Recent Posts

1

Electrical / Re: 87 R10 dual tank pump issue and hot fuel module

« Last post by Captkaos on Today at 08:58:36 am »

The Oil pressure sending unit is a backup system to the Fuel pump relay.  Fuel Pump Power through this switch is also cut if the engine stops running as the oil pressure will drop.
This is a good post by Hatzie on the operation of the 87-91 pump dual tank setup: http://forum.73-87chevytrucks.com/smforum/index.php?topic=37007.msg310663#msg310663

So are you sending switched voltage to the tan/white wire, which is turning the pump on in Start and Run?  AND the Oil Pressure Switch?  (note this will keep a pump running all the time)
If wired correctly the switch should divert the power from left to right. (see link above)
Technically you could run switched power down the "test" lead also and achieve the same, but I would use it to Test the pump with isolated power.
Have you checked the wiring after the switch to see if you are getting alternating power Left or Right when the switch is changed?

(I forgot to hit post yesterday, sorry)

2

Electrical / Re: whiper troubles again

« Last post by zucchi on Today at 08:22:45 am »

Since the wipers operate by manipulating ground rather than power, I suspect this is a grounding issue. I would reestablish the ground and/or add a redundant ground strap for the wiper switch.

3

Electrical / whiper troubles again

« Last post by NCali on June 17, 2026, 06:04:06 pm »

(I put the link here instead of the copy/paste, and this is a continuation I am move this post to that same one. -Captkaos)
I wrote the following thread some tine ago.  http://forum.73-87chevytrucks.com/smforum/index.php?topic=39789


then I changed the switch and the wiper motor and that fixed thee problem until now. Driving down the road the wipers came on and would not shut off. To get home I unplugged wires 17, 18 and 19, 3 and 4. today I plugged those wires back in and the delay module instantly got hot. unplugged the delay module and tried to put the connectors together but the wipers didn't run. with the switch in the off position I no have power on #4 , 17,18 and 19. my next step will be to separate the delay module to see if I can find a short
 or another delay module
any thoughts?

4

Electrical / Re: 87 R10 dual tank pump issue and hot fuel module

« Last post by Ocho on June 17, 2026, 12:14:12 pm »

Thanks Chris. Since the relay uses that short pulse from the ECM to prime and a signal through the oil pressure sending unit, I provided 12v to those inputs since I don't have the ECM to do that. My guess is that's where the problem lies. Would you agree? Since I can't just add a 5 second prime signal, it's 12v continously. Just not sure how to wire the relay. Should I just get a different relay that doesn't need those extra inputs to pass 12v?

5

General Discussion / Re: 20 years

« Last post by zieg85 on June 17, 2026, 12:04:30 pm »

Thanks for the reminder.  I loved your restoration build.  Thanks for sharing.  I hope to continue on my 2 builds with write ups.  Life gets in the way and even though I built my dream shop it is so packed I can't work on either at the moment very easily.

Dang that was a long time ago.  I guess Chris's site has stood the test of time.  Best Chevy truck site on the web.

Life has a way of getting in the way.  I've had 3 cars since I got the truck, one crashed, ones my fav daily driver ever and one is my new project.  But the old truck just carrys on.  Only been towed twice in 48 years.  not a bad record.  one for a frozen brake caliper and one for the fuel lines rotted so bad the engine was sucking air.

After I got my 85, I found this site in 2004.  Someday I will get around to finishing my frame on restoration.  Meanwhile it is sitting out of the elements and last time I checked, no foul odors from varmints.  First picture is the day I brought it home.  The second was in 2010 after an encounter from a deer.  I started collecting parts and soon after I took it out of commision.  Someday I will make a post but it will not hold a candle to yours.

6

Electrical / Re: TCC lockup pin location

« Last post by Captkaos on June 17, 2026, 10:03:06 am »

Terminator as in Holley?

7

Electrical / Re: 87 R10 dual tank pump issue and hot fuel module

« Last post by Captkaos on June 17, 2026, 09:59:54 am »

The tan/white wire would just be the wire which sends power to the left or right tank based on the switch position.
The gray and tan wire from the switch determine which side pump to excite along with controlling the switching valve.

From the fatory the intank pump(s) should come on when the relay is triggered for about 5secs (estimate) base on the ECM trigger. 
Do you still have the relay in use? 
If you are using a carb, what are you triggering the relay with (if in use)?
It sounds like you have this wired incorrectly as the tan/white is just a trigger wire from the relay and the switch determines where to send the power= left or right tank.

8

General Discussion / Re: 20 years

« Last post by 78 Chevyrado on June 15, 2026, 10:15:34 pm »

Lift Kit part 3

The splash shields for the disc brakes were so nice i just cleaned them and they still had the galvanizing visible.  now you know how they looked factory.

9

General Discussion / Re: 20 years

« Last post by 78 Chevyrado on June 15, 2026, 10:14:19 pm »

Lift Kit Part 2

10

General Discussion / Re: 20 years

« Last post by 78 Chevyrado on June 15, 2026, 10:13:18 pm »

8-2008 lift kit.  Lifted the truck while rebuilding the front end by installing 454 front coil springs (I have a small block) and adding 1.5" lift blocks in the rear.  Had to get a new steering box because the hit was hard enough it wrecked that too.  Far int he future but now it has 275/70R18 tires on it that fit with no scrubbing.