No start after heater core replacement

[2000StreetRod]

wiring diagram

Below is the wiring diagram for your vehicle.

Your ground (G200) is different than mine (G204) but it probably is in the same location. I don't have the shop wiring diagram for your year to determine the actual location. It also looks like you don't have the mid-way connector like mine does. Splice S235 probably has other ground returns connected so if G200 is loose then multiple things (seemingly unrelated) won't work.

 

[dieselphreak]

Okay. I did not see a ground wire on the driver's side kick panel. Or even a spot to ground at.

 

[dieselphreak]

Should also add that I have taken the rubber hammer to the tank, with no results.

 

[2000StreetRod]

kick panel

Did you have the driver side kick panel off? Did you pull back the carpet on the driver side?

Did you disturb the areas shown in the photos below?

 

[dieselphreak]

Yes. Pulled that area of carpet up, didnt see anything. Did have that kick panel off as well. Only pulled the carpet back to the point where i could see where the harness goes under the sill panel. I was laying on the floor on that side for quite some time, but I was on top of the carpet on my back re-attaching the steering column. I don't think anything would have been disturbed.

 

[2000StreetRod]

what voltage?

Power to the inertia switch is good. Bypassed switch and still no fuel pump.

Was the voltage to the inertia switch battery voltage or just a few volts? If just a few volts you could have read the input voltage of the PCM pin that monitors the fuel pump relay voltage.

 

[dieselphreak]

Actually used a test light there. One pin had a full brightness. One didn't have anything. The small wire lit the bulb very dimly.

 

[2000StreetRod]

S235

I think the splice marked in the photo below is S235 on my 2000 Sport. The grounds for the stop lamps are part of the splice.

It's more likely the splice was disturbed than the actual ground connection.

I wish you had the voltage for the inertia switch. The small wire (dim bulb) should be the wire going to the instrument cluster. Check the instrument cluster for some kind of fuel warning. If the inertia switch is closed (not tripped) then both of the large wires should have been bright bulb if there was power thru the fuel pump relay. What you read might have been the voltage of the input to the PCM.

 

[dieselphreak]

Okay. I have 12.5 at the small wire. .5v on one large wire. 12.5 on the other, dropping to 7.2 after a few seconds. This is with the connector unplugged from the inertia switch.

 

[dieselphreak]

I think the splice marked in the photo below is S235 on my 2000 Sport. The grounds for the stop lamps are part of the splice.
View attachment 88257
It's more likely the splice was disturbed than the actual ground connection.
.

I can see where this runs inside of a harness holder plastic type thing. It's being a pain to get out. It seems unlikely that this would be disturbed, but i'm going to attempt to access it anyway.

 

[2000StreetRod]

jumper at the connector?

Power to the inertia switch is good. Bypassed switch and still no fuel pump. . .

Okay. I have 12.5 at the small wire. .5v on one large wire. 12.5 on the other, dropping to 7.2 after a few seconds. This is with the connector unplugged from the inertia switch.

When you bypassed the inertia switch did you disconnect the connector and insert a jumper wire in it? If so, then that means that battery voltage was going toward the fuel pump. So either the wire from the inertia switch to the pump is open, the pump is bad, the ground wire from the pump to the splice is open, or the ground wire from the splice to the chassis is open. Unfortunately, since all of the ground wires are black it is difficult to determine which comes from what (fuel pump, stop lamps, etc.). The easiest thing might be to probe a black wire aft of the splice and measure the resistance to chassis ground at any convenient location. If it is only a few ohms then you know the splice and ground are good. If it reads open then probe on the forward side of the splice. If that reads only a few ohms then you know the ground is good and the splice is bad.

 

[dieselphreak]

When you bypassed the inertia switch did you disconnect the connector and insert a jumper wire in it? If so, then that means that battery voltage was going toward the fuel pump. So either the wire from the inertia switch to the pump is open, the pump is bad, the ground wire from the pump to the splice is open, or the ground wire from the splice to the chassis is open. Unfortunately, since all of the ground wires are black it is difficult to determine which comes from what (fuel pump, stop lamps, etc.). The easiest thing might be to probe a black wire aft of the splice and measure the resistance to chassis ground at any convenient location. If it is only a few ohms then you know the splice and ground are good. If it reads open then probe on the forward side of the splice. If that reads only a few ohms then you know the ground is good and the splice is bad.

I did manage to find the spice. It APPEARS good. Followed it froward from there, and found the ground located under the kick panel. We didn't remove the inner panel, so i had never seen it in the dash removal process. It is undisturbed.

When I put the jumper in the interia switch connector I put it connecting the terminals of the two larger wires. I am assuming this is the correct move.

 

[dieselphreak]

I also still do not have brake lights. This leads me to think it is a ground issue, but the ground wires appear a-ok forward of the splice.

 

[2000StreetRod]

rear park lamps?

The rear park lamps and the brake lamps use the same grounds.

Do the rear park lamps work?

 

[dieselphreak]

Yes, they do. Probably an unrelated issue.

I've thrown in the towel. I get 2 days a week at home. I've given this wreck 3 of them so far. It's past my knowledge at this point. It's being towed to a shop.

Thank you for all your help. I really do appreciate it.

 

[Westsidedee]

What did the shop come up with I am having the same problems.

 

[Paytonboyd91]

I have all the same issues and have done all the same troubleshooting. Still no start. Did anyone figure this out?