag

 

Which fan relay wire are you guys grabbing? I've been using the fan relay without issue since the install.

Just curious.


[Modified by 96GS#007, 1:01 PM 6/4/2003]

 

Strick... My schematic incorporated the warning lights and the bypass switch. I also built a prototype box that attaches to the passenger side of the radiator shroud for easy access. You and I are on the same wavelength...
~ Purp

 

I do not recall, but it was the one people suggested to me. I have a manual fan switch on the relays and it works fine. Not sure what I did wrong when I tried to use them for power but I would say I used the wrong wire ;). I like the way I have it wired up now anyway so it was no big deal to fix the problems as I fixed a couple other electrical issues I was having at the time as well.

Chris

 

I just installed mine 2 weeks ago. I replaced the opti and pump at the same time but I didn't remove the timing cover. No leaks so far. My biggest problem was trying to install the pump on the block because the A/C accumulator was in the way. I had to put the pump in first and move it forward past the accumulator, install the pump housing to the block then attach the pump to the housing. I wired mine through a 30 amp relay directly to the battery with the relay controlled by the fan signal. I also wired an indicator light (LED) and mounted it in the dash which will light if the relay or fuse fails. Also I replaced the dinky fuse that came with the pump with one in a weatherproof housing. I also agree about the pump seal (o ring). Buy a new one from GM.

 

I was going to do a tech tip on this as well, but since purp does it for a living (tech writing), he should probably be the one to do the text. However, I can provide some pics (42 so far) that I had in progress... :) Here are a few, but if you want all of them, shoot me an email.

 

Your idea sounds great. How about we make this part of the tech tip article? Or is this something you want to sell? I'd think about it.