1996 VLCM repair

[psychostang]

Hi all. Tuesday night, my VLCM failed on the way home. Driving along at 75mph on I-4, and engine shut off. It acted like it wanted to start, but no joy. I figured it was not the fuel pump. I was right. Had to call my brother who was in town from New Jersey, as he has AAA. Replaced VLCM with a spare and vehicle started right up.

Now for the $64K question, where can I send the broken VLCM to get repaired. It's either the FPDM or PWM circuitry that failed. Has anyone sent ther unit out to be repaired? Thanks for any assistance.

 

[budpytko]

Prob easier to just buy one (and cheaper). Check Ebay.

 

[Lvnmarks]

Get a hold of Bruce or Carlos on here, they will likely have a replacement.

Haven't heard of someone repairing these, although I am now curious to what the inside looks like.

 

[SilverMark97]

Why not just rig up a relay (as some of us have done) and leave the damn fan on all the time?

 

[chris2523]

i tried that, the 30 amp draw all the time was not kind to my alternator.
so i just fixed it properly with another vlcm/vrcm from carlos.

 

[mag]

SIA electronics repairs ECM'S 1-800- 737-0915 .I agree a constantly running fan makes no sense why are we trying to reinvent the wheel.

 

[psychostang]

Thanks. How did we get from fuel pump to fan? :confused-red: I know I could probably find another one, but I have one in the trunk anyways. I just wanted to get this one fixed, cause you can never have enough 1996 VLCM's laying around.

 

[Mad1stGen]

It's a dumb relay box. Open it up, replace the burnt up relays, and reassemble. I am sure the actual relays are the same between all year VCRM or VLCM so you can use any year for donor parts. Yes, the relays are soldered in place.

Oh, and RE fan on all the time, it would created more airflow restriction than help if the car is at speeds say 50 and up.

 

[HOTLNC]

Actually, it's more than relays. Besides relays, there is a microprocessor in there and some power electronics to supply the PWM (Pulse Width modulation.) I looked inside my old one, with the thought of repairing it. But the PCB (Printed Circuit Board) is coated with epoxy based conformal coating to keep moisture out. That makes repair damn near impossible to do unless you have the stuff that will melt the coating. And since there were no schematics, there was no way to troubleshoot the problem.

Yes, you can bypass to get the fan running (my problem.) But with no A/C, that bypass would be too high a price to pay when it gets 110 degrees outside.

Send an email to carlos mejia <racebronco2@yahoo.com>. His part saved HOTLNC.

 

[psychostang]

That's the thing with the fuel circuit on 96's. The primary system is not a relay. Its basically power put thru a pwm circuitry to slow down the pump when fuel pressure is not needed. The High speed or full power relay is in the power distribution box. If push comes to shove, I'll just connect the ground wire from the pcm to the excitation circuit for the relay. NO big deal.

 

[chris2523]

i didn't think the 96 was a PWM setup.
that was the 97/98s with the FPDM.
am i incorrect? wouldn't be the first time.

 

[psychostang]

The FPDM on 96's is in the VLCM. 97/98's moved it to the rear of the vehicle. That's why 97/98 vlcm's are mounted close to where the air ride compressor is.