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2008 Buick Lucerne Fuel Pump Relay

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Buick Ownership
Lucerne, Lesabre
I noticed a few minor differences between the original and the one I bought off of eBay. I was a little worried, at first, but after checking the service manual, it doesn't appear that any of the missing fuses are used for anything...at least not on my CX. Haven't run into any issues since swapping fuse boxes.

Here is the original

And here is the one I bought off of eBay (with the 88953222 fuel pump relay installed...in place of the one that came with the fuse box)

The missing fuses are described in the 2008 Lucerne service manual as follows:
No / Device / Rating / Description
#3 / Run3 Fuse / 5A / Not Used
#11 / MDL-RR Fuse / 20A / Not Used
#23 / SWS-RR Fuse / 20A / (Z75)
#27 / NAV Fuse / 10A / (Z75)

Just replace mine as well, the fuse box I got also was missing these 4 fuses. (08 Lucerne CXL) Not sure what systems they go to. Interested to know what you found out. Will continue reading this thread maybe its been answered. Since mine had fuses and connectors in the box and the new one didn't have connectors or fuses.
 
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3
0
1
Buick Ownership
Lucerne, Lesabre
Talked to a friend of mine who works at a GM dealer and a tech. As century 76 stated, my new box was missing the four fuses too. He said that the lucerne was basically a Cadillac with a different trim. And most likely wiring harness and fuse box on the same production run. And those fuses are for the Cadillac DTS. Fuse 3 - Run3 Rear Blower, Fuse 11 - Rear seat heat module, fuse 23 -Rear Lumbar and fuse 27 Navigation. Hope this helps
 

2007LucerneCXL

Full Member
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862
113
Illinois
Buick Ownership
2007 Lucerne CXL. and 1995 Lesabre currently, past 1973 Riviera, 1968 Riviera
Just asking what you are talking about? This is on the fuel pump relay TSB and fix for the fuse box.
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3
0
1
Buick Ownership
Lucerne, Lesabre
Just asking what you are talking about? This is on the fuel pump relay TSB and fix for the fuse box.
Yes, I had the same problem replaced the relay then decided it was best to replace the fuse box as well. the fuse box I got to replace the orig one was missing those four fuses (3, 11, 23, 27) also as a previous member stated and was missing four fuses. and wanted to know what they are and if I needed them (with the replacement fuse box/block) for any accessory I might have. I was just addressing the missing fuses that might not be in the new fuse box if anyone ordered one to replace the one they had and it was missing those.

Sorry if it caused any confusion
 

tsleber3

Buick Newbie
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Buick Ownership
Buick
Re: [SOLVED]Re: 2008 Buick Lucerne Fuel Pump Relay

I own a 2008 Lucerne and have the EXACT same problem as Century61. Exact same burnout of the fuse block at the exact same location. Car wouldn't start and I was lucky to find the problem myself without paying a lot of money. Replaced the relay and it works for now while I'm waiting for a new fuse block. I ordered an OEM one from the big auction site for $19.95, far less that the $300 the dealer wanted.

Here is what I think is going on. The original relay coil gets hot normally or gets hotter than normal because of an internal coil short. In the original relay design, the coil housing is part of the switch circuit and basically pin 30 is a continuation of the coil housing. Thus the heat of the coil is transferred preferentially to pin 30 because of the way the relay is designed. This heat causes a loss of temper in the connector in the fuse block which leads to a poor connection and more heat. The loss of connection may be exacerbated by plastic insulation which melts inside the relay and flows down the pin. Eventually, the connection is lost and the car won't start. I think Buick is aware of this because the new relay I bought from them has been redesigned so that there is no longer thermal continuity between the coli housing and pin 30, and the coil housing is no longer part of the switch circuit. Also, the new relay coil ohms out at 145 ohms vs. 90 ohms for the old relay. The coil wiring on the new coil is finer than than it was on the old coil so I think this is a design change to cause the coil to run cooler, rather than just indicative that the old coil was shorted. Moreover, if you take the cover off the relay and run the engine, you find that the coil housing is the first thing to get hot, not the switch. So, again, I think the design of the original relay was flawed because it allowed this heat to be transmitted freely to the connector in the fuse block.

Fixing the problem requires replacing both the relay and the block because the connector in the block has been irreparably damaged by the defective relay.
What is the part number of the replacement relay? Ted Leber tsleber3@netzero.net
 

tsleber3

Buick Newbie
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Buick Ownership
Buick
Has anyone tried replacing the fuse box-block themselves? is the box-block just plug and play, so to speak?
thank you!
It takes less than ten minutes. There are four clips that hold it in the base. I flex them back with my pocket
knife. The fuse block comes up (kinda 'folds' to the rear). There are three 72-pin connectors on the bottom
held in by one screw in the center of each block. When you unscrew the screws they will unplug the connector.
there are two more small connectors. Compress the clips and pull them out. viola! that's it.
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